US1970295A - Apparatus for treating well fluids - Google Patents

Description

Aug. 14, 1934.

H` H. FlTrzPATRlcK APPARATUS FOR TREATING WELL FLUIDS Filed Nov. 19,' 1927 5 Sheets-Sheet l Aug. 14, 1934. Vl-LH. FiTzPATRlcK 1,970,295

APPARATUS FOR TREATING WELL FLUIDS Filed Nov. 19, 1927 5 Sheets-Sheet 2 Aug. 14, 1934. H. H. FITZPATRICK APPARATUS FOR TREATING WELL FLUIDS 5 Sheens-Sheet 5 Filed NOV. 19, 1927 Aug. 14, 1934. H. H. FnzPA'TRlcK 1,970,295

APARATUS FOR TREATING WELL FLUIDS Filed Nov. 19, 1927 S-Sheets-Sheet 4 Zzaenzfof Aug. 14, 1934. H. H. FITZPATRICK 1,970,295

APPARATUS AFOR TREATING" WELL FLUIDS Filed Nov. 19, 1927 5 Sheets-Sheet 5 0 3 M 5 6 F w 1T 6. 5 1T. 5 5 5 IT. A f ,wf

@@NNHNHH recovery, by pumping Famed aug. i4, naarx 1,970,295 APPARATUS FOR TBEATHNG WELL FLUEDS Howard lvl. Fitzpatrick, Amarillo, Tex., assigner to Faraiin Heater Engineering Corporation, Wilmington, Dele, a corporation of Delaware Application November 19, 1927, Serial No. 334,493

7 Claims.

n This invention relates in general to treatment of well iiuids, particularly in the treatment of such fluids during the process of recovery of sa e from the well, such, for instance, as in the or otherwise, o oil and the like from an oil well. This application is a continuation in part of my copending application, Ser. No. 109,282, allowed February 24, 1928.

It is well known to those familiar with the art of recovery oi petroleum that it is not unusual to reach the gas bearing formation at a depth of from 2300 to 2850 feet, and from below this depth the oil itself is usually obtained.

Due to the pressure and temperature of the gas acting upon the well casing in some formations a refrigeration of the oil being pumped or otherwise flowing from the Well sometimes results, the parairin constituentsv ci the oil congealing rendering the oil so viscous that operation of the pump or flow of the oil freely from the well is materially impaired or entirely stopped.

The eiorts in overcoming this difficulty known to me prior to this invention have met with scant success, it not being uncommon to employ steam heat applied to the so-called refrigerating' zone, that is, the introduction of heat by steam under pressure or even hot water or the like. The employment of steam for this purpose has not met with the desired. success owing to the impracticability of applying the heat at the desired point without condensation of the steam resulting.

The present invention has for its principal object, thereore, the provision of an improved method of and apparatus for treating oil well products, particularly to prevent coagulation or congealing of the cil due either to the result mentioned above or any other factor in the recovery of the oil tending to reduce the oil to a state of viscosity preventing its ready recovery.

Further objects and advantages of the present invention reside in the provision or an improved method of and apparatus for maintaining the oil or the like during recovery from the well at a predetermined suitable temperature during such recovery; the provision of an improved method of and apparatus for applying heat to the oil so that the heat is concentrated at a desired point; the provision of an improved electrical apparatus for attaining the results desired; the provision of an improved heating apparatus for oil wells and the like which may be applied to the standard pumping mechanism without material alteration of any existing structures; the provision of an improved method of and appara- (Cl. 10B-1) tus for applying heat to the oil in an cil well, or the like, and for regulating both the degree of heat applied and the locality of its application.

ln general, in accordance with my invention,

I provide an electrical heating means which I f find is more practicable of application to the desired degree and locality than other means known to me and by which such apparatus may be conveniently introduced into the well either, as in one form of the invention, as a part of the pumping mechanism, or as an apparatus distinct and separate from, but associated with, the pumping mechanism whereby to attain the application or heat subject to variation, as' desired, at various depths, either simultaneously or independently.

The foregoing objects and advantages, together with those which may appear or be pointed out as this description proceeds, are attained by the methods hereinafter described and structural embodiments illustrated in the accompanying drawings, in which:

Figure i. is illustrative of an oil well incorporating my improved heating means therein.

Figure 2 is an alternative form of this invention.

Figure 3 is a central vertical longitudinal section through an oil well, the operating cable and heating device being shown in elevation and illustrating details of Figure 2.

Figure 4 is a side elevation of one of the heating devices.

Figure 40, is a cuits.

Figure 5 is an elevational View, taken at a right angle to the position shown in Figure ll.

Figure 6 is a plan View of the device.

Figure l is a side elevation of the cable carrying the conductors.

Figure 8 is an elevation of the inner side of one of the housing or casing sections.

Figure 9 is a longitudinal section taken on line 9-9 of Figure 5.

Figure 10 is a horizontal section taken on line 10-10 of Figure 9.

Figure 11 is a side elevation of one of the resistance elements.

Figure l2 is a horizontal section taken on line 12-12 oi Figure 9.

Figure i3 is a perspective end gaskets.

Figure 14 is a side elevation of the cable, showing a portion thereof untwisted so that access may be had to the conductors.

Figure l5 is a diagrammatical View o electrical controlling means for the heating devices.

diagrammatic view of the cirview of one of the Figure 16 is an elevational view of another form of heating device, the lower end of the structure being shown in central, vertical, sectional elevation.

Figure 17 is a central longitudinal section, on an enlarged scale, of one end of the device of Figure 16.

Figure 18 is a sectional View taken on the line 18-18 of Figure 17.

Figure 19 is a sectional view, taken on the line 19M-19, of Figure 17, and

=igure 20 is a sectional View, taken on the line 20-20, of Figure 17.

The method involved in the present invention resides more generally in applying heat at a predetermined temperature and at a given locality in the well, for the purpose of maintaining the oil, or the like, flowing from the well at a predetermined temperature, or substantially at a temperattue which will both prevent congealing of the oil, that is, its paraffin or other contents, and also maintain the oil at a freely flowing state oi iluidity so that tendency of the oil or its constituent parts, parailin or otherwise, to congeal or otherwise become solidified in course of travel from the well will be substantially prevented. In carrying out the method, I prefer to employ electrical resistance units, one or a plurality of the same disposed in groups or in series of groups at the desired levels in the well, that is, at the points at which it is known that the refrigeration effect does occur or is most apt to occur. 1 also einploy, in carrying out the method, in one form of the invention, the standard well pumping rig construction or standard construction of the well where it is not necessary to pump the same, that is, in naturally flowing wells. I also regulate the degree of heat applied so to prevent the undue generation of oil well and also concurrently with, or independently of the degree of heat, change the locality of the application of heat. I nd, Within my experience, that electrical heating units, particularly of a preferred construction hereinafter described in detail, make the best heating means known to me at this time owing to their susceptibility of facile regulation as to temperature and their portability. By portability I mean that the heating elements are readily, either by manual manipulation or convenient mechanical means, capable of elevation or lowering in the well, as desired, and of such construction that while they maybe of a size which might be diflicult for a man to carry, are at least of a size convenient of installation and adjustment in the well.

Referring now more particularly to a structure for carrying out the steps of the method here involved, illustrated in the drawings, and first referring to Figures 1 to 3, it will be observed that the conventional outer casing 15 is shown which may be lowered to as great a depth as 2100 feet. Within the casing 15 the conventional socalled inner casing 16 is installed and may be lowered to a depth of 2850 or more feet.

For pumping the well or otherwise recovering the contents thereof, the conventional tubing 17 is installed extending to the bottom of the well, that to the part indicated at A in Figure 1 and A in Figure 3 and known as the oil bearing sands or formation, this tubing having on its lower end a part 18 commonly known as working barrel, within which a plunger 19 of the conventional form and a check valve 20 of the conventional form are installed for operation. The tubing 17 extends through the top of the Well and is provided with a suitable cap 21 connected to a pipe 22 which leads to a suitable tank, not shown.

In many pumping installations in oil wells, the plunger 19 is operated by a flexible cable, and in other installations this plunger is operated by a hollow pipe or rod which, in either event, serve to raise the pipe and the plunger 19, which latter lowers itself by gravity each time to cause iluid to be elevated in the tubing 17.

For convenience in describing, I shall rst refer to the form of the invention in which the tubular pipe is employed and later to the form in which the cable is employed, Figure 1 illustrating the hollow plunger pipe construction and Figures 2 and 3 illustrating the cable construction, which latter, for my purposes, is modified as hereinafter described. The pipe in Figure l is indicated at 23 and the cable in Figures 2 and 3 is indicated at 24.

Referring now in detail to Figure 1, it will be observed that the pump rod or pipe 23 is connected to the plunger 19 and extends upwardly through the cap 2l and through a suitable packing and gland construction 26, the upper end of the pump rod or pipe 23 having a coupling member 23a. A walking beam 27 is mounted upon a Samson post 28 for rocking movement, and the inner end of said beam is connected to the pump rod 23 by the provision of a clamp 29 generally employed and encircling said rod below the coupling, and by a flexible loop 26 having its bight engaging over the beam 27 and its ends xedly connected to the opposite sides of the clamp 29.

The gures of the drawings are, of course, largely schematic and any other convenient constructional pumping outfit.

The outer end of the walking beam is adjustably connected by a pitman 30 to a shaft 3l driven through a belt 30a from a steam engine or other prime mover not shown and passing over the wheel 30h fixed on said shaft. The shaft 30 may be equipped with a sheave 32, and a exible cable 33a passes over said sheave for driving the It will be understood that being discharged, and that upon each upward movement of the plunger, oil is caused to flow out of the discharge into the tank. However, in the drilling of the well it is not unusual to pass through gas bearing formations before reaching the oil such being indicated at B in Figures 1 to 3 this gas bearingr formation being reached in the neighborhood of 2300 feet or at some other distance relatively close to the oil bearing sands. It has been found in practice that the pressure of the gas in these gas bearing formations produces about the tubing 17 what I term a refrigeration action, that is, an action at this locality in the well which causes the oil or its paraffin or other congealable constituents to be increased in viscosity and to even, in many cases, actually congeal, thereby materially hampering the operation of recovery of the oil whether in a well having a natural flow or in a Well from which the oil is pumped. It will be understood that the oil, when it leaves the oil bearing sands at the bottom of the well, has a temperature which maintains the oil in a state of fluidity making it flow quite readily, and while this invention is applicable, in certain respects, to maintaining the temperature of the Oil throughout the well at a predetermined degree and, consequently, maintaining the oil at a desired fiuidity suitable for its ready recovery, it is found that this refrigeration of the oil, or its paraffin or other constituents, takes place most often adjacent to the gas bearing formations, and the present structure is illustrated more particularly for the treatment of the oil at or near such formations for the purpose of maintaining the oil at a desired temperature and fluidity.

'Io this end I provide the Lcable 33 which, in the present instance, is an armored electrical cable containing suitable electrical conductors properly insulated for conducting current, subject to the desired regulation, to one or a plurality of heating units 34, 34 secured to or forming a part of the cable. The detailed construction of` the heating units, so far as the form which may be adopted. is subject, of course, to variation, but this heating apparatus may incorporate a structure such as shown in Figures 4 to 14, that is, the heating units may be incorporated in the cable as a part thereof or may be detachably or otherwise secured to said cable to permit of their insertion as one or a plurality, as found best to suit the purposes.

The cable 33 passes through a snatch block 35 and down through the pump rod or pipe 23, carrying the heating units 34 downwardly in said pump rod or pipe to the desired locality in the well. The snatch block is secured as at 36 in desired manner to the walking beam 27. For raising and lowering the heating units, the cable 33 is wound upona portable drum 33e secured to the Samson post, and thus the heating units may be raised and lowered as a group in the well.

The temperature resulting from the heating units employed may be regulated by regulating the current supply to said heating units or by forming the cable 33 with the required number of conductors which will permit of one or more of the heating units to be placed in operation as desired. Such an arrangement is shown in Figure l5 wherein the heating units are connected oy one conductor 34a to one side of a source of current, not shown, and by a plurality of conductors 35a through a switch 36e to the other side of the source of current so that one, two or three of the heating units may be operating simultaneously.

It will be observed that in the operation of the device thus far described, I am enabled to apply heat to the contents of the well at a desired locality and to a desired degree, that is, 0f such degree that the oil or other product of the well will be, during its recovery from the well, maintained at a desired fluidity suitable to its ready recovery and thus preventing congealing of the product and resulting in putting the well out of operation. The method and the device are, it will be understood, adapted for convenient installation in a well which is naturally flowing, merely by equipping the standard closing cap of the well with a suitable gland and packing such as at 26 to permit the cable to enter into the well. I desire to emphasize the fact that it is not the intention and purpose of my invention to create oil well gases or to in any way change the mechanical or chemical constituents of the oil by the application of heat because I do not preferably employ heat in such a degree as will cause such disturbances of the product, though in same instances the application of heat to attain the desired result may cause a condition of gasifying that part of the product which is closest to the heaters when the device is introduced into a well which has already become congealed.

Another of the advantages of the form of this invention shown in Figure l is that the operator is apprised at all times of the depth at which the heating elements are located by virtue of this knowledge of the amount of cable paid out from the winding drum. This is also true of the other forms of this invention.

Referring in detail to Figures 2 and 3, it will be observed here the cable forms a part of the standard well equipment, that is, instead of the ordnary cable being employed, I substitute a cable according to my invention having thereon the heating units which form substantially a part of the cable.

In the form of the invention shown in Figure l, the heating units are maintained substantially out of direct contact with the contents of the well, whereas, as will be observed from Figures 2 and 3, the heating units are in contact with the product of the well. In either event the aim of the invention is to maintain the product of the well at a temperature and at a fluidity which will render its recovery more readily accomplished without interruption due to causes such as congealing, thickening and the like.

Referring now more particularly to Figure 3, wherein the device of this invention is incorporated in the pumping cable itself, and referring to Figures 4 to 14 which illustrate the details of this form of the invention, it will be understood that a conventional pumping cable, as employed in the oil well industry, is a steel wire cable and includes an inner core formed of hemp or `other fibrous material and around this core is wound a metallic covering 0f steel wire.

Referring first to Figure 2, the walking beam g 27 and associated driving mechanism and bull wheel mechanism 33h is shown, the cable 24 here being fixedly secured as at 27e to a stirrup or clamp 27d which engages over the walking beam. The cable is then passed up over the crown block and extends with slack portions 51 and 52 to the bull wheel 33h.

In this form of invention the heating elements 25a being formed as a part of the cable 24, it is desirable, of course, that the stuffing box 53 be formed so as to be capable of removal from the outlet 21 and of sufficient internal diameter to permit of removal of the stuffing box from the cable without interference byheating elements 25a.

As shown in Figure 3, in a deep well, that is a well going to a depth from 3,000 to 5,000 feet, the gas bearing formations will be encountered at depths fairly close to the depth at which oil is struck. In Figure 3 a well which has been drilled to 2850 feet is illustrated, the gas bearing formations being encountered at about the 2300 foot level. The action of the pressure and temperature of these gases, as hereinbefore pointed out, upon the casing 16 has the effect of producing the refrigeration temperature referred to, and while this condition is ordinarily more severe in the lower portion or level of the well, it may extend through substantially the entire depth of the well.

CII

The steel wire cable referred to above is designated 24, having an inner core 24a formed of hemp or the like and around which the steel Wire 24h is spirally wound. In the practice of my present invention, as illustrated in the details 0f one form thereof in Figures 4 to 14, I employ a steel wire cable of the type referred to but arrange insulated electrical conductors 24e within said inner core which encloses and protects the conductors from injury by the steel wire.

I provide any suitable number of electrical heating devices which are mounted upon the cable 24, at suitable elevations. Each electrical device 25a embodies a pair of double-walled casing sections 26h, which are substantially semicircular in cross section for convenience, and when assembled, produce a substantially cylindrical casing. These casing sections embody outer and inner walls 27a and 28a. The inner walls 28a are continued in straight radial faces 29a, which are adapted to contact, as shown. The outer walls 27a are provided with recesses or depressions 30a, the walls 29a constituting the bottom of these depressions, and these walls are detachably connected by bolts 31a or the like. The walls 28a are provided with .longitudinally extending sockets 32u, adjacent to the inner edges of the faces 29a, and these sockets receive longitudinal packing 33a, which prevents the oil from passing into the interior of the casing, between the faces 29a. Adjacent to their opposite ends, the casing sections 26h have horizontal sockets 34h, which, when assembled, constitute annular sockets, for the reception of packing rings or gaskets, 35h, which prevent the oil from entering the ends of the casing. The bolts 31a serve to clamp the casing sections together and also to clamp them to the cable.

The inner wall 23a of each casing section has its material bent outwardly, forming a terminal box 36a, having openings formed therein for receiving binding posts 37. Arranged within each space 2713 of the casing sections, is an electrical heat resistance element 38, including a coil 39, wound upon a curved insulating support 40, formed of mica or the like. A curved insulated sheet 41 formed of mica or the like is arranged outwardly of the resistance element and a similar curved insulated sheet 42 is arranged upon the inner side of the resistance element. The space provided by the terminal box 36 may be filled with asbestos 43 or the like. One end of the resistance coil 39 is connected with the wire 44, which is connected with the outer end of one binding post 37, and the opposite end of the resistance coil 39 is connected with a wire 45, which is connected with the outer end of the other binding post.

The cable 2lb is manufactured in the usual manner, excepting that the insulated conductors 24e are imbedded within the fibrous core 24a. When it is desired to connect my heating device with these conductors, the cable is engaged at suitably spaced points with tongs or grips 46,

which are turned in the direction to unwind the strands o! the cable, somewhat as illustrated in Figure 14. When in this condition, access may be had to the core 24a and to the conductors 24o. The insulation is removed from the conductors at suitable points, and armored insulation branch wires 47 are electrically connected with these conductors, and the joints are preferably Wrapped or insulated, and the conductors are returned to the imbedded position in the core. When the grips 46 are rotated in an opposite direction to wind or permit of the winding action of the wire strands of the cable, these strands will return to the normal twisted position and the armored branch wires 47 will project between the strands of the cable, as indicated in Figure '7. As there are two heating units in each device, two pairs oi' branch wires are provided, at each point, the upper branch wires preferably being connected with one insulated cable and the lower branch wires with the other insulated cable. The outer ends of these branch wires 47 are now secured to the inner ends of the binding posts.

The operation of the apparatus is as follows:

The cable 24 is employed to raise the plunger 19, in, the reciprocation of the plunger, as is well known. In addition to this function, the cable constitutes the support for the electrical heating device or devices, and also as the carrier for the electrical conductors. As clearly shown in Figure 4a, the current is supplied downwardly through the positive conductor 24 and will pass through the resistance elements 39 and will return to the negative conductor 24e. In this manner, current is supplied to the resistance elements in each heating device and the heat will be transmitted through the outer Wall 27a, heating the oil within the tubing 17 and the heat will in turn, be transmitted through the tubing 17 to the interior of the casing 16, to heat the oil therein, and overcome the effect of refrigeration produced by the pressure and temperature of the gases acting upon the casing 16. I have shown a number of heating devices applied to the cable and I Wish it understood that the invention is in no sense restricted to any particular number or arrangement of these heating devices as the same may be widely varied, as required by working conditions.

It will be obvious that the structure shown in Figures 4 to 14 may be employed in the hollow plunger rod or pipe 23 shown in Figure l, and, furthermore, that the structure of Figures 4 to 14 may be employed in a owing well, that is, a well in which the recovery of oil takes place by the natural forces exerted within the well upon its contents. It will be obvious that any other convenient arrangement of the heating elements on the cable may be resorted to without departure from the import of the invention, and that these heating units may, if desired, be incorporated in a pipe line or a storage tank for preventing the formation therein of paraiiin or other deposits due to refrigeration or other effects tending to solidify the oil or its constituents.

Referring now more particularly to the form of the heater device shown in Figures 16 to 20, it will be observed that here, too, the temperature resulting from the heating iuiits may be regulated by regulating the current supply to said heating units or by forming the cable 33 with the required number of conductors which will permit of one or more of the heating units to be placed in op eration as desired. The arrangement shown in Figure 15, above described, may be employed for this purpose.

While any desired number of the heater units, such as are shown in Figure 16, may be employed, as will be readily understood, it wiil be suilicient for my present purposes to proceed with the description of one of them, with the understanding that any desired number may be connected in series parallel.

Referring now more particularly to Figure 17, it will be noted that in the form of device here shown the heating is performed by one or more resistance coils helicall'y wound about a shell 51 which may be composed of mica or other suitable material whereby said coil 5i) is insulated from the supporting member here shown as the pipe 52. The pipe 52 in the :form here shown is provided with a terminal 53 into which the conductor 5e is introduced, and the structure thus far described is contained within a casing 55 and insulated therefrom by suitable cement 56 and annular insulators 57, as indicated, the latter also serving as spacing elements. This casing 55 is provided with a terminal 58 and has aflixed theretc the return conductor 59, a collar 6G, which may be of hard nbre or other suitable material, being employed to separate the pipe 52 and the casing The coil 55 is attached at one end, as indicated at 6l, to the pipe 52 which thus serves as a feed conductor, and said coil is attached at the opposite end to the casing 55, as indicated at 62 (Figure 1G) which thus serves as a return conductor.

It will be understood that the conductors 54 and 59 may be wrapped to form a single supply cable such as is indicated at 24, and that they should be oi suiiicient mechanical strength to serve as supporting means for such a number of the structures of Figure 16 as may be used in forming the desired equipment of heater devices for the system.

Having thus described my invention and illustra-ted its use, what I claim as new, and desire to secure by Letters Patent is:

1. A well, a reciprocatory element for operating the plunger in the working barrel, an electrical heating element mounted within the reciprocatory element, and conductor or conductors enclcsed by the reciprocatory element and having electrical connections with the electrical heating element.

2. The combination with a well, a working barrel and a plunger in the werking barrel, of a cable connected to the plunger embodying a core and metal strands twisted about the same, conductor or conductors imbedded within the core and an electrical heating device mounted upon the cable and having electrical connection with the conductor or conductors.

3. In combination, a cable adapted for operating the plunger in the working barrel of an oil well, said cable embodying a fibrous core and metal strands twisted about the same, conductor or conductors imbedded within the iibrous core, and an electrical heating device mounted upon the cable and having electrical connection with the conductor or conductors.

4. In combination, a cable adapted for operating the plunger in the working barrel of an oil well, an electrical heating device mounted upon the cable including a casing formed in separable casing sections adapted to enclose the cable, means for connecting the casing sections, resistance elements mounted in the casing sections, conductors carried by the cable, and means for connecting the conductors with the resistance elements.

5. In combination, a cable adapted for operating the plunger in the working barrel of an oil well, casing sections surrounding the cable, means to clamp the casing sections to the cable, resistance elements within the casing sections, conductor or conductors extending longitudinally ci the cable, and means to electrically connect the conductor or conductors with the resistance elements.

6. In combination, a cable adapted for operating the plunger in the working barrel of an oil well, a casing surrounding the cable and movable with it, a resistance element within the casing, conductor or conductors extending longitudinally ci the cable, and means to electrically connect the conductor or conductors with the resistance element.

7. In combination, a cable adapted for operating the plunger in the working barrel of an oil well, doubleuwalled casing sections adapted when assembled to surround the cable, means to clamp the casing sections to the cable, resistance elements within 'the double-walled casing sections, and means to supply the current to the resistance elements.

HOWARD H. FITZPATRICK.

Images