US2944792A - Turbines for drilling and coring - Google Patents

Description

July 12, 1960 c. GROS 2,944,792

TURBINEIS FOR DRILLING AND CORING Filed May 16, 1957 INVENTOR CHARLES GROS ATTORNEYS 2,944,'192 TURBINES FOR DRILLING CURING Charles Gros, La Tronche, France assignor to Etablissements Neyrpic, Grenoble, France, a corporation of France a i 7 Filed May 16, 1951, Ser. No. 059,635 7 U Claims priority, application France May 28, 1 956 6 Claims. (Cl. 255-4) ice,

on the shaft along an exterior portion opposite the co-. acting rotor elements of the turbine which are secured to' the sleeve-like body member which is rotatably mounted upon the shaft. Because of this construction, the two stationary parts of the'turbine', namely, the stator and the coring tube, are both arranged concentrically within the movable part, the rotor.' Thus, the part of the turbine that is rotating at a high speed, is only directly associated with one stationary part. This arrangement therefore is less complicated and less costly to maintain and service than prior known constructions in which the rotating part is located between and directly associated with two stationary parts of the turbine.

Other objects and advantages of the invention, as well as the novel details of construction thereof will become apparent from the following description when read in supported in depending relation thereby. While the body member is securely connected. to the drill string, it canf not be considered as a truly stationary member because it is actually subject tea-certain variable torsion due to a the force applied to the drilling bit and to the elasticity of the drill string. Further, it may befound desirable under certain drilling conditions to impart arotation,.i.n.-.

one directionor the other, to the drill stringitself. There-- fore, it is believed more accurate to statetha't the stator of the usual turbo-corer is quasi-fixed or fixed with-relationtothedrillstring. 1 f Located concentrically withsuch body member is a hollow shaft which bears the rotor elements of the turbine and the drilling bit. Usually the shaft is rotatably supported by the body member through a system of bearings connection with the accompanying drawing which shows byway of example, in longitudinal section, a turbo-corer embodying the features of the invention.

As shown in the drawing, the shaft 1 of the turbine is tubular in shape and has associated therewith an outer casing or sleeve member 2 which rotates freely about the shaft L 'A'set of stator blades ,3 is mounted on the shaft 7 1 near they lower end thereof, being held in assembled relation thereon by the locking nut 4-. -Aj coring tube 5 is'supported by and positioned withinthe shaft 1, such support ,being'provided by the inwardly inclined annular shoulder 6 and the cooperating plug member -7 which is 7 provided with a complementary seating'surface, this-plug being-secured in-tube .5,asby welding or by being threaded therein. Therotorblades 8 are assembled withj, in "casing 2in stacked;- and interleaved. relation With=the stator blades and are supported by this casingfbeingheld; in'plac'e by the ring nut 9 which in turn carries threads on the exterior surface onitslower end to which the. sleeve-extension 39 of the drilling tool 10- isattached.

The'shaft l'is provided with an externally threaded POI'rT which are independent of the rotorand stator elements and are axially spaced relative to these elements- Mounted within the turbine shaft is a removable coring tube designed to receive and to retain the drilled core and to hold the latter when the coring tube is removed from the turbine. Because of the danger of possible breakage of the core, the coring tube is not permitted to rotate with the shaft,-but is connected to the body member. Accordingtobne .known method of accomplishing this, the coring tube is provided at its upper end with a plug which has a tapered body-and which seats in a conical seat provided ina fixed member connected. to the body member. The plug is maintained securely in place on the seat during the operation of the turbine by the pressure of the circulating and: power. transmitting fluid which drives the drilling'toohthroug'h the turbine, and which usually; consists of a drilling'mud flowing under pressure. -.As. a resultof this .arrangement,..th e coring tube, like the body member of the .turbine, is fixed with-relation to the drill string during the operation of the turbine. 1 7

The present invention has for its primary object to provide a more'simply constructed turbo-corer in which the coring tube is mounted on a hollow turbine shaft that is stationary with relation to. the outer sleeve-like body member or casing which is rotated about such shaft by the action of the power transmitting fluid on the rotor and stator blades of the turbine. This is accomplished by directly connecting the shaft to the drill string so that it is fixed with relation to, such string. The coring. tube in this constructionis mounted Within and directly sup ported by the'shaft'. The stator elements are mounted tion 35 at the upper end thereof for attaching the shaft 1 in fixed relation to the drill string and for supporting the turbine assembly on the drill string. The further details ofthe embodiment shown will be described in connection with the'following description of the operation of the device. I n Thedrilling mud flowing down through the drill string under pressure continues throughthe upper end of the hollow shaft 1 and through the bore 37 of the upper por-.

tion to the outlet ports lz leading to the space 17 between the hollow shaft and the casing 2 which leads to the turbine proper. The drilling mud flowing down through the hollow shaft 1 exerts pressure on the-plug 7 to main;

' tain the latter fixed in position within the shaft. -As is shown in the drawing, the plug 7 has an annular taperingseating" surface adapted to seat in ,a correspondingly shaped seat 6 provided in the shaft below the ports 12. Whensoseated under thev pressure of the drilling mud, the-plug {7 prevents any passage of the circulating fluid.

into the portion of the shaft bore belowthe tapered seat turbine within the lower portion of the shaft. The coring tube has an external diameter less than the internal diameter of the lower portion of the shaft so as to provide.

an axially extending, annularly-shaped space 13 between such tube and theshaft from the plug seat down to the lower'end of such shaft. The coring tube 5 is provided with one or more openings 14in its side wall adjacent "its upper end for the purpose of relievingthe pressure on i Patented July 12,1960- drilling mud entrapped in the tube as the core advances upwardly in the tube and to permit the mud to escape into the annular space 13 from which it discharges into an area where the mud is under a pressure'corresponding to the pressure at the outlet of the turhi eisection The coring tube 5 extends downwardly beyond the lower end of the shaft 1 to a point adjacent the rotary cutters of the drilling tool it The tube 5 at this lower end bears in a bushing 41 which is secured in the drilling tool and is rotatable with this tool. The bottom end of the coring tube 5 is provided with spring pressed ratchets which are biased inwardly toward the core and aid in severing the core from the earth formation upon upward movement of the coring tube when the core is to be severed and withdrawn. The upper end 16 of the coring tube supporting plug 7 is formed to enable it to be engaged by a suitable tool and withdrawn upwardly through the shaft 1 together with the coring tube and the core that has been formed in the tube during the coring operation. It will be understood that the plug 7 and coring tube 5 may be withdrawn upwardly through both the upper portion of the shaft and the drill string without detaching the turbo-corer unit, and likewise, if desired, the coring tube may be returned to its position within the shaft for obtaining a further core section without raising the drill string. During the lifting of coring tube 5 the core is retained inside the same by the ratchets 15.

The drilling mud flowing down through the shaft 1 is discharged through the spaced ports 12 into an annular chamber or passage 17 formed between shaft 1 and theouter sleeve-like casing 2 of the turbo-corer. As previously indicated, the shaft constitutes the stator of the turbine and has mounted upon the blade-carrying section 18 thereof the fixed stator elements which include blades 3. These stator elements are secured by suitable means such as keys and keyways (not-shown) on the shaft between a shoulder 19 formed at the juncture of shaft section '18 with the main body of the shaft 1 and the nut 4 which is in threaded engagement with the lower .end of shaft section 18. The rotor elements which include blades -8 of the turbo-corer illustrated are similarly mounted on that portion of the rotatable casing 2 that is coextensive with section 18 of the shaft 1 and which is designated by the numeral 20. The rotor elements and blades 8 are secured in position between a shoulder 21 formed in sleeve or casing 2 at the upper end of section and a ring nut 9' threadedly connected to the lower end of easing section 20. The stator and rotor elements and blades 3 and 8, respectively, are constructed similarly to the stator and rotor elements and blades in the turbine construction disclosed in my copending application Serial No. 660,405, filed May 20, 1957, corresponding to French appln. No. P.V. 3826, filed May 28, 1956, so that in addition to, performing the normal turbine functions for which they were designed, they form part of and funct-ion in the nature of a multiple collar thrust bearing unit to support and center the rotor casing 2 and to take care of the thrust thereof. 7

,As in the turbine structure described in more detailin my said copending application, the rotor elements which comprise blades 8 of the instant turbine constitute the movable parts of the thrust bearing unit and the stator elements which comprise blades 3 constitute the fixed parts of such unit. Similarly, there are located between the rotor and stator elements of the turbine, stationary annular U-shaped bearing shoes formed of any suitablebearing material such as for example, a suitable bearing metal or a synthetic rubber such as neoprene. The annular U-shape of these bearing shoes is such that each provides anoutwardly opening annular groove into whichan annularly-shaped portion 22 of a rotor element carried at the end of the blade 8 may be contained. The upper side wall 23 of each U-shaped shoe is located between the annular-shaped portion 22 of each rotor element 8 and the annula ly-shaped -:1 Qrticn 2140f t e stator 91;-

ment carrying blade 3 positioned adjacently above each such rotor element and its blade .8- QWQI W ilv of each U-shaped shoe is located between such rotor portion 22 and the annularly-shaped portion 24 of the stator element and its blade 3 positioned adjacent-1y below such rotor element and its blade 8. The inner wall 26 of each U-shaped shoe is sandwiched between the portion 22 of its r espondin rot r element '8 an t e sha section 18. The rotor 2 may also be guided and supported at its ppe end on shaft se tion 1 b a radia he r n .2 is. carried by the shaft 1 s as to be disposed in rotative bearing relation to the inner surface of rotatable sleeve or casing m mber r The drilling mud discharging from the downstream end of the, turbine after Passing succe sively through the blades 3 and 8 flows downwardly through a passageway 28 formed between the nut 4 and the ring nut 9 and thence through an annular passage 29 between the coring tube 5 and the inner wall surface of the ring nut 9. annular passageway 29 opens into an enlarged annular passageway 30 defined by" the coring tube and the inner wall surface ofthe the sleeve extension 39 of the drilling tool. The drilling mud after traversing these passageways discharges from the lower end of the passage 30 through a plurality of annularly arranged passages 31 into the vicinity of the rotary cutters 32. r

- The coring tube 5 at its upper end is provided with a ring of spaced discharge ports 14 which put the top 7 end of the chamber defined by the coring tube into communication with the upper end of the annular space 13 between such coring t-u'be and the shaft. Since the lower end of chamber 13 is in communication with the discharge passageway at the downstream end of the turbine, the pressure in chamber 13 approximates the hydrostatic pressure of the column of drilling mud at the point in the bore hole outside the turbine and at the leyelof the discharge from the turbine. This pressure is, of course, very substantially below that prevailing within shaft 1 above the turbine. Because of the provision for com; munication between the interior of the coring tube and a point of relatively low pressure in the flow of the drilling mud, any tendency for the pressure to build up in V the drilling mud initially present in the coring tube 5 due to rise of the core of the earth formation into the tube as the drill penetrates the formation is avoided and resistance to such penetration that otherwise might occuris avoided. The expelled drilling mud flows down through the annular chamber 13 to join with the drilling mud beingdischarged from the downstream end of the turbine.

While I have hereinabove described and illustrated in the drawing a preferred embodiment of my invention, it will be understood that various changes and modif cations of the construction thereof maylbemade without departing from the invention which is not to "-be deemed asflimited otherwise than as indicated by the scope of the append c a msi I claim:

. A or n turbi e unit compr sin a t ular h h dapted to b conne e a a give en t ereo to dril strin in fi e re a i n to s d drill t n r a sleeve di po e sp t a l th the ais rh 'aa PIO- vi as a wa of the sl ev e tend bo s i ha along a length of said shaft and in spaced relation thereto t d fi e betwee sa d s a adsaid s e 'a nu passag fo 19W dr n f u thro Said pa ener l alon s id a is in the d r cti n from d iven and o th sha towa d the oth r end e e m an u por n sa sleev 9 sa d sha t o rotation of sa sl e on said shaft an sta o el me c d y a d shaft, r to ments. c rri d y a d sleeve f a i n the ith, sa s a or and t o dem ri es otive y pro i in ator a d m q b ade dis os d n d pa a e n reane ti e rela io to each. ot e a d 9 a to be engaged 'by said dr flu for e i st ng movement of said rotor blades and elements with respect to said stator blades and elements to produce rotation of said sleeve about said shaft on said shaft axis, said sleeve at the end thereof along said axis from said given end of said shaft being adapted to carry a core forming bit, and a core tube disposed within said tubular shaft coaxially therewith and supported by said shaft adjacent the end of said core tube disposed toward said given end of said shaft, said core tube extending to the opposite end thereof disposed adjacent said bit for receiving into said opposite end the core formed by said bit.

2. A coring turbine unit as defined in claim 1 in which said core tube is disposed with the exterior surface thereof in spaced relation to the interior surface of said tubular shaft to provide an annular chamber about said core tube extending therealong, means within said tubular shaft engaging said'end of said tube disposed toward said given end of said shaft and engaging said shaft internally. for closing against fluid flow from said tubular shaft to said annular chamber, said core'tube being pro vided with an opening communicating between the interior of said core tube and said annular chamber, said to said first portion and providing a bore of reduced cross section with respect to said given cross section of said first portion of said shaft, said shaft providing an annular seat adjacent the juncture of the bores of said two portions, said core tube being disposed in thebore of said second portion, and a member disposed in the bore of said first portion and secured to said core tube'adjacent the end of said core tube disposed toward said first portion, said member removably engaging said annular seat for supporting said member and said core tube on said seat and for closing against flow of driving fluid between said bores of said two portions of said shaft, said core tube having a cross section in relation to the bore of said second portion to provide for axial movement of said core tube together with said member for withdrawing said core tube from said shaft in the direction toward said given end of said shaft.

4. A coring turbine unit as defined in claim 3 in which the exterior surface of said core tube is disposed in spaced relation of the bore of said second portion of said shaft to provide an annular chamber about said core tube ly adjacent said shaft provide annular bearing surfaces perpendicular to the axis of said shaft and in spaced relation to each other along said axis, said rotor elements providing at portions thereof disposed inwardly toward said shaft annular bearing surfaces perpendicular to said shaft axis in spaced relation to each other along said axis and respectively in thrust transmitting relation to said annular bearing surfaces of said stator elements to oppose thrustalong said axis developed by said driving Q fluid engaging saidstator and rotor blades.

6. A. coring turbine unit as defined in claim 1 in which said stator elements at portions thereof disposed inwardly adjacent said shaft provide annular bearing surfaces perpendicular to the axis of said shaft and in spaced relation to each other along said axis, said rotor elements providingat portions thereof disposed inwardly toward said shaft annular bearing surfaces perpendicular to said shaft. axis in spaced relation to each other along said axis and in opposed spaced relation to respective annular bearing surfaces of said stator elements, and bearing means disposed between adjacent opposed annular bear ing surfaces respectively of said stator and rotor elements and coacting therewith to oppose thrust along said axis developed by said driving fluid engaging said stator and rotor elements. I

References Cited in the file of this patent UNITED STATES PATENTS 1,348,815 Lewis Aug. 3, 1920 2,660,402 Devine et al. Nov. 24, 1953 FOREIGN PATENTS 709,608 Great Britain May 26, 1954 OTHER REFERENCES Russians Boast Success for Their Turbodrills, F. A.

Trebin, Oil & Gas Journal, November 1955, vol. 54, No. 27, pp. 97-99, see especially page 99.

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