US2747511A - Deep well pump - Google Patents

Description

May 29, 1956 M. c. TURNER 5TM.

DEEP WELL PUMP Filed Nov.

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DEEP WELL PUMP Marshall C. Turner and Theodore Miles, Long Beach,

Calif., assignors to Phillips Petroleum Company, a corporation of Delaware Application November 25, 1952, Serial No. 322,444

6 Claims. (Cl. 10S-46) This invention relates to oil well pumps. In one aspeet it relates to an oil well pump not requiring use of rotating parts. In another aspect it relates to oil well pumps employing a reciprocating column of liquid to operate a pump piston. In still another aspect it relates to deep well pumps.

Conventional oil well pumps require either a sucker rod for actuating the piston of areciprocating pump or a owing column of liquid or gas under pressure. In the type of pump employing gas or liquid the exhausted gas or liquid is usually added to the production liquid for disposal.

In the pump assembly of our invention we employ a reciprocating column of liquid to impart a reciprocating movement to a pump plunger. In this manner only a very limited amount of liquid need ever be used for actuating the pump. The same liquid as is being pumped or any other desirable liquid may be used as a power liquid since it is not added to the oil being pumped.

An object of our invention is to devise an oil well pump having no rotating parts for use in deep wells.

Another object of our invention is to devise an oil well pump requiring a minimum of power for its operation.

Still another object of our invention is to provide an oil well pump having a minimum number of moving parts.

Yet another object of our invention is to provide an oil well pump which is actuated by a liquid under pressure but which requires only a very small volume of pressure liquid.

Yet other objects and advantages of our invention will be realized upon reading the following description which combined with the attached drawing forms a part of this specification.

Our pump is built and operated on the principle of utilizinga rigid assembly of several pistons of dilerent areas, in which the upstroke of the piston assembly is powered by a pressure liquid and the downstroke is powered by the force imparted by the column of production oil imparted to the piston having a relatively large area.

In the drawing, Figure l is a longitudinal view, partly in section, of one embodiment of my invention. Figure 2 illustrates this apparatus in a deep well. Figures 3 and 4 illustrate additional embodiments of my invention,

Referring now to the drawing and specilcally to Figure l, the pump assembly ot' our invention is mounted on or in the lower end ot a conventional production tubing. In Figure 1 we illustrate our pump apparatus as being attached to the lower end of a production tubing 11. The pump is enclosed in a large diameter tube which is held to the tubing 11 by a bushing 12. Near the lower end of this large diameter tube 15 are a number of openings 17 for admission of oil from the well bore to the pump inlet. Within this tube 15 is attached a pump case 16 by threads 14 orby other means, not shown. This pump case 16 constitutes three cylinders of different diameters. These cylinders include an upper cylinder 18 of largev diameter, a next lower cylinder 20 of intermediate diameter Patented May 29, 1956 and a small diameter bottom cylinder 22. Fitted into these cylinders is a piston assembly composed of a large diameter piston 19, an intermediate diameter piston 21 and a small diameter piston 23. At the bottom of the small diameter cylinder 22 is provided a conventional ball valve 24. Along the axis of the piston assembly is provided a conduit 26 containing a ball valve 25 at a point near its lower end. The ball valve 24 is intended to permit the flow of oil from the space outside of the small diameter cylinder 22 into a space 33 inside cylinder 22. Ball valve 25 allows oil flow from the space 33 to conduit 26.

At the lower end of the large diameter cylinder section 19 are provided vents 31 for inflow and outflow of oil as the piston raises and lowers during its operation.

When the piston assembly is in a raised position an annular space 30 is for-med below the large diameter piston section 19 and around the piston of intermediate diameter. In like manner an annular space 32 is formed below the intermediate diameter piston and around the small diameter piston 33. In this latter annular space 32 the power liquid is forced under pressure for raising the piston assembly. The power liquid enters this annular space 32 from a tube and conduit assembly which includes a tube 27 disposed in the oil production tubing 11, a horizontal conduit 28 in the head of the cylinder assembly 16, one or more vertical passageways 29 in the wall of the large diameter cylinder section 1S, and one or more tubes 13. In the head of the large diameter cylinder section 18 is provided openings 34 t'or the outilow of production liquid from the pump apparatus to the production tubing 11.

In the operation of this pump, the upstroke of the pis-v ton assembly draws oil through ball valve 24 into the space 33. At the same time oil on top of piston 19 is forced through openings 34 into the production tubing 11 for transmission up the tubing. On the downstroke of the piston the ball valve 24 closes and the ball valve 25 opens and the oil in space 33 ows upward through conduit 26 into the space above piston 19. As far as production oil is concerned these several operational steps complete the cycle.

To actuate the piston it is merely necessary to exert pressure at the surface of the ground on the oil in tube 27. This pressure is transmitted down tube 27 and is transmitted through conduits 28, 29 and 13 into the annular space 32 under the piston 21. When sutcient pressure is exerted on the oil in tube 27 the entire piston assembly raises and forces oil from the space on top of piston 19 through openings 34 into the production tubing 11. After the piston assembly reaches the top of its stroke the pressure imparted to the oil in tube 27 is released and the piston assembly is forced downward due to a diiferential of force acting on the piston assembly.

The forces tending to move this piston assembly upward and downward are tabulated and identified as follows:

Di=total downward force of production liquid on the circular head of piston 19.

Uimhe upward force of the oil well liquid acting The forces tending to move this piston assembly upagainst the annular surface 35 on the bottom side of the large diameter piston 19.

Uz=the upward force of the power liquid acting against the annular surface 36 at the lower end of the intermediate diameter piston 21. This force U2 is composed of the sum of two forces H1 due to the static head of power liquid between the surface 36 and the top of the ground, and P1, the force exerted on the power liquid by a power pump at the surface of the ground.

Uahe force of the oil well liquid exerted on the bottom of the small diameter piston 23 acting only on the upstroke of the piston assembly.

Uli'ue force of the production liquid from the production tubing 11 and conduit 26 exerted upward against the surface of the small diameter piston 23 only on the downstroke of the piston assembly. Y

When the sum of the forces U1, U2, and U3 is greater than D1 the piston moves upward on a pumping stroke and when D1 is greater than the sum of the forces U1, H1 and U4, and the piston moves on a downstroke.

When the piston moves on a downstroke the pressure liquid in the annular space 32 is forced through tubes 13 and conduits 29 and 28 into conduit 27; On the power stroke of the piston, that is its upward stroke, power liquid from tube 27 flows through conduits 28 and 29 and tubes 13 into the space 32 to raise the piston. The volume of power liquid introduced into the annular space 32 is relatively small in comparison to the volume of power liquid in the tubing 27. Also this volume of power liquid in space 32 is used over and over again. In this manner the power liquid which isY utilized in operating 'our pump need not be pumped to the surface of the Power to drive our pump is supplied by increasing the n pressure on the power liquid in tube 27. The amount of pressure required is determined by the ratio of area 36 to area 19, the ratio of well pressure to the pressure of the head of fluid in tubing 11, and the ratio of specilic gravity of power liquid to the specific gravity of production fluid.

By providing annular surface 3S', our pump is made Yto operate on the down stroke without such an auxiliary device as a spring or a gas powered cylinder. By properly choosing the area of the annular surface 35, it is possible to provide that force D1 is greater than the sum of forces U1, H1 and U4, and when the pressure is reduced on the power liquid in tube 27, the piston assembly will travel downward. An analysis of these forces follows: D1=area of piston 19 times the static pressure I of the column of production fluid in tubing 11. H1=area of annular surface 36 times the static pressure of the column of power liquid. U4l=area of surface 37 times the pressure `of the column of production uid in tubing 11 (ball valve 25 is open on down stroke).` U1=area of annular surface 35 times the well pressure. When the specific gravity of the power liquid is equal to the specic gravity of the production fluid, the net downward force equals the area of annular space 35 times they difference between the pressure of the production lluid in tubing 11 and the well pressure. For a given set of conditions, annular space 35 can be sized to provide a desired net downward force.

The pump assembly illustrated in Figure l of the drawingV is of relatively large diameter and is adapted to pump a relatively large volume of oil on each stroke. In Figure 3 of the drawing is illustrated a pump assembly similar to that of Figure l but which assembly is of a suciently small diameter to be mounted and operated inside of a yconventional string of tubing, such as tubing 11 and Figure l. Referring to Figure 3 tubing 61 is as indicated a tubing similar totubing 11 of Figure l. Mounted on the bottom end of tubing 61 is a collar or coupling 63 having a small beveled surface 67 at the position indicated along the inner surface. The upper section ofthe large diameter cylindrical portion of the pump 65 is also provided with a beveled portion containing grooves and O-rings seals 66 for sealing the space in the tubing 61 above these beveled portions from the space below. This sealing is necessary because if it were not provided oil would be pumped upward through the pump 65 into the tubing 61 and this oil would merely flow Vdownward and pass between the pump and collar back into the bottcm of the Well. By providing these seals 66 as the oil is pumped through the pump into the tubing 61 static pressure is exerted against the seals 66 and as the pressure becomes larger the sealing effect becomes greater thereby not permitting flow of pumped oil from tubing 61 downward around the pump toward the bottom of the well. Tube 64 is for accommodation of power liquid tlowiug into aud out of the pump 65. Other than thisV sealing means 67 the pump 65 is illustrated diagrammatically in Figure 3 may be exactly like the pump illustrated in greater detail in Figure l.

Figure 4 illustrates a variation of my invention in which a tube 75 for carrying the power liquid is positioned outside of a production tubing 71 in place of inside of the production tubing as illustrated in Figures l and 3. In the embodiment of Figure 4 since the power liquid is introduced into the intermediate diameter power cylinder as illustrated this pump 74 need not be provided with such conduits as conduits 2S and 2i) o f Figure l. The pump illustrated in Figure 4 is sealed to the tubing string to prevent back llow of pumped oil by threading same to a collar 73. This threaded joint is identified byreference numeral 76. To the bottom end of collar 73 is attached a protective tubing 72 which preferably contains some openings similar to opening 17 Figure l, and not shown in Figure 4, for admission of oil to the pump.

In Figure 2 is illustrated an assembly of pumping apparatus in an oil well containing oil 58. In this ligure the surface of the ground at the well head is identified by reference numeral 51. The well is protected yby a casing 52. Disposed down the casing is a production tubing 55 carrying a pump assembly 57 of our invention. Disposed within the tubing 55 is a small diameter tube 56 for accommodation of the power liquid. A pipe 53 is connected to the casing at the well head for withdrawal of gas or for any -other purposes desired. A pipe 54 leads from the top of the tubing string 55 to oil storage tanks not shown.

The pistons of several diameters of our invention are of course provided with rings or other sealing means to provide fluid-tight piston operation. The relative diameter of the three piston sections are so chosen that the static head of the production liquid in tubing 11 of Figure l forces the piston downward on its intake stroke and so that the power pump pressure applied to the power liquid at the well head need not be excessively great. The maximum diameter of pump assembly will be determined by whether the pump is to be used inside of a string of tubing of conventional size or Whether it is to be used on they end of a tubing string. In this latter case it will be necessary to mount the pump within the pipe 15 of Figure l and install this assembly by means of a conv necting element such as bushing 12 to a section of tubing such as tubing 11 and then lowering this pumping assembly into the well by merely adding successive sections of power tubing 27 and production tubing 11.

If the pump assembly as illustrated in Figure 3 is used, it is merely necessary t-o assemble the protective tubing 62, the coupling 63 on the bottom of the production tubing 61 and then to run the production tubing into the well. The pump 65 containing the 0-rings in their proper grooves is then run down the tubing by adding successive sections or joints of theV power liquid tubing 64.

The pumping apparatus of Figure 4, as regards the protective tubing 72, the collar 73, the pump 74 will need to be assembled at the well head. This assembly is then lowered into the well by adding successive joints of production tubing 71 and power liquid tube 75.

The materials of construction used in manufacturing pumps of our invention may be selected from among those commercially available taking into consideration the corrosive nature of the oill and the like.

While certain vembodiments of our invention have been described for illustrative purposes the invention is obviously not limited thereto.

We claim:

l. In a liquid powered oil well pumping assembly of the character described, a stationary oil ow tubing disposed in an oil well, a pump case disposed huid-tight in the lower end of said ow tubing, said pump case having an upper and large diameter cylinder, a bottom and small diameter cylinder and a cylinder of intermediate diameter disposed rigidly to 'and between said large diameter cylinder and said small diameter cylinder, la reciprocating piston element in said case comprising a large diameter piston, a small diameter piston, and an intermediate diameter piston disposed rigidly therebetween, the three pistons being disposed operatively in the three corresponding cylinders, said cylinders and said pistons disposed along a common axis, a tubular opening along the axis of said piston element, a valve in the lower end of said tubular opening adapted to pass production oil upward, a second valve in the lower end of the small diameter cylinder and below said iirst valve, said second valve being adapted to pass production oil into said small diameter cylinder, sealing means intermediate the large diameter cylinder and the oil flow tubing to prevent leakage of production oil therebetween, and a tube means communicating with the intermediate diameter cylinder at a level below said intermediate diameter piston at the bottom end of its stroke for introduction of power liquid to lift said reciprocating element and force production oil upward in said oil ow tubing and for exhausting power liquid therefrom at such time as the liuid pressure in said oil ow tubing forces said piston element downward on its return stroke.

2. In a liquid powered oil well pumping assembly of the character described, an oil flow tubing disposed in an oil well, a pump case disposed huid-tight in the lower end of and with respect to said ow tubing, said pump case having three cylinders of successively diminishing diameters, a rigid piston assembly having three pistons of successively diminishing diameters, said three pistons operatively fitting respectively in said three cylinders, said three cylinders and pistons disposed along a common axis, a conduit extending throughout the length of said piston assembly, a rst valve in the lowest and smallest diameter cylinder for admission of production oil into this cylinder, a second valve in said conduit and above said first valve, said second valve being adapted to pass production liquid from said smallest diameter cylinder to the cylinder of largest diameter, and a tube communicating with the intermediate diameter cylinder at a level below the intermediate diameter piston at the bottom end of its stroke for introduction of power liquid to lift said reciprocating element and force production of oil upward in said oil flow tubing and for exhausting power liquid therefrom Iat such time as the iluid pressure in said oil ow tubing forces said piston element downward on its return stroke.

3. ln an oil well pumping assembly of the character described, the combination comprising a production oil ow tubing extending down an oil well, a tube of larger diameter than the diameter of said oil ilow tubing being attached liquid-tight to the lower end of said oil ow tubing, a pump case disposed in the larger diameter tube, the upper end of said pump case being adapted to discharge production oil into said flow tubing, said pump case comprising an upper large diameter pump cylinder, a second smaller diameter power cylinder rigidly attached to and disposed below said large diameter cylinder, a third and still smaller diameter oil pump cylinder rigidiy attached to and disposed below said second cylinder, a multiple piston assembly comprising three pistons of diameters to t operatively said three cylinders, said three cylinders and said three pistons diposed along ia common axis, a conduit disposed along the axis of said piston assembly, a first valve in said conduit for passing production oil from the small diameter cylinder to the large diameter cylinder upon the downstroke of said piston assembly, ta second valve below said iirst valve in said small diameter cylinder for admission of production oil into the small diameter cylinder upon the upstroke of said piston assembly, sealing means intermediate the large diameter cylinder section of said pump case fand said larger diameter tube to prevent leakage of production oil therebetween, a tube communicating with the power cylinder at a level below its piston at the bottom end of its stroke for introducing power liquid to said power cylinder to raise said piston assembly to force production oil up said ow tubing and to draw production oil into said small diameter cylinder and to exhaust said power liquid from said power cylinder at such time as the fluid pressure in said oil ow tubing forces said piston assembly .downward and thereby forcing production oil from said small diameter cylinder through said conduit into said large diameter cylinder.

4. An oil well pump comprising, in combination, a rigid pump case of circular cross section and having both ends closed, said case comprising three cylinders of unequal diameters, said three cylinders being arranged in order of increasing diameters, a rigid piston assembly comprising three pistons disposed operatively in the three corresponding cylinders, a conduit along the axis of said piston assembly, ya valve in said conduit adapted to pass liquid in the direction from the small vdiameter piston to the large diameter piston, a valve in the lower end of the small diameter cylinder adapted to pass liquid into the small diameter cylinder, at least one opening in the closed end of the largest diameter cylinder for outlet of production oil, an opening in the end of the largest diameter cylinder nearest the cylinder of intermediate diameter for breathing during movement of the piston assembly relative to said case, an opening at the end of the cylinder of intermediate diameter closest to the cylinder of small diameter for inlet of power liquid to raise said piston assembly on its power stroke, a cylindrical casing open at both ends surrounding said pump case, and means for sealing said cylindrical casing Huid-tight to the large diameter cylindrical section of said pump case.

5. ln a deep well liquid powered pumping assembly of the character described, a production liquid flow tubing disposed in a deep well, a pump case disposed Huid-tight in the lower end of and with respect to said flow tubing, said pump case having three cylinders of different diameters, said cylinders being arranged in order of decreasing diameters from top to bottom, a rigid piston assembly having three pistons, said pistons fitting operatively into the corresponding cylinders, said cylinders disposed along a common axis, a conduit disposed axially throughout the length of said piston assembly, a valve in the lower and smallest diameter cylinder for admission of production liquid from the well into this cylinder, a valve in said conduit for passing production liquid from said small diameter cylinder to the large diameter cylinder on downstroke of the piston assembly, at least one opening in the closed end of the large diameter cylinder for communication between the space above the large diameter piston with the liquid ow tubing for outlet of production oil and for inlet of production oil to return the piston assembly to the lower end of its stroke, means for forcing power liquid from a power liquid tubing extending up the well into the cylinder of intermediate diameter to force the piston upward on its pumping stroke and means for admitting the power Iliquid from said cylinder of intermediate diameter into said power liquid tubing in 'a pulsating manner.

6. In a liquid powered oil well pumping assembly of the character described, a stationary oil liow tubing disposed in an oil well, a tube having a larger diameter than that of said oil ow tubing being attached liquid-tight to the lower end of said oil flow tubing, a pump case disposed 7 in the larger diameter tube, Said pump case having, an upper and larger diameter cylinder, a bottom and, small diameter cylinder and a cylinder of intermediate diameter disposed rigidly to and between said large diameter cylinder and said small diameter cylinder, a reciprocating piston element in said case comprising a large diameter piston, Aa smallV diameter piston, and an intermediate diameter. piston disposed rigidly therebetween, said three pistons being disposed operatively in the three corresponding cylinders, said cylinders and said pistons being disposed along a common axis, a tubular opening along the axis of said piston element, a valve in said tubular opening 'adapted to pass production oil upward, a second valve kin the. lower endsof the small diameter adapted to pass production oil into said small diameter cylinder, sealing means intermediate theV large diameter cylinderl section of said pump ease and said larger diameter tube to prevent leakage of production oil therebetweem'and a tube communicating with the intermediate diameter cylinder for' introduction of power liquid to lift said reciprocating element and force production oil upward in said oil ow tubing and for exhausting power liquid therefrom at such,

time the fluid pressure in said oil flow tubingV forces said piston element downward on its return stroke.

ReferencesV Cited in the le of this patent UNITED STATES PATENTS

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