CA1201274A - Rapidly dissolvable silicates and methods of using the same - Google Patents
Rapidly dissolvable silicates and methods of using the sameInfo
- Publication number
- CA1201274A CA1201274A CA000403443A CA403443A CA1201274A CA 1201274 A CA1201274 A CA 1201274A CA 000403443 A CA000403443 A CA 000403443A CA 403443 A CA403443 A CA 403443A CA 1201274 A CA1201274 A CA 1201274A
- Authority
- CA
- Canada
- Prior art keywords
- silicate
- powdered
- potassium
- range
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims abstract description 41
- 150000004760 silicates Chemical class 0.000 title abstract description 23
- 238000005755 formation reaction Methods 0.000 claims abstract description 76
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 75
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 60
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 30
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 30
- 239000000203 mixture Substances 0.000 claims abstract description 26
- 229910000272 alkali metal oxide Inorganic materials 0.000 claims abstract description 22
- 238000007789 sealing Methods 0.000 claims abstract description 22
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims abstract description 16
- 239000011591 potassium Substances 0.000 claims abstract description 16
- 229910052700 potassium Inorganic materials 0.000 claims abstract description 16
- 239000011734 sodium Substances 0.000 claims abstract description 16
- 229910052708 sodium Inorganic materials 0.000 claims abstract description 16
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910052783 alkali metal Inorganic materials 0.000 claims abstract description 6
- 150000001340 alkali metals Chemical class 0.000 claims abstract description 6
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 110
- 239000000243 solution Substances 0.000 claims description 106
- 235000019353 potassium silicate Nutrition 0.000 claims description 68
- 239000004111 Potassium silicate Substances 0.000 claims description 60
- 229910052913 potassium silicate Inorganic materials 0.000 claims description 60
- NNHHDJVEYQHLHG-UHFFFAOYSA-N potassium silicate Chemical compound [K+].[K+].[O-][Si]([O-])=O NNHHDJVEYQHLHG-UHFFFAOYSA-N 0.000 claims description 60
- 239000004115 Sodium Silicate Substances 0.000 claims description 50
- 239000004568 cement Substances 0.000 claims description 45
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 44
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 44
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 30
- 239000002245 particle Substances 0.000 claims description 29
- 239000000843 powder Substances 0.000 claims description 26
- 229960003975 potassium Drugs 0.000 claims description 15
- 239000012530 fluid Substances 0.000 claims description 14
- 235000007686 potassium Nutrition 0.000 claims description 14
- 239000007864 aqueous solution Substances 0.000 claims description 11
- 239000012267 brine Substances 0.000 claims description 11
- 150000001768 cations Chemical class 0.000 claims description 11
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims description 11
- 239000011575 calcium Substances 0.000 claims description 10
- 229910052791 calcium Inorganic materials 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 9
- 229910052925 anhydrite Inorganic materials 0.000 claims description 8
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 7
- 238000001035 drying Methods 0.000 claims description 7
- 239000003349 gelling agent Substances 0.000 claims description 7
- 150000003839 salts Chemical class 0.000 claims description 7
- 229910052681 coesite Inorganic materials 0.000 claims description 5
- 229910052906 cristobalite Inorganic materials 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 229910052682 stishovite Inorganic materials 0.000 claims description 5
- 229910052905 tridymite Inorganic materials 0.000 claims description 5
- -1 calcium cations Chemical class 0.000 claims description 4
- 239000011159 matrix material Substances 0.000 claims description 4
- 238000001556 precipitation Methods 0.000 claims description 4
- 229910052910 alkali metal silicate Inorganic materials 0.000 claims description 3
- 238000011010 flushing procedure Methods 0.000 claims description 3
- 230000002028 premature Effects 0.000 claims description 3
- 239000011398 Portland cement Substances 0.000 claims description 2
- 238000001879 gelation Methods 0.000 claims description 2
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 claims description 2
- 229940074415 potassium silicate Drugs 0.000 claims 32
- CHWRSCGUEQEHOH-UHFFFAOYSA-N potassium oxide Chemical compound [O-2].[K+].[K+] CHWRSCGUEQEHOH-UHFFFAOYSA-N 0.000 claims 6
- 229910001950 potassium oxide Inorganic materials 0.000 claims 6
- 238000005189 flocculation Methods 0.000 claims 1
- 230000016615 flocculation Effects 0.000 claims 1
- 229910001948 sodium oxide Inorganic materials 0.000 claims 1
- 230000018044 dehydration Effects 0.000 description 10
- 238000006297 dehydration reaction Methods 0.000 description 10
- 239000000499 gel Substances 0.000 description 10
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 8
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 8
- 230000035515 penetration Effects 0.000 description 8
- 208000005156 Dehydration Diseases 0.000 description 7
- 239000003795 chemical substances by application Substances 0.000 description 7
- 239000007788 liquid Substances 0.000 description 7
- 239000002002 slurry Substances 0.000 description 7
- 238000001694 spray drying Methods 0.000 description 7
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 235000019351 sodium silicates Nutrition 0.000 description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 5
- 238000005553 drilling Methods 0.000 description 5
- 238000003860 storage Methods 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 239000003513 alkali Substances 0.000 description 4
- 230000004087 circulation Effects 0.000 description 4
- 238000011109 contamination Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000006703 hydration reaction Methods 0.000 description 4
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 230000002829 reductive effect Effects 0.000 description 4
- 230000008719 thickening Effects 0.000 description 4
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000013535 sea water Substances 0.000 description 3
- 239000003352 sequestering agent Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 206010016803 Fluid overload Diseases 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000008186 active pharmaceutical agent Substances 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000003518 caustics Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 239000013505 freshwater Substances 0.000 description 2
- 230000036571 hydration Effects 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000008399 tap water Substances 0.000 description 2
- 235000020679 tap water Nutrition 0.000 description 2
- 230000003313 weakening effect Effects 0.000 description 2
- POAOYUHQDCAZBD-UHFFFAOYSA-N 2-butoxyethanol Chemical compound CCCCOCCO POAOYUHQDCAZBD-UHFFFAOYSA-N 0.000 description 1
- 239000010755 BS 2869 Class G Substances 0.000 description 1
- 241000237858 Gastropoda Species 0.000 description 1
- 240000007930 Oxalis acetosella Species 0.000 description 1
- 235000008098 Oxalis acetosella Nutrition 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000006172 buffering agent Substances 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- 239000000306 component Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000002716 delivery method Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- PEVUYKOFPBOCRF-UHFFFAOYSA-N dipotassium dioxosilane oxygen(2-) Chemical compound [Si](=O)=O.[O-2].[K+].[K+] PEVUYKOFPBOCRF-UHFFFAOYSA-N 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 159000000003 magnesium salts Chemical class 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- BITYAPCSNKJESK-UHFFFAOYSA-N potassiosodium Chemical compound [Na].[K] BITYAPCSNKJESK-UHFFFAOYSA-N 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000000246 remedial effect Effects 0.000 description 1
- 229910052701 rubidium Inorganic materials 0.000 description 1
- IGLNJRXAVVLDKE-UHFFFAOYSA-N rubidium atom Chemical compound [Rb] IGLNJRXAVVLDKE-UHFFFAOYSA-N 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/04—Aqueous well-drilling compositions
- C09K8/14—Clay-containing compositions
- C09K8/145—Clay-containing compositions characterised by the composition of the clay
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/32—Alkali metal silicates
- C01B33/325—After-treatment, e.g. purification or stabilisation of solutions, granulation; Dissolution; Obtaining solid silicate, e.g. from a solution by spray-drying, flashing off water or adding a coagulant
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B12/00—Cements not provided for in groups C04B7/00 - C04B11/00
- C04B12/04—Alkali metal or ammonium silicate cements ; Alkyl silicate cements; Silica sol cements; Soluble silicate cements
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/42—Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/5045—Compositions based on water or polar solvents containing inorganic compounds
Abstract
Abstract of the Disclosure Rapidly dissolvable powdered silicates having a molar ratio of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1 wherein the alkali metal is selected from the group consisting of sodium, potassium and mixtures thereof. Methods of using the powdered silicates and resulting solutions in connection with sealing and cementing, especially of well formations, are provided.
Description
~o~
RAPII~)LY DISSOLVABLE SILICATES
AND METHODS OF USING TOE SAME
_ _ In the drilling, completion and remedial treatment of oil, gas and water wells, it is often desirable and necessary to seal earth formation zones in the wells to prevent excessive fluid flow or loss in the zones, to divert fluids from one zone to another, and to accomplish other purposes. In addition, in such well operations, it is often necessary or desirable to cement casing or other apparatus in the well bore. For example, it is common practice in sealing well formations -to inject cement into -the well and to allow the cement to set in the desired location to seal this portion of the well. Also, when fixing casing in the well, the casing is cemented to the formation to retain the casing .in place ancl to seal the production formation from -the remaining formations.
A particular problem in using cement for the sealing of earth formations is that cement often cannot penetrate to a de-sired location through the formation matrix. Therefore, gelable liquids have been used to provide the pene-tration required. While many different gelable liquids have been used, gelable aqueous sodium silicate solutions have achieved wide acceptance. In utilizing aqueous sodium silicate solutions to seal earth forma-tions, the sodium silicate can be combined with acid forming or buffering agents to produce fluids with specific gel times. The silicate-agent solutions are injected into the formations and allowed to set whereby the resulting firm impermeable masses seal the formations.
'I
~z~
Aqueous sodium silicate solutions have also been used to seal earth formations wherein the sodium silieate solutions are caused to gel by contact with a separate gelling agent or catalyst.
For example, an acid solution can be introdueed into the formation prior to or after the introduetion of the sodium silieate solution.
Upon the contaet of the sodium silicate solution with the aeid solution, gelling occurs producing an impermeable mass which seals the formation. Solutions containing ealeium or other polyvalent eations are also suitable as gelling agen-ts.
Sodium silieate solutions have also been used in low eoneen-trations to seal more permeable portions of formations undergoing water Elooding. In this applieatlon, a sodlum slliea-te solution is added -to the flood water so that as the sodium silicate con-tacts ealeium in the more permeable zones in the formation as it flows through sueh zones, it floeulates thereby plugging the more permeable zones and diverting flood water to other less permeable zones, thereby inereasing the production of oil therefrom.
In utilizing aqueous sodium silicate solutions for sealing earth formations, aqueous solutions of sodium silicate are trans-ported to the location of a well penetrating the formation in aeoncen-trated form (typically, ~0% sodium silicate). This concen-trated sodium silieate solu-tion is then mixed with water at the well site -to produce the injeeted fluid. A partieular problem with this method is that the aqueous solutions ean freeze during transport or ln storage at the well slte thereby ruining the silicate solution. Also, such concentrated aqueous solutions are extremely caus-tic and, like all caustic liquids, are diffi-cult to handle and mix. Further, the handling and shipping of the concentrated aqueous solutions of sodium silicate are expensive, especially in offshore drilling and remote loca-tions where storage is limited.
Another problem in the use of aqueous sodium silicate solu-tions for sealing earth formations is that sodium silicate is extremely sensitive -to certain materials found in some ear-th for-mations and in some rnixing liquids. For example, formations containing di- or polyvalent cations such as calcium can produce fl~sh-gelling or floculltlon ox the sodium silicate solutions preventing penetration of the solutions to proper locations.
Similary, sodium silicate solutions cannot be mixed with brines because premature gelling occurs.
In cementing casing to the well bore it has often been found that preflushes pumped ahead of the cement to prepare the well bore for cementing can damage the surface of the well bore. For example, preflushes -through anhydrite formations often dissolve the formation expanding the diameter of the well bore and weakening the zones in which the cement-to-formation bond occurs. To seal the formation against this type of deterioration, sodium silicate solutions have been introduced into the preflush. This method, however, is not completely satisfactory since good cement bonding is still not achieved in certain situations. Particularly, sodium silicate solutions floculate when they encounter sodiurn chloride salts of the type present in anhydrite formations. Consequently, sodium silicate solutions are not able to fully protect formations from dissolving and weakening because floculation prevents pene-tration of the silicate into the formations and the silicate canbe lost through redissolution.
Another problem with using sodium silicate as a preflush in cementing is -that the cement-carrying conduits contain residual amounts of calcium despite efforts to clean the conduits. This residual calcium which contaminates the conduits can prematurely cause gelling or floculation of the sodium silicate so:Lution which prevents the sodiurn silicate from functioning properLy.
Another use of aqueous sodium silicate solutions is as a dispersant and a gelling agent in a wet cement mix-ture. By adding a sodium silicate solution to the cement mixture as it is mixed, the cement is more evenly dispersed. If the concentration of the sodium silicate in the cement mixture is high enough, the setting time of the cemen-t mixture is reduced. As with the other uses of sodium silicate solutions described above, problems are encountered with storage and handling of concentrated aqueous sodium silicate solutions. The sodium silica-te solutions can also gel prematurely when the cement powder is added, making mixing difficult.
By the present invention, a rapidly dissolvable powdered silicate is provided. the powdered silicate not only is rapidly dissolvable but also has a high ratio of silicon dioxide to ,7~
alkall metal oxide making it usable in sealing and cementing methods. By means of the powdered silicate, silicate solutions and silicate mixtures for use at well sites can be prepared rapidly. Further, the powdered silicate of the present invention is easily transported and stored even in low temperature condi-tions which would freeze and destroy aqueous silicate solutions.
The costs of handling and transporting -the silica-te are reduced since the powder weighs less and has a lower volume.
The rapidly dissolvable powdered silicate of the present invention useful in the methods described herein has a ratio of silicon dioxide to alkali metal oxide in the range of from abou-t 1.5:1 to about 3.3:1. To improve the gelliny ability, strenyth and concentration oE the sillcon dioxide which gels from -the silicate solution, it is desirable -to have a high ratio of silicon dioxide to alkali metal oxide. Such high ratio also reduces the amount of alkali metal oxide which must be neutralized to pro-duce gelling. However, higher ratios are generally more difficult to dissolve. Therefore, it is preferable -to maintain the ratio of silicon dioxide -to alkali me-tal oxide in the range of from about 2.0:1 to about 2.7:1. Most preferably, the ratio of silicon dioxide to alkali me-tal oxide is maintained at a ratio of abou-t
RAPII~)LY DISSOLVABLE SILICATES
AND METHODS OF USING TOE SAME
_ _ In the drilling, completion and remedial treatment of oil, gas and water wells, it is often desirable and necessary to seal earth formation zones in the wells to prevent excessive fluid flow or loss in the zones, to divert fluids from one zone to another, and to accomplish other purposes. In addition, in such well operations, it is often necessary or desirable to cement casing or other apparatus in the well bore. For example, it is common practice in sealing well formations -to inject cement into -the well and to allow the cement to set in the desired location to seal this portion of the well. Also, when fixing casing in the well, the casing is cemented to the formation to retain the casing .in place ancl to seal the production formation from -the remaining formations.
A particular problem in using cement for the sealing of earth formations is that cement often cannot penetrate to a de-sired location through the formation matrix. Therefore, gelable liquids have been used to provide the pene-tration required. While many different gelable liquids have been used, gelable aqueous sodium silicate solutions have achieved wide acceptance. In utilizing aqueous sodium silicate solutions to seal earth forma-tions, the sodium silicate can be combined with acid forming or buffering agents to produce fluids with specific gel times. The silicate-agent solutions are injected into the formations and allowed to set whereby the resulting firm impermeable masses seal the formations.
'I
~z~
Aqueous sodium silicate solutions have also been used to seal earth formations wherein the sodium silieate solutions are caused to gel by contact with a separate gelling agent or catalyst.
For example, an acid solution can be introdueed into the formation prior to or after the introduetion of the sodium silieate solution.
Upon the contaet of the sodium silicate solution with the aeid solution, gelling occurs producing an impermeable mass which seals the formation. Solutions containing ealeium or other polyvalent eations are also suitable as gelling agen-ts.
Sodium silieate solutions have also been used in low eoneen-trations to seal more permeable portions of formations undergoing water Elooding. In this applieatlon, a sodlum slliea-te solution is added -to the flood water so that as the sodium silicate con-tacts ealeium in the more permeable zones in the formation as it flows through sueh zones, it floeulates thereby plugging the more permeable zones and diverting flood water to other less permeable zones, thereby inereasing the production of oil therefrom.
In utilizing aqueous sodium silicate solutions for sealing earth formations, aqueous solutions of sodium silicate are trans-ported to the location of a well penetrating the formation in aeoncen-trated form (typically, ~0% sodium silicate). This concen-trated sodium silieate solu-tion is then mixed with water at the well site -to produce the injeeted fluid. A partieular problem with this method is that the aqueous solutions ean freeze during transport or ln storage at the well slte thereby ruining the silicate solution. Also, such concentrated aqueous solutions are extremely caus-tic and, like all caustic liquids, are diffi-cult to handle and mix. Further, the handling and shipping of the concentrated aqueous solutions of sodium silicate are expensive, especially in offshore drilling and remote loca-tions where storage is limited.
Another problem in the use of aqueous sodium silicate solu-tions for sealing earth formations is that sodium silicate is extremely sensitive -to certain materials found in some ear-th for-mations and in some rnixing liquids. For example, formations containing di- or polyvalent cations such as calcium can produce fl~sh-gelling or floculltlon ox the sodium silicate solutions preventing penetration of the solutions to proper locations.
Similary, sodium silicate solutions cannot be mixed with brines because premature gelling occurs.
In cementing casing to the well bore it has often been found that preflushes pumped ahead of the cement to prepare the well bore for cementing can damage the surface of the well bore. For example, preflushes -through anhydrite formations often dissolve the formation expanding the diameter of the well bore and weakening the zones in which the cement-to-formation bond occurs. To seal the formation against this type of deterioration, sodium silicate solutions have been introduced into the preflush. This method, however, is not completely satisfactory since good cement bonding is still not achieved in certain situations. Particularly, sodium silicate solutions floculate when they encounter sodiurn chloride salts of the type present in anhydrite formations. Consequently, sodium silicate solutions are not able to fully protect formations from dissolving and weakening because floculation prevents pene-tration of the silicate into the formations and the silicate canbe lost through redissolution.
Another problem with using sodium silicate as a preflush in cementing is -that the cement-carrying conduits contain residual amounts of calcium despite efforts to clean the conduits. This residual calcium which contaminates the conduits can prematurely cause gelling or floculation of the sodium silicate so:Lution which prevents the sodiurn silicate from functioning properLy.
Another use of aqueous sodium silicate solutions is as a dispersant and a gelling agent in a wet cement mix-ture. By adding a sodium silicate solution to the cement mixture as it is mixed, the cement is more evenly dispersed. If the concentration of the sodium silicate in the cement mixture is high enough, the setting time of the cemen-t mixture is reduced. As with the other uses of sodium silicate solutions described above, problems are encountered with storage and handling of concentrated aqueous sodium silicate solutions. The sodium silica-te solutions can also gel prematurely when the cement powder is added, making mixing difficult.
By the present invention, a rapidly dissolvable powdered silicate is provided. the powdered silicate not only is rapidly dissolvable but also has a high ratio of silicon dioxide to ,7~
alkall metal oxide making it usable in sealing and cementing methods. By means of the powdered silicate, silicate solutions and silicate mixtures for use at well sites can be prepared rapidly. Further, the powdered silicate of the present invention is easily transported and stored even in low temperature condi-tions which would freeze and destroy aqueous silicate solutions.
The costs of handling and transporting -the silica-te are reduced since the powder weighs less and has a lower volume.
The rapidly dissolvable powdered silicate of the present invention useful in the methods described herein has a ratio of silicon dioxide to alkali metal oxide in the range of from abou-t 1.5:1 to about 3.3:1. To improve the gelliny ability, strenyth and concentration oE the sillcon dioxide which gels from -the silicate solution, it is desirable -to have a high ratio of silicon dioxide to alkali metal oxide. Such high ratio also reduces the amount of alkali metal oxide which must be neutralized to pro-duce gelling. However, higher ratios are generally more difficult to dissolve. Therefore, it is preferable -to maintain the ratio of silicon dioxide -to alkali me-tal oxide in the range of from about 2.0:1 to about 2.7:1. Most preferably, the ratio of silicon dioxide to alkali me-tal oxide is maintained at a ratio of abou-t
2.5:1. Silicates of such ratio have short dissolution times while still having relatively high silicon dioxide densities. Some methods of making the powdered silicate can produce hiyher ratios, while still maintaining short solubility times. In many cases, however, these methods are uneconomical.
In the past, anhydrous powdered silicates have been commer-cially available with ratios of silicon dioxide to alkali metal oxide in -the range of from about 1.5:1 to about 4.0:1. However, these silicates have not been,easily dissolvable regardless of the par-ticle size. Therefore, powdered silicates have not been utilized to prepare aqueous solutions of silicates for sealing earth formations.
As described above, the ability to dissolve alkali metal silicates decreases as -the ratio of silicon dioxide to alkali metal oxide increases. Thus, some powdered silicates having very low (less than 1.5:1) ratlos of silicon dioxide to alkali metal oxide have been prepared for forming aqueous silicate solutions. These, however, have not been suitable for use in connection with wells or sealing earth formations because the solu-tions are overly alkaline and are not easily gelled.
In order to be rapidly dissolvable, the powdered silicate is preferably partially hydrated. Over-hydration or under-hydration, however, produces an unsatisfactory powder. Over-hydration (more than about 20~ water content by weight) producesamorphous particles which -tend to flow and slowly convert to crystalline silicate which is slowly soluble. Under-hydration (less than about 12~ water content by weight) results in particles which are crystalline initially and, -therefore, are not dis-solvable. Most preferably, the partially hydrated powdered .
silicate of the present invention has a water content in the range of from about 14% to abou-t 16% by weight of the hydrated silicate. Amorphous particles with this hydration are relatively stable and are easily dissolved.
The powdered silicate of the present invention is comprised of amorphous par-ticles of the partially hydrated silicate. Crys-talline particles are not readily dissolvable.
In the powdered silicates of the present invention, either sodium or po-tassium or mixtures thereof can be utilized as the alkali metal in the silicate. The powdered silicate of -the pre-sent invention can be represented by the formula SiO2:M2O. As stated above, is selected from the yroup consis-tiny of soclium, potassium and mixtures thereof. Other alkali me-tals, such as lithium and rubidium are not suitable because of their signifi-cantly different properties. As will be discussed hereinbelow, sodium silicates and potassium silicates have different properties and potassium silicates or mixtures of potassium silicates are more suitable for particular applications.
In the preparation of the rapidly dissolvable powdered sili-cate of the present invention, dehydration by heating a solu-tion of appropriate silicon dioxide-alkali metal oxide ratio is not suit-able. Dehydration by heating or boiling of such a solution pro-duces a stable silicate which is only very slowly soluble.
To produce a rapidly dissolvable powdered silicate, two methods are appropriate. The first method consists of spray drying a silicate solution having a temperature less than 100F.
The spray drying produces a powder of amorphous glass particles.
Furthermore, it allows production of a partially hydrated powdered silicate having a water content in the range of from about 14%
S to about 16% by weight of the hydrated silicate. As stated above, this range of partial~hydration and the amorphous glass quality of the particles have a significant effect upon the ability of the silicate to dissolve.
In producing the powdered silicate by spray drying, a sili-0 cate solution having a desired ratio of sllicon dioxide to alkalimetal oxide in the range of from about 1.5:1 -to about 3.3:1 is prepared and m.l:Lntained at a tcrnE)erature lower than 110F and preferably lower than 85E`. This solution is delivered to a spray drying device which produces rapid cooling and rapid dehy-L5 dration of small droplets of -the solution. In the process of rapidly cooling and dehydrating, the droplets pass from an equili-brium to a non-equilibrium state such that an easily soluble amor-phous glass particle is formed. The cooling and dehydration must be rapid enough to prevent the silica-te from being converted to a slowly soluble crystal state. If necessary, the solution can be refrigerated and the spray directed against a cooled baffle or the like.
The second method of preparing the rapidly dissolvable pow-dered silicate also utilizes rapid dehydration at a relatively low temperature. In this method, however, dehydration is achieved by acdding a dehydration agent to the silicate solution of the appropriate ratio. During the dehydration, the solution must be maintained at a temperature less than 110F and preferably less than 85F. Furthermore, to avoid crystallization and agglomera-tion of some of the amorphous particles, it is necessary to rapidly shear the solution as the dehydration agent is added.
Preferred dehydration agents include ethanol, methanol and acetone.
Less suitable are isopropyl alcohol, butyl alcohol, and ethylene glycol monobutyl ether. Also less suitable are saturated salt solutions such as those of sodium chloride and potassium chloricle.
As a dehydra-tion agent such as e-thanol is added -to the silicate solution undergoing rapid shearlng, part:icles Oe par-tially hydrated amorphous silica-te are precipitated from the silicate solution. These particles are separated from the liquid and then dried without heating. For example, additional alcohol can be added to the particles and then allowed to evaporate at room temperature.
In either the spray drying or precipitation me-thods, trace amounts of lithium and copper can be added to help prevent crys-tallization of the silicates. Li-thium provides an undersized atomic particle and copper provides an oversized atomic particle to assist in breaking up crystalline patterns as they form.
Other suitable undersized or oversized atomic particles can be utilized.
In order to be rapidly dissolvable, it is desirable to have the amorphous particles of the powdered silicate smaller than 40-mesh size. If a significant number, 10% for example, of par-ticles are larger than ~0-mesh size, the solu-tion time is suffi-ciently long that field use is hampered. To arrive at a powder having less than 40-mesh size, the powder resulting from the preparation methods can be screened or ground until the appro-priate size is achieved. Also, the particle size can be controlled in the formation process of spray drying or precipitation with methods that are well-known.
0 By utilizing the powdered silicate of the present invention, an improved method of preparing an aqueous silicate solution for use in connection with sealing or cementing earth formations at a well site can be achieved. In such method oE preparing an aqueous silicate solution, the rapidly dissolvable partially hy-drated powdered silicate is prepared having a molar ra-tlo of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1. The powdered silicate is then transported to the well location and dissolved to form an aqueous silicate solution. The resulting solu-tion is used in processes of sealing ~0 or cementing. If desired, the powdered silicate can be stored at the well location prior to its use. Furthermore, the storage can occur at temperatures below freezing without adverse effect to the powdered silicate material.
In some situations, the only water available at well loca-tions contains salt. Thus, it is desirable to be able to form a silicate solution by mixing the powdered silica-te with brine.
While sodium silicatés tend to gel prematurely when mixed with brine, partially hydrated potassium silicates do not. Therefore, it is desirable to utilize a partially hydrated powdered silicate consisting essentially of potassium silicate when the aqueous solution is to be prepared with brine. The potassium silicate does not gel prematurely upon mixing with the brine. If, however, the salt concentration of the brine is very high/ especially with calcium or magnesium salts, or the resulting solution is to be stored more than -three or four hours, it is desirable to add a sequestering agent to the solution. Organo-phosphates are suit-able sequestering agents. Wi-th the addition of such a sequestering gent, the solutlon can be stored for several days.
While potassium silica-te solutions are less reactive with sodium, calcium, and other di- and polyvalent ions than sodium silicate solutions, gelling still results upon combination with a sufficient amount of these agents or a sufficient amount of reac-tion time. The slower gelling time and higher concentration of gelling agent or catalyst can, therefore, be utilized to produce gelling at a desired tLme or location where sodium silicate would not be suitable. For example, in earth formations containing sodium, calcium and/or di- and polyvalent ions (anhydrite earth formations, for example), a potassium silicate can be utilized where a sodium silicate would floculate prematurely without suf-ficient penetration of the formation. In one useful process, a potassium silicate solution is prepared which will gel whencombined with the di- or polyvalent cations or salts of the type in the earth formation and will penetrate the formation without premature floculation. The amount of penetration can be varied by chanyiny the acidity of the po-tassium silicate solution, changing the silicon dioxide potassium oxide ratio, or adding sequestering agents to the solution. Of course, the proper solution will depend upon -the -type and concentration of reactant ions pre-sent in the earth formation. After the potassium silicate solu-tion is prepared using the highly dissolvable, partially hydrated,powdered, amorphous potassium silica-te of the presen-t invention, the silicate solution is introduced into the ear-th formation and allowed to gel thereby selling the formation.
my utilizing the same di or polyvalent cations or salts in an injection fluid, the potassium silicate solution can be used in a method whereby alternate slugs of the injection fluid and the potassium silicate solution are introduced to the well forma-tion for sealing. This method is useful for sealing vugular, matrix or channel type earth formations. This alternate intro-duction of the po-tassium silica-te solution and the injection fluid con-taining cations which gel the solu-tion into the formation produces gelling of the potassium silicate solution at a desired location. As descried above, the potassium silicate solutions are less reactive with the injection fluid containing gelling agents and therefore allow a deeper penetration of the formation.
~2~
Since Portland type cements contain di- or polyvalent cations, e.g., calcium cations, a use of the above method is to utilize Portland cement as the gelling agent fluid. Because the cement will penetrate the vugular and larger channel portions of the formatlon and then set sealing those portions, a particularly desirable result is obtained. Another fluid containing di- or polyvalent cations is brine. Since brine is often the only readily available fluid at well formation locations and brine is often not capable of being used with sodium silicates, the use of potassium silicate in accordance with the method of this invention allows brine to be used in forming and using silicate solutions.
Another particularly advantacJeous use of the rapicl.Ly dis-solvable powdered silicate of the present invention is as a com-ponent of a cement powder. A mixture of Portland cemen-t and the lS rapidly dissolvable powdered silicate of the present invention produces a cement powder which has improved properties. Upon mixiny, the cement is more evenly dispersed with a water mixture.
By varying the concentration of the powdered silicate in the cement powder, the setting time of -the cement can be either in-creased or decreased. also, the powdered silica-te increases the strength of the cement at high temperatures and creates a tem-perature stable cemen-t. In addition, it increases the water:
cement ratio.
Particularly useful as an additive to cement is potassium sllica-te powder. Potassium slllcate ls less sensltlve to 7~
contamina-tion of -the cement and allows the cement to penetrate further into salt containing formations. If desired, similar advantages can be achieved by adding potassium silicate to the mixing water in mixing the cement slurry.
While many of -the above methods of using the powdered sili-cate of the present invention are particularly adapted for use wi-th potassium silicate, many processes can advantageously use combinations of potassium silicate and sodium silicate. This allows the differing properties of the silicates to be utilized and combined in a single powder or application. Thus, mixtures of potassium and sodium silicates can be used to vary -the gelliny time or the duration of yelling in various applications. Since sodlum silicates are less expensive than potassium silicates, mix--tures also allow the cost of the silicate use to be reduced.
Another particularly suitable use for potassium silicate as opposed to sodium silicate solutions is as a preflush for cement-ing casing to a well bore. Particularly in situations where the well bore extends -through anhydrite earth formations, sodium silicate preflushes are no-t completely satisfactory since -they tend to flocula-te upon contact with a sufficient concen-tration of sodium in the earth formation. Accordingly, flushing the ear-th formation with an aqueous solution of potassium silicate allows penetration of -the formation by the potassium silicate which is more slowly jelled by calcium in the formation, by gelling agents circulated ahead of or with the cement, or other methods. This gelled penetration of the formation pro-tects the formation from deterioration during preflush and prepares the formation for bonding with the cement which follows.
In order to facilita-te a clear understancLing of the silicate compositions and me-thods of the present invention, the following examples are given.
Example 1 600 cc of acetone and 300 cc of a 40 Baumé, 3.32 ratio sodium silicate solution (Diamond Shamrock "grade 40" sodium silicate) are combined in a Waring blender at low speed. The speed of the blender is turned up to high to insure di.ssolution since the silicate solution instantaneously dehydrates. The resulting precipitate is filtered, washed wi-th additional acetone and allowed to dry overnight without heating. All of the fore-going is conducted at room temperature.
After drying overnight, the precipitate is brushed from the drying surface and redlssolved in water to its original solubility.
The solution is complete within 3 minute's. The above experiment is also performed wi-th -the same results utilizing ethanol and methanol as subs-titutes for the acetone and po-tassium silicate as a substitute for the sodium silicate. Drying more rapidly at 100F creates a material which is more easily dissolved.
The foregoing shows that rapidly dissolvable partially hydrated amorphous powdered silicates with high ratios can be 4 f prepared. ~lowever, this is a relatively expensive process.
Example 2 Powdered silicates are prepared by spray drying aqueous silicate solutions at room temperature. The molar ratios of the silicates vary from 1.8 to 3.2. Both sodium silicates and potas-sium silica-tes are prepared. The resulting powders are -tested for solubility, the results of which are shown in Table I below.
TABLE I - SOL~BILITY OF POWDERED SILICATES
Mole Ratio of Solubility Silicate/Alkali - - Na2O K2O
___ 1.8 S --2.0 SS --2.2 NS S
2.4 NS S
2.6 NS SS
2.8 NS NS
In the past, anhydrous powdered silicates have been commer-cially available with ratios of silicon dioxide to alkali metal oxide in -the range of from about 1.5:1 to about 4.0:1. However, these silicates have not been,easily dissolvable regardless of the par-ticle size. Therefore, powdered silicates have not been utilized to prepare aqueous solutions of silicates for sealing earth formations.
As described above, the ability to dissolve alkali metal silicates decreases as -the ratio of silicon dioxide to alkali metal oxide increases. Thus, some powdered silicates having very low (less than 1.5:1) ratlos of silicon dioxide to alkali metal oxide have been prepared for forming aqueous silicate solutions. These, however, have not been suitable for use in connection with wells or sealing earth formations because the solu-tions are overly alkaline and are not easily gelled.
In order to be rapidly dissolvable, the powdered silicate is preferably partially hydrated. Over-hydration or under-hydration, however, produces an unsatisfactory powder. Over-hydration (more than about 20~ water content by weight) producesamorphous particles which -tend to flow and slowly convert to crystalline silicate which is slowly soluble. Under-hydration (less than about 12~ water content by weight) results in particles which are crystalline initially and, -therefore, are not dis-solvable. Most preferably, the partially hydrated powdered .
silicate of the present invention has a water content in the range of from about 14% to abou-t 16% by weight of the hydrated silicate. Amorphous particles with this hydration are relatively stable and are easily dissolved.
The powdered silicate of the present invention is comprised of amorphous par-ticles of the partially hydrated silicate. Crys-talline particles are not readily dissolvable.
In the powdered silicates of the present invention, either sodium or po-tassium or mixtures thereof can be utilized as the alkali metal in the silicate. The powdered silicate of -the pre-sent invention can be represented by the formula SiO2:M2O. As stated above, is selected from the yroup consis-tiny of soclium, potassium and mixtures thereof. Other alkali me-tals, such as lithium and rubidium are not suitable because of their signifi-cantly different properties. As will be discussed hereinbelow, sodium silicates and potassium silicates have different properties and potassium silicates or mixtures of potassium silicates are more suitable for particular applications.
In the preparation of the rapidly dissolvable powdered sili-cate of the present invention, dehydration by heating a solu-tion of appropriate silicon dioxide-alkali metal oxide ratio is not suit-able. Dehydration by heating or boiling of such a solution pro-duces a stable silicate which is only very slowly soluble.
To produce a rapidly dissolvable powdered silicate, two methods are appropriate. The first method consists of spray drying a silicate solution having a temperature less than 100F.
The spray drying produces a powder of amorphous glass particles.
Furthermore, it allows production of a partially hydrated powdered silicate having a water content in the range of from about 14%
S to about 16% by weight of the hydrated silicate. As stated above, this range of partial~hydration and the amorphous glass quality of the particles have a significant effect upon the ability of the silicate to dissolve.
In producing the powdered silicate by spray drying, a sili-0 cate solution having a desired ratio of sllicon dioxide to alkalimetal oxide in the range of from about 1.5:1 -to about 3.3:1 is prepared and m.l:Lntained at a tcrnE)erature lower than 110F and preferably lower than 85E`. This solution is delivered to a spray drying device which produces rapid cooling and rapid dehy-L5 dration of small droplets of -the solution. In the process of rapidly cooling and dehydrating, the droplets pass from an equili-brium to a non-equilibrium state such that an easily soluble amor-phous glass particle is formed. The cooling and dehydration must be rapid enough to prevent the silica-te from being converted to a slowly soluble crystal state. If necessary, the solution can be refrigerated and the spray directed against a cooled baffle or the like.
The second method of preparing the rapidly dissolvable pow-dered silicate also utilizes rapid dehydration at a relatively low temperature. In this method, however, dehydration is achieved by acdding a dehydration agent to the silicate solution of the appropriate ratio. During the dehydration, the solution must be maintained at a temperature less than 110F and preferably less than 85F. Furthermore, to avoid crystallization and agglomera-tion of some of the amorphous particles, it is necessary to rapidly shear the solution as the dehydration agent is added.
Preferred dehydration agents include ethanol, methanol and acetone.
Less suitable are isopropyl alcohol, butyl alcohol, and ethylene glycol monobutyl ether. Also less suitable are saturated salt solutions such as those of sodium chloride and potassium chloricle.
As a dehydra-tion agent such as e-thanol is added -to the silicate solution undergoing rapid shearlng, part:icles Oe par-tially hydrated amorphous silica-te are precipitated from the silicate solution. These particles are separated from the liquid and then dried without heating. For example, additional alcohol can be added to the particles and then allowed to evaporate at room temperature.
In either the spray drying or precipitation me-thods, trace amounts of lithium and copper can be added to help prevent crys-tallization of the silicates. Li-thium provides an undersized atomic particle and copper provides an oversized atomic particle to assist in breaking up crystalline patterns as they form.
Other suitable undersized or oversized atomic particles can be utilized.
In order to be rapidly dissolvable, it is desirable to have the amorphous particles of the powdered silicate smaller than 40-mesh size. If a significant number, 10% for example, of par-ticles are larger than ~0-mesh size, the solu-tion time is suffi-ciently long that field use is hampered. To arrive at a powder having less than 40-mesh size, the powder resulting from the preparation methods can be screened or ground until the appro-priate size is achieved. Also, the particle size can be controlled in the formation process of spray drying or precipitation with methods that are well-known.
0 By utilizing the powdered silicate of the present invention, an improved method of preparing an aqueous silicate solution for use in connection with sealing or cementing earth formations at a well site can be achieved. In such method oE preparing an aqueous silicate solution, the rapidly dissolvable partially hy-drated powdered silicate is prepared having a molar ra-tlo of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1. The powdered silicate is then transported to the well location and dissolved to form an aqueous silicate solution. The resulting solu-tion is used in processes of sealing ~0 or cementing. If desired, the powdered silicate can be stored at the well location prior to its use. Furthermore, the storage can occur at temperatures below freezing without adverse effect to the powdered silicate material.
In some situations, the only water available at well loca-tions contains salt. Thus, it is desirable to be able to form a silicate solution by mixing the powdered silica-te with brine.
While sodium silicatés tend to gel prematurely when mixed with brine, partially hydrated potassium silicates do not. Therefore, it is desirable to utilize a partially hydrated powdered silicate consisting essentially of potassium silicate when the aqueous solution is to be prepared with brine. The potassium silicate does not gel prematurely upon mixing with the brine. If, however, the salt concentration of the brine is very high/ especially with calcium or magnesium salts, or the resulting solution is to be stored more than -three or four hours, it is desirable to add a sequestering agent to the solution. Organo-phosphates are suit-able sequestering agents. Wi-th the addition of such a sequestering gent, the solutlon can be stored for several days.
While potassium silica-te solutions are less reactive with sodium, calcium, and other di- and polyvalent ions than sodium silicate solutions, gelling still results upon combination with a sufficient amount of these agents or a sufficient amount of reac-tion time. The slower gelling time and higher concentration of gelling agent or catalyst can, therefore, be utilized to produce gelling at a desired tLme or location where sodium silicate would not be suitable. For example, in earth formations containing sodium, calcium and/or di- and polyvalent ions (anhydrite earth formations, for example), a potassium silicate can be utilized where a sodium silicate would floculate prematurely without suf-ficient penetration of the formation. In one useful process, a potassium silicate solution is prepared which will gel whencombined with the di- or polyvalent cations or salts of the type in the earth formation and will penetrate the formation without premature floculation. The amount of penetration can be varied by chanyiny the acidity of the po-tassium silicate solution, changing the silicon dioxide potassium oxide ratio, or adding sequestering agents to the solution. Of course, the proper solution will depend upon -the -type and concentration of reactant ions pre-sent in the earth formation. After the potassium silicate solu-tion is prepared using the highly dissolvable, partially hydrated,powdered, amorphous potassium silica-te of the presen-t invention, the silicate solution is introduced into the ear-th formation and allowed to gel thereby selling the formation.
my utilizing the same di or polyvalent cations or salts in an injection fluid, the potassium silicate solution can be used in a method whereby alternate slugs of the injection fluid and the potassium silicate solution are introduced to the well forma-tion for sealing. This method is useful for sealing vugular, matrix or channel type earth formations. This alternate intro-duction of the po-tassium silica-te solution and the injection fluid con-taining cations which gel the solu-tion into the formation produces gelling of the potassium silicate solution at a desired location. As descried above, the potassium silicate solutions are less reactive with the injection fluid containing gelling agents and therefore allow a deeper penetration of the formation.
~2~
Since Portland type cements contain di- or polyvalent cations, e.g., calcium cations, a use of the above method is to utilize Portland cement as the gelling agent fluid. Because the cement will penetrate the vugular and larger channel portions of the formatlon and then set sealing those portions, a particularly desirable result is obtained. Another fluid containing di- or polyvalent cations is brine. Since brine is often the only readily available fluid at well formation locations and brine is often not capable of being used with sodium silicates, the use of potassium silicate in accordance with the method of this invention allows brine to be used in forming and using silicate solutions.
Another particularly advantacJeous use of the rapicl.Ly dis-solvable powdered silicate of the present invention is as a com-ponent of a cement powder. A mixture of Portland cemen-t and the lS rapidly dissolvable powdered silicate of the present invention produces a cement powder which has improved properties. Upon mixiny, the cement is more evenly dispersed with a water mixture.
By varying the concentration of the powdered silicate in the cement powder, the setting time of -the cement can be either in-creased or decreased. also, the powdered silica-te increases the strength of the cement at high temperatures and creates a tem-perature stable cemen-t. In addition, it increases the water:
cement ratio.
Particularly useful as an additive to cement is potassium sllica-te powder. Potassium slllcate ls less sensltlve to 7~
contamina-tion of -the cement and allows the cement to penetrate further into salt containing formations. If desired, similar advantages can be achieved by adding potassium silicate to the mixing water in mixing the cement slurry.
While many of -the above methods of using the powdered sili-cate of the present invention are particularly adapted for use wi-th potassium silicate, many processes can advantageously use combinations of potassium silicate and sodium silicate. This allows the differing properties of the silicates to be utilized and combined in a single powder or application. Thus, mixtures of potassium and sodium silicates can be used to vary -the gelliny time or the duration of yelling in various applications. Since sodlum silicates are less expensive than potassium silicates, mix--tures also allow the cost of the silicate use to be reduced.
Another particularly suitable use for potassium silicate as opposed to sodium silicate solutions is as a preflush for cement-ing casing to a well bore. Particularly in situations where the well bore extends -through anhydrite earth formations, sodium silicate preflushes are no-t completely satisfactory since -they tend to flocula-te upon contact with a sufficient concen-tration of sodium in the earth formation. Accordingly, flushing the ear-th formation with an aqueous solution of potassium silicate allows penetration of -the formation by the potassium silicate which is more slowly jelled by calcium in the formation, by gelling agents circulated ahead of or with the cement, or other methods. This gelled penetration of the formation pro-tects the formation from deterioration during preflush and prepares the formation for bonding with the cement which follows.
In order to facilita-te a clear understancLing of the silicate compositions and me-thods of the present invention, the following examples are given.
Example 1 600 cc of acetone and 300 cc of a 40 Baumé, 3.32 ratio sodium silicate solution (Diamond Shamrock "grade 40" sodium silicate) are combined in a Waring blender at low speed. The speed of the blender is turned up to high to insure di.ssolution since the silicate solution instantaneously dehydrates. The resulting precipitate is filtered, washed wi-th additional acetone and allowed to dry overnight without heating. All of the fore-going is conducted at room temperature.
After drying overnight, the precipitate is brushed from the drying surface and redlssolved in water to its original solubility.
The solution is complete within 3 minute's. The above experiment is also performed wi-th -the same results utilizing ethanol and methanol as subs-titutes for the acetone and po-tassium silicate as a substitute for the sodium silicate. Drying more rapidly at 100F creates a material which is more easily dissolved.
The foregoing shows that rapidly dissolvable partially hydrated amorphous powdered silicates with high ratios can be 4 f prepared. ~lowever, this is a relatively expensive process.
Example 2 Powdered silicates are prepared by spray drying aqueous silicate solutions at room temperature. The molar ratios of the silicates vary from 1.8 to 3.2. Both sodium silicates and potas-sium silica-tes are prepared. The resulting powders are -tested for solubility, the results of which are shown in Table I below.
TABLE I - SOL~BILITY OF POWDERED SILICATES
Mole Ratio of Solubility Silicate/Alkali - - Na2O K2O
___ 1.8 S --2.0 SS --2.2 NS S
2.4 NS S
2.6 NS SS
2.8 NS NS
3.0 NS NS
3.2 NS NS
_ NS - Not soluble in tap water in 10 minutes time while stirring a 50~ solution.
SS - Slowly soluble in tap water - a hazy so-lution with some undissolved solids after 10 minutes stirring.
S - A relatively clear solution after no more than 10 minutes stirrillg at 80F.
5.
.
Z7~' This experiment shows that commercial spray dried prepara-tions of the powder of the present invention result in powder which has less solubility with molar ratios higher than 2.5.
example 3 In northeastern Utah, lost circulation of drilling mud is encountered while drilling at 12,000 feet. The drill striny is raised to a point known to be above the zone where lost circula-tion is likely. A potassium silicate solution is mixed from a rapidly soluble hydrated powder at ambient temperatures at which L0 it would be impossible to store and mix the liquid sodium silicate due to freezing. ~,000 lbs. of the potassium silicate powder are mixed with 35 barrels of water and injected through the drill string. After adding 5 barrels of fresh water spacer, 100 sacks of API Class G cement is mixed and injec-ted in a con-L5 ventional manner. Shut off is achieved and drilling is resumed.
As shown in this Example, potassium silicate powders can be utilized under conditions which make the use of sodium silicate solu-tions impossible. It shows that use of potassium silicates results in easier delivery methods with less concern for contami-nation.
Example 4 on an area where lost circulation is a cornmon problem in cementing surface pipe, a potassium silicate solution is pre-pared by dissolving 1000 lbs. of rapidly dissolving hydrated po-tassium silicate powder ln 380 c3allons of wa-ter. Addition of the powder is -through a conven-tional cement jet mixer. The solution is recirculated once through the mixer and then pumped as a preflush ahead of a conventional cement slurry. The ordinary calcium contamination inevitably present in the cement handling equipment which generally precludes the use of sodium silicate in a similar manner, causes no problems with the potassium silicate solution used.
The procedure is also used on three wells on successive days. Surface pipe depths are 680 feet, 579 feet and 626 feet.
In each case, the procedure is successful. Lost circulation is controlled and cement return is recovered at the surface.
This Example shows that potassium silicate pre~lushes ahead of cementiny produce desirable sealing and preparation oE the formation. It also shows that po-tassium silicates can be u-tilized where sodium silicates cannot due to contamination of the mixing equipment.
Example 5 In long string cementing of a casing (4800 to 5400 feet depths) through an anhydrite forma-tion, 12,000 lbs. of rapidly dissolving potassium sodium powder of the present invention are mixed with 12,000 lbs. of commercially available ethyl acetate and 300 barrels of water which solution is pumped as a preflush ahead of the conventional cement slurry. Following the gelling of the preflush in the formation and setting of the cement about the casing, sonic testing is performed and shows that the cement 7~
bond is satisfactory. Sodium silicate solutions might not be satisfactory since floculation often occurs upon encountering an anhydrite formation. It also shows the use of the ethyl acetate (a well-known acid forming gelation agent for silicates) to assist in and to assure proper gelling.
Example 6 In an offshore well, having a formation known to be unable to support the cement column, a powdered potassium silica-te solu-tion is mixed for sealing and stabilizing the formation. The solution is prepared by dissolving 120,000 lbs. of the highly dissolvable potassium silicate in 30,000 gallons of sea water.
This solution is pumped as a pre1ush -through the based drill string ahead of 200 barrels of cement slurry. The drill striny is then raised and the casing is lowered followed by conventional cementing of the casing. The resulting cemen-t bond with the casing achieves a satisfactory strength.
This Example shows that use of the powdered silicate in locations where storage of silica-te solutions would be impossible can be achieved. This Example also illustrates the reduced costs of transportation and handling of powdered silicates as compared to aqueous silicate solutions. Further, this Example shows that sea water and brines can be utilized with potassium silicates whereas sodium silicates tend to gel or floculate and be less effective.
Example 7 Highly dissolvable powdered po-tassium silicate is mixed with cement and tested in a s-tandard API thickening time test for an 8000 foot casing schedule. This test is made side-ky-side with a cement mixture utilizing an aqueous sodium silicate additive of equal silicate strength. The first test compares 3% by weight silicate-to-cement mixtures. The results show thickening times of about four hours for each. The viscosity of the potassium silicate run is substantially lower throughout the four-hour working time. Initial strengths are lower for the potassium silicate showing a delayed strength development in comparison with the sodium silicate.
Several similar -tests are run with varying concentrations of silicates using both fresh water and sea water. The results indicate similar thickening times for -the liquid sodium silicate and the powdered potassium silicate. The potassium silicate mixtures show lower viscosity slurries and delayed strength development.
This Example shows that highly dissolvable powdered sili-cates of -the present invention can be mixed with cement to pro-duce an improved slurry with controlable thickening times. It also shows that potassium silicate has properties which provide improved cement slurries for some uses.
What is claimed is:
3.2 NS NS
_ NS - Not soluble in tap water in 10 minutes time while stirring a 50~ solution.
SS - Slowly soluble in tap water - a hazy so-lution with some undissolved solids after 10 minutes stirring.
S - A relatively clear solution after no more than 10 minutes stirrillg at 80F.
5.
.
Z7~' This experiment shows that commercial spray dried prepara-tions of the powder of the present invention result in powder which has less solubility with molar ratios higher than 2.5.
example 3 In northeastern Utah, lost circulation of drilling mud is encountered while drilling at 12,000 feet. The drill striny is raised to a point known to be above the zone where lost circula-tion is likely. A potassium silicate solution is mixed from a rapidly soluble hydrated powder at ambient temperatures at which L0 it would be impossible to store and mix the liquid sodium silicate due to freezing. ~,000 lbs. of the potassium silicate powder are mixed with 35 barrels of water and injected through the drill string. After adding 5 barrels of fresh water spacer, 100 sacks of API Class G cement is mixed and injec-ted in a con-L5 ventional manner. Shut off is achieved and drilling is resumed.
As shown in this Example, potassium silicate powders can be utilized under conditions which make the use of sodium silicate solu-tions impossible. It shows that use of potassium silicates results in easier delivery methods with less concern for contami-nation.
Example 4 on an area where lost circulation is a cornmon problem in cementing surface pipe, a potassium silicate solution is pre-pared by dissolving 1000 lbs. of rapidly dissolving hydrated po-tassium silicate powder ln 380 c3allons of wa-ter. Addition of the powder is -through a conven-tional cement jet mixer. The solution is recirculated once through the mixer and then pumped as a preflush ahead of a conventional cement slurry. The ordinary calcium contamination inevitably present in the cement handling equipment which generally precludes the use of sodium silicate in a similar manner, causes no problems with the potassium silicate solution used.
The procedure is also used on three wells on successive days. Surface pipe depths are 680 feet, 579 feet and 626 feet.
In each case, the procedure is successful. Lost circulation is controlled and cement return is recovered at the surface.
This Example shows that potassium silicate pre~lushes ahead of cementiny produce desirable sealing and preparation oE the formation. It also shows that po-tassium silicates can be u-tilized where sodium silicates cannot due to contamination of the mixing equipment.
Example 5 In long string cementing of a casing (4800 to 5400 feet depths) through an anhydrite forma-tion, 12,000 lbs. of rapidly dissolving potassium sodium powder of the present invention are mixed with 12,000 lbs. of commercially available ethyl acetate and 300 barrels of water which solution is pumped as a preflush ahead of the conventional cement slurry. Following the gelling of the preflush in the formation and setting of the cement about the casing, sonic testing is performed and shows that the cement 7~
bond is satisfactory. Sodium silicate solutions might not be satisfactory since floculation often occurs upon encountering an anhydrite formation. It also shows the use of the ethyl acetate (a well-known acid forming gelation agent for silicates) to assist in and to assure proper gelling.
Example 6 In an offshore well, having a formation known to be unable to support the cement column, a powdered potassium silica-te solu-tion is mixed for sealing and stabilizing the formation. The solution is prepared by dissolving 120,000 lbs. of the highly dissolvable potassium silicate in 30,000 gallons of sea water.
This solution is pumped as a pre1ush -through the based drill string ahead of 200 barrels of cement slurry. The drill striny is then raised and the casing is lowered followed by conventional cementing of the casing. The resulting cemen-t bond with the casing achieves a satisfactory strength.
This Example shows that use of the powdered silicate in locations where storage of silica-te solutions would be impossible can be achieved. This Example also illustrates the reduced costs of transportation and handling of powdered silicates as compared to aqueous silicate solutions. Further, this Example shows that sea water and brines can be utilized with potassium silicates whereas sodium silicates tend to gel or floculate and be less effective.
Example 7 Highly dissolvable powdered po-tassium silicate is mixed with cement and tested in a s-tandard API thickening time test for an 8000 foot casing schedule. This test is made side-ky-side with a cement mixture utilizing an aqueous sodium silicate additive of equal silicate strength. The first test compares 3% by weight silicate-to-cement mixtures. The results show thickening times of about four hours for each. The viscosity of the potassium silicate run is substantially lower throughout the four-hour working time. Initial strengths are lower for the potassium silicate showing a delayed strength development in comparison with the sodium silicate.
Several similar -tests are run with varying concentrations of silicates using both fresh water and sea water. The results indicate similar thickening times for -the liquid sodium silicate and the powdered potassium silicate. The potassium silicate mixtures show lower viscosity slurries and delayed strength development.
This Example shows that highly dissolvable powdered sili-cates of -the present invention can be mixed with cement to pro-duce an improved slurry with controlable thickening times. It also shows that potassium silicate has properties which provide improved cement slurries for some uses.
What is claimed is:
Claims (33)
1. A rapidly dissolvable partially hydrated substan-tially amorphous powdered silicate having a molar ratio of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1 and a water content in the range of from about 12% to about 20% by weight of said hydrated silicate, said alkali metal being selected from the group consisting of sodium, potassium and mixture thereof.
2. The rapidly dissolvable powdered silicate of claim 1 wherein said ratio of silicon dioxide to alkali metal oxide is in the range of from about 2.0:1 to about 2.7:1.
3. The rapidly dissolvable powdered silicate of claim 2 wherein said ratio of silicon dioxide to alkali metal oxide is about 2.5:1.
4. The rapidly dissolvable powdered silicate of claim 1 wherein said alkali metal oxide is substantially all potassium oxide.
5. The rapidly dissolvable powdered silicate of claim 1 wherein the powdered silicate is partially hydrated and has a water content in the range of from about 14% to about 16% by weight of the hydrated silicate.
6. The rapidly dissolvable powdered silicate of claim 1 wherein a substantial portion of the particles which make up said powdered silicate have a size smaller than 40-mesh.
7. The rapidly dissolvable powdered silicate of claim 1 wherein the particles forming the powdered silicate are in an amorphous state of a type resulting from rapid drying and cooling of an alkali metal silicate solution.
8. A rapidly dissolvable partially hydrated powdered amorphous silicate having the formula (SiO2:M2O) - H2O
wherein:
M is selected from the group consisting of sodium, potassium and combinations thereof:
said powdered silicate has a water content in the range of from about 14% to about 16% by weight of the hydra-ted silicate; and said powdered silicate having a molar ratio of SiO2 to M2O in the range of from about 1.5:1 to about 3.3:1.
wherein:
M is selected from the group consisting of sodium, potassium and combinations thereof:
said powdered silicate has a water content in the range of from about 14% to about 16% by weight of the hydra-ted silicate; and said powdered silicate having a molar ratio of SiO2 to M2O in the range of from about 1.5:1 to about 3.3:1.
9. The rapidly dissolvable partially hydrated powdered silicate of claim 8 having a molar ratio of SiO2 to M2O in the range of from about 2.0:1 to about 2.7:1.
10. The rapidly dissolvable partially hydrated powdered silicate of claim 9 having a molar ratio of SiO2 to M2O of about 2.5:1.
11. The rapidly dissolvable partially hydrated powdered silicate of claim 8 wherein M is substantially all potassium.
12. The rapidly dissolvable partially hydrated powdered silicate of claim 8 wherein said powdered silicate is formed substantially of amorphous particles of a type produced by rapid drying and cooling of an alkali metal silicate solution.
13. The rapidly dissolvable partially hydrated powdered silicate of claim 12 wherein a substantial portion of the particles which make up said powdered silicate have a size smaller than 40-mesh.
14. The powdered potassium silicate of claim 11 having a molar ratio of silicon dioxide to potassium oxide in the range of from about 2.0:1 to about 2.7:1.
15. The powdered potassium silicate of claim 11 having a molar ratio of silicon dioxide to potassium oxide of about 2.5:1.
16. The powdered potassiumsilicate of claim 11 wherein said powder is comprised of amorphous particles of the type produced by rapid drying and cooling of a potassium silicate solution.
17. The powdered potassium silicate of claim 11 wherein said powder is comprised of amorphous particles of the type produced by precipitation of potassium silicate from a potassium silicate solution resulting from the introduction of hydrophilic material into the solution.
18. A rapidly dissolvable partially hydrated powdered amorphous silicate comprising a mixture of sodium silicate and potassium silicate wherein:
the molar ratio of silicon dioxide to sodium oxide in the sodium silicate is in the range of from about 1.5:1 to about 3.3:1, the molar ratio of silicon dioxide to potassium oxide in the potassium silicate is in the range of from about 1.5:1 to about 3.3:1, and said powdered silicate has a water content in the range of from about 14% to about 16% by weight of hydrated silicate.
the molar ratio of silicon dioxide to sodium oxide in the sodium silicate is in the range of from about 1.5:1 to about 3.3:1, the molar ratio of silicon dioxide to potassium oxide in the potassium silicate is in the range of from about 1.5:1 to about 3.3:1, and said powdered silicate has a water content in the range of from about 14% to about 16% by weight of hydrated silicate.
19. The hydrated powdered silicate of claim 18 wherein the powder is comprised essentially of amorphous particles of the type produced by rapid drying and cooling of a potas-sium silicate and sodium silicate solution.
20. The hydrated powdered silicate of claim 19 wherein a substantial portion of the particles which make up said powdered silicate have a size smaller than 40-mesh.
21. The hydrated powdered silicate of claim 18 wherein said powder consists essentially of amorphous particles of the type produced by precipitation of a potassium silicate and sodium silicate solution resulting from the addition of hydrophilic material to the solution.
22. The hydrated powdered silicate of claim 21 wherein a substantial portion of the particles which make up said powdered silicate have a size smaller than 40-mesh.
23. A method of preparing an earth formation for bonding with cement comprising the step of flushing the earth forma-tion with an aqueous solution of potassium silicate having a molar ratio of silicon dioxide to potassium oxide in the range of from about 1.5:1 to about 3.3:1, said aqueous solution of potassium silicate being prepared by dissolving in water a highly dissolvable,partially hydrated,powdered potassium silicate having a water content in the range of from about 14% to about 16% by weight of said partially hydrated powdered silicate and wherein said powder is comprised of amorphous particles of said potassium sili-cate.
24. A method of preparing an anhydrite earth formation for bonding with cement comprising the step of flushing said anhydrite earth formation with an aqueous solution of potas-sium silicate having a molar ratio of silicon dioxide to potassium oxide in the range of from about 1.5:1 to about 3.3:1, said aqueous solution of potassium silicate being prepared by dissolving in water a highly dissolvable, partially hydrated, powdered amorphous potassium silicate having a water content in the range of from about 14%
to about 16% by weight of said partially hydrated silicate.
to about 16% by weight of said partially hydrated silicate.
25. A method of preparing an aqueous silicate solution for use in connection with sealing or cementing earth forma-tions, comprising the steps of:
preparing a rapidly dissolvable partially hydrated powdered amorphous silicate having a molar ratio of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1, wherein said alkali metal is selected from the group consisting of sodium, potassium and mixtures thereof, and having a water content in the range of from about 14% to about 16% by weight of said partially hydrated silicate;
transporting said powdered silicate to an earth formation location; and dissolving said powdered silicate.
preparing a rapidly dissolvable partially hydrated powdered amorphous silicate having a molar ratio of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1, wherein said alkali metal is selected from the group consisting of sodium, potassium and mixtures thereof, and having a water content in the range of from about 14% to about 16% by weight of said partially hydrated silicate;
transporting said powdered silicate to an earth formation location; and dissolving said powdered silicate.
26. The method of claim 25 wherein said silicate con-sists essentially of potassium silicate and wherein said dissolving step comprises mixing said powdered silicate with brine.
27. A method of sealing an earth formation containing di- or polyvalent cations or salts, comprising the steps of:
preparing a potassium silicate solution of a type which will gel when combined with di- or polyvalent cations or salts of the type in the earth formation and will pene-trate the formation without premature flocculation and gelation by mixing water with a highly dissolvable partially hydrated powdered amorphous potassium silicate having a molar ratio of silicon dioxide to potassium silicate in the range of from about 1.5:1 to about 3.3:1 and a water content in the range of from about 14% to about 16% by weight of said partially hydrated potassium silicate;
introducing the prepared potassium silicate solu-tion into the earth formation; and allowing the potassium silicate solution to gel into a relatively firm impermeable mass thereby sealing the formation.
preparing a potassium silicate solution of a type which will gel when combined with di- or polyvalent cations or salts of the type in the earth formation and will pene-trate the formation without premature flocculation and gelation by mixing water with a highly dissolvable partially hydrated powdered amorphous potassium silicate having a molar ratio of silicon dioxide to potassium silicate in the range of from about 1.5:1 to about 3.3:1 and a water content in the range of from about 14% to about 16% by weight of said partially hydrated potassium silicate;
introducing the prepared potassium silicate solu-tion into the earth formation; and allowing the potassium silicate solution to gel into a relatively firm impermeable mass thereby sealing the formation.
28. A method of sealing a vugular matrix or channel earth formation comprising the steps of:
alternately introducing into the formation a potassium silicate solution and a fluid containing di- or polyvalent cations of a type suitable for gelling the potassium silicate solution;
said potassium silicate solution being prepared by mixing water with a highly dissolvable partially hydrated powdered amorphous potassium silicate having a molar ratio of silicon dioxide to potassium silicate in the range of from about 1.5:1 to about 3.3:1 and a water content in the range of from about 14% to about 16% by weight of said par-tially hydrated potassium silicate; and allowing the potassium silicate solution to gel thereby sealing the vugular, matrix or channel portions of the earth formation.
alternately introducing into the formation a potassium silicate solution and a fluid containing di- or polyvalent cations of a type suitable for gelling the potassium silicate solution;
said potassium silicate solution being prepared by mixing water with a highly dissolvable partially hydrated powdered amorphous potassium silicate having a molar ratio of silicon dioxide to potassium silicate in the range of from about 1.5:1 to about 3.3:1 and a water content in the range of from about 14% to about 16% by weight of said par-tially hydrated potassium silicate; and allowing the potassium silicate solution to gel thereby sealing the vugular, matrix or channel portions of the earth formation.
29. The method of claim 28 wherein said fluid con-taining di- or polyvalent cations is Portland cement con-taining calcium cations.
The method of claim 28 wherein said fluid con-taining di- or polyvalent cations comprises brine.
31. A cementitious mixture comprising a mixture of cement powder and a rapidly dissolvable, partially hydrated, powdered amorphous silicate having a molar ratio of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1 and wherein said alkali metal is selected from the group consisting of sodium, potassium and mixtures thereof, and having a water content in the range of from about 14% to about 16% by weight of said partially hydrated powdered silicate.
32. An improved method of sealing or cementing an earth formation of the type utilizing a silicate solution, the improvement comprising the steps of:
preparing said silicate solution at the earth formation location by dissolving a rapidly dissolvable partially hydrated, powdered amorphous silicate having a molar ratio of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1 and wherein said alkali metal is selected from the group consisting of sodium, potassium and mixtures thereof; and utilizing the resulting solution in said sealing cementing method.
preparing said silicate solution at the earth formation location by dissolving a rapidly dissolvable partially hydrated, powdered amorphous silicate having a molar ratio of silicon dioxide to alkali metal oxide in the range of from about 1.5:1 to about 3.3:1 and wherein said alkali metal is selected from the group consisting of sodium, potassium and mixtures thereof; and utilizing the resulting solution in said sealing cementing method.
33. The method of claim 32 which further comprises the step of adding a gelling agent to said solution.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US265,821 | 1981-05-21 | ||
US06/265,821 US4391643A (en) | 1981-05-21 | 1981-05-21 | Rapidly dissolvable silicates and methods of using the same |
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Publication Number | Publication Date |
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CA1201274A true CA1201274A (en) | 1986-03-04 |
Family
ID=23012008
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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CA000403443A Expired CA1201274A (en) | 1981-05-21 | 1982-05-20 | Rapidly dissolvable silicates and methods of using the same |
Country Status (6)
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US (1) | US4391643A (en) |
AU (1) | AU552705B2 (en) |
BR (1) | BR8202896A (en) |
CA (1) | CA1201274A (en) |
GB (1) | GB2099412B (en) |
MY (1) | MY8700123A (en) |
Families Citing this family (31)
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US4545820A (en) * | 1982-07-30 | 1985-10-08 | Gas Research Institute | Soil stabilizer and method for stabilizing soil |
US4493592A (en) * | 1982-09-28 | 1985-01-15 | Halliburton Company | Grouting method |
DE3373465D1 (en) * | 1982-12-16 | 1987-10-15 | Dynamit Nobel Ag | Water-containing hardenable shaped masses based on inorganic components, and method of producing shaped bodies |
US4625802A (en) * | 1984-07-03 | 1986-12-02 | Marathon Oil Company | Potassium silicate clay stabilization process |
US4964465A (en) * | 1989-11-06 | 1990-10-23 | Texaco Inc. | Method employing liquidized sand for controlling lost circulation of drilling fluids |
SE468091B (en) * | 1990-11-14 | 1992-11-02 | Eka Nobel Ab | ALKALIMETAL SILICATE IN SOLID FORM CONTAINING SODIUM AND POTENTIAL Potassium, PREPARED FOR ITS PREPARATION AND ITS USE IN CLEANING COMPOSITIONS |
SE468092B (en) * | 1990-11-14 | 1992-11-02 | Eka Nobel Ab | ALKALIMETAL SILICATE IN SOLID FORM CONTAINING SODIUM AND POTASSIUM, PREPARED FOR ITS PREPARATION AND ITS USE IN CLEANING COMPOSITIONS |
AU664742B2 (en) * | 1992-05-11 | 1995-11-30 | 3M Australia Pty Limited | Bar code use security arrangement |
FI96848C (en) * | 1993-02-22 | 1996-09-10 | Pentti Valoranta | Powdered product containing finely divided alkali silicate and process for its preparation |
ES2111327T3 (en) * | 1993-08-23 | 1998-03-01 | Pq Corp | AMORPHIC ALKALINE METAL SILICATE, PROCEDURE AND USES. |
GB9501099D0 (en) * | 1995-01-20 | 1995-03-08 | Brunner Mond & Co Ltd | Silicate solutions |
EP0770661A1 (en) * | 1995-10-27 | 1997-05-02 | B W Mud Limited | Lubricant for drilling mud |
US5961663A (en) * | 1997-05-29 | 1999-10-05 | Colgate-Palmolive Co. | Microwave-dried amorphous alkali metal silicate powders and their use as builders in detergent compositions |
IL128082A0 (en) * | 1998-01-21 | 1999-11-30 | Alliant Defense Electronic Sys | Moisture-degradable alkali oxide siliceous material and electronagnetic radiation-interactive article comprising same |
US6508306B1 (en) * | 2001-11-15 | 2003-01-21 | Halliburton Energy Services, Inc. | Compositions for solving lost circulation problems |
US7786049B2 (en) * | 2003-04-10 | 2010-08-31 | Halliburton Energy Services, Inc. | Drilling fluids with improved shale inhibition and methods of drilling in subterranean formations |
US7087554B2 (en) * | 2003-04-10 | 2006-08-08 | Halliburton Energy Services, Inc. | Drilling fluids with improved shale inhibition and methods of drilling in subterranean formations |
US6902002B1 (en) * | 2004-03-17 | 2005-06-07 | Halliburton Energy Services, Inc. | Cement compositions comprising improved lost circulation materials and methods of use in subterranean formations |
US7607483B2 (en) * | 2004-04-19 | 2009-10-27 | Halliburton Energy Services, Inc. | Sealant compositions comprising colloidally stabilized latex and methods of using the same |
US7488705B2 (en) * | 2004-12-08 | 2009-02-10 | Halliburton Energy Services, Inc. | Oilwell sealant compositions comprising alkali swellable latex |
US20070111901A1 (en) * | 2005-11-11 | 2007-05-17 | Reddy B R | Method of servicing a wellbore with a sealant composition comprising solid latex |
US20070111900A1 (en) * | 2005-11-11 | 2007-05-17 | Reddy B R | Sealant compositions comprising solid latex |
US20060217270A1 (en) * | 2005-03-24 | 2006-09-28 | Halliburton Energy Services, Inc. | Wellbore servicing fluids comprising resilient material |
US7264053B2 (en) * | 2005-03-24 | 2007-09-04 | Halliburton Energy Services, Inc. | Methods of using wellbore servicing fluids comprising resilient material |
US7943555B2 (en) | 2005-04-19 | 2011-05-17 | Halliburton Energy Services Inc. | Wellbore treatment kits for forming a polymeric precipitate to reduce the loss of fluid to a subterranean formation |
US7905287B2 (en) * | 2005-04-19 | 2011-03-15 | Halliburton Energy Services Inc. | Methods of using a polymeric precipitate to reduce the loss of fluid to a subterranean formation |
US7833945B2 (en) | 2005-07-15 | 2010-11-16 | Halliburton Energy Services Inc. | Treatment fluids with improved shale inhibition and methods of use in subterranean operations |
US8455404B2 (en) | 2005-07-15 | 2013-06-04 | Halliburton Energy Services, Inc. | Treatment fluids with improved shale inhibition and methods of use in subterranean operations |
US7341106B2 (en) * | 2005-07-21 | 2008-03-11 | Halliburton Energy Services, Inc. | Methods for wellbore strengthening and controlling fluid circulation loss |
EP2354091B1 (en) * | 2010-02-06 | 2017-11-29 | Cognis IP Management GmbH | Silicate solutions stable in storage |
CN112429744A (en) * | 2020-11-02 | 2021-03-02 | 山东联科科技股份有限公司 | Production method of anhydrous sodium metasilicate |
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US3566967A (en) * | 1969-06-19 | 1971-03-02 | Pan American Petroleum Corp | Thermal plugging with silicate solutions |
US3679001A (en) * | 1970-03-02 | 1972-07-25 | Gilman A Hill | Well drilling method |
US4014174A (en) * | 1975-10-28 | 1977-03-29 | N L Industries, Inc. | Method of simultaneously strengthening the surface of a borehole and bonding cement thereto and method of forming cementitious pilings |
US4081029A (en) * | 1976-05-24 | 1978-03-28 | Union Oil Company Of California | Enhanced oil recovery using alkaline sodium silicate solutions |
US4120369A (en) * | 1977-10-03 | 1978-10-17 | Union Oil Company Of California | Method for drilling a well through unconsolidated dolomite formations |
US4257483A (en) * | 1979-01-11 | 1981-03-24 | The Dow Chemical Company | Method of well completion with casing gel |
-
1981
- 1981-05-21 US US06/265,821 patent/US4391643A/en not_active Expired - Lifetime
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1982
- 1982-05-17 GB GB8214250A patent/GB2099412B/en not_active Expired
- 1982-05-19 BR BR8202896A patent/BR8202896A/en unknown
- 1982-05-20 AU AU83898/82A patent/AU552705B2/en not_active Ceased
- 1982-05-20 CA CA000403443A patent/CA1201274A/en not_active Expired
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1987
- 1987-12-30 MY MY123/87A patent/MY8700123A/en unknown
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GB2099412B (en) | 1986-01-15 |
GB2099412A (en) | 1982-12-08 |
BR8202896A (en) | 1983-05-03 |
AU8389882A (en) | 1982-11-25 |
US4391643A (en) | 1983-07-05 |
AU552705B2 (en) | 1986-06-19 |
MY8700123A (en) | 1987-12-31 |
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