US2817298A

US2817298A - Well pump

Info

Publication number: US2817298A
Application number: US520987A
Authority: US
Inventors: Peter S Bloudoff
Original assignee: AXELSON Manufacturing Co
Current assignee: AXELSON Manufacturing Co
Priority date: 1955-07-11
Filing date: 1955-07-11
Publication date: 1957-12-24
Anticipated expiration: 1974-12-24

Description

Dec., 24, 195? P. s. BLoUDoH-F 2,817,298

WELL PUMP Filed July 1l, 1955 2 Sheets-Sheet l waarin .s

Filed July l1, 1955 P. s. BLouDol-F 2,81 '7,298

2 Sheets-Sheet 2 INVENToR. sre/a 5. www? '2,8 l 7,298 Patented Dec. 24, 1957 ice WELL PUMP Peter S. Bloudoff, South Gate, Calif.,

Manufacturing Company, poration of Delaware assignor to Axelson Los Angeles, Calif., a cor- The present invention relates generally to pumps and more particularly to a novel and improved reciprocating pump especially adapted for use in pumping fluid from well bores.

In pumping fluids such as oil and water from a comparatively deep well bore a single stroke reciprocating well pump connected to the surface by a string of sucker rods is generally employed. With such pumps the volume of well Huid which is pumped during a pumping stroke is dependent upon the length of the stroke and the number of strokes per minute. Both of these factors are restricted by mechanical and economical limitations, in that the length of the pump stroke is dependent upon the size and cost of the surface-located power means, while the number of strokes per minute cannot exceed a certain gure without causing undue wear and consequent damage to the sucker rods, pumps and other equipment.

In order to overcome the disadyantages of the aforedescribed conventional well pump having but a single pumping chamber, it has heretofore been proposed to provide a single pump having two vertically spaced pumping chambers from each of which chambers fluid is con currently displaced during a single upward or downward stroke. These pumps are commonly termed double volume pumps. Although these double `volume pumps have proven to be generally satisfactory in use, inasmuch as both the lower and the upper chambers must be lled simultaneously from the lower Iend of the pump some difficulty has been experienced in completely filling the upper of the two pumping chambers duiing the intake stroke. Additionally, because of the comparatively long length of these double volume pumps the moving member of the pump tends to buckle from compressive forces during a downstroke. This tendency to buckle causes certain parts of the pump to undergo rapid wear resulting in a comparatively short service life for the pump. T he cost of removing and reinstalling a pump located in a deep well is considerable.

:It is a major object of the present invention to provide an improved form of single-acting double volume well pump.

yIt is another obiect of the invention to provide a double volume well pump wherein both the upper and lower pumping chambers are completely filled during an in take stroke.

yIt is a further object to provide a pump of the aforedescribed nature wherein the vertical span between the various bearing surfaces of the pump has been appreciably shortened so as to reduce the tendency of the moving pump member to buckle during a downstroke.

Another object is to provide a single-acting double volume well pump which is simple of design and rugged of construction whereby it may afford a long and useful service life, requiring but a minimum of maintenance once it has been installed.

A further object of the invention is to provide a double volume well pump wherein the uid pressure acting upon the upper portion of the barrel the various pumping chamber-defining members are equalized during a downstroke. With this arrangement the normal tendency of the sucker rods -to buckle during a downstroke is appreciably reduced.

Yet another object is to provide a single-acting double volume well pump which employs many standard pump parts whereby both its initial and maintenance cost may be reduced to a minimum.

I'It is well known that pumps of the double volume type have a tendency to become unseated from the well tubing. Another important object of the present invention is to provide a unique anchoring means especially adapted for use with a pump of this nature.

These and other objects and advantages of the present invention will become apparent from the following detailed description, when taken in conjunction with the appended drawings, wherein:

Figure l is a central vertical sectional View of the upper portion of a preferred form of double volume well pump embodying the present invention;

Figure 2 is an enlarged `central vertical sectional view of the lower portion of said pump, lFigure 2 forming a downward continuation of Figure 1; and

Figures 3 and 4 are diagrammatic views showing the mode of operation of said well pump.

Referring to the drawings and particularly Figures l and 2 thereof, the preferred form of double volume well pump embodying `the present invention broadly comprises a stationary body member S which is secured at its lower end by a special anchor means A within the well tubing T, and a barrel member B which is vertically reciprocated relative to the stationary body member S by a string of sucker rods. The lowermost of these sucker rods 9 is secured Ito the upper end of the barrel member, while the uppermost is secured to a surface-located power means (not shown). The stationary body member S and the barrel member B cooperate to define an upper pumping chamber U and a lower pumping chamber L. Upon reciprocation of the barrel member B relative to the stationary member S, well fluid is pumped from a point below the anchor means A -upwardly through the interior of the well tubing T to the earths surface.

"More particularly, the stationary body member S includes a cylinder 1li and an upstanding tubular neck 12 of lesser diameter that extends upwardly from the upper end of the cylinder 1l). A hollow upper piston 14 is formed on the upper end of the neck 12. One or more pressure-equalizing ports 15 are formed in the upper portion of the cylinder 1li for establishing communication between its upper portion and the fluid in the lower portion of the tubing T. A standing valve chamber 16 wherein is disposed a downwardly closing ball element 17 is formed at the lower end of the stationary body member S. The lower portion of the body member S is formed with a coaxial inlet passage 18 that empties into the `standing valve chamber 16. The upper end of this standing valve chamber 16 is connected to the lower end of the lower pumping chamber L by a `coaxial open and slidably encompasses the upper piston 14 of the body member S so as to dene an upper pumping chamber U thereabove. The lower end of One or more apertures 3l) are formed in the upper portion of the plunger tube 26 to establish tween the interior of the tube chamber U. A traveling valve posed an upwardly opening ball and the upper pumping cage 32 wherein is diselement 34 is formed on member. The lowermost this cylinder 28 is open.`

communication be@4 sucker rod 9 is threadedly secured to the upper end of the cage 32. A hollow lower piston 36 is slidably disposed within the confines of the lower cylinder 10 so as to define the lower pumping chamber L.

Referring now to Figure 2, the anchor means A includes a mandrel element, generally designated 3S, having its upper end rigidly secured to the lower end of the stationary body member S, a plurality of conventional packer cups 40 carried by this mandrel, a special seating ring 42 also carried by the mandrel 38 and a seating nipple 44 secured to the well tubing and encompassing the major portion of the mandrel 38 and the elements carried thereby.

The mandrel 33 is formed at its upper end with an externally threaded pin 46 which is received by a complementary internally threaded socket 48 coaxially formed in the lower end of the stationary body member S. The mandrel 3S is also formed with a longitudinal bore 50 which defines a lower continuation of the inlet passage 18.

Below the pin 46 the mandrel 38 is formed with a shoulder 52. Below this shoulder 52 the diameter of the mandrel is reduced for receiving the seating ring 42. The diameter of the mandrel is further reduced below the seating `ring 42 for receiving the packer cups 40. A conventional cup nut 54 is threadedly secured to the lower end of the mandrel for retaining both the packer cups and the seating ring 42 in place. ln this regard, the lower end of the seating ring is formed with an end wall 56 having a coaxial bore 58 of slightly greater diameter than the mandrel. The upper surface of this end wall S6 abuts the underside of a collar 60 formed on the mandrel, while the lower surface thereof abuts the top of the uppermost packer cup 40.

The seating ring 42 is preferably formed of brass and its sides 62 taper upwardly and radially outwardly from its end wall 56. The upper portion of the seating ring 42 when not engaged with the interior of the seating nipple 44 is of somewhat greater diameter than the inner diameter of the seating nipple. The seating nipple 44 is preferably formed of steel and its upper end is externally threaded, as indicated at 64, for engagement with thc internally threaded lower end of the well tubing T. When the pump is to be secured in pumping position within the Well tubing, the mandrel 38 is urged downwardly into the confines of the seating nipple 44 until the underside of the mandrels shoulder 52 rests upon the radially inner portion of the upper end of this nipple. Preferably, this portion of the nipple will be formed with a radius 66 complementary to a radius 68 formed on the shoulder. As the mandrel 33 is inserted within the seating nipple the upper portion of the seating ring 42 is squeezed radially inwardly by the inner walls of the nipple whereby it will continuously exert a radially outwardly directed force against these walls. This force serves to lock the seating ring and hence the mandrel 3% against axial movement relative to the seating nipple during operation of the pump. The magnitude of this force is proportional to the thickness of the side Walls of the seating ring. lt is important to observe that the proportions of the seating ring should be so chosen that it does not undergo permanent deformation when it is inserted within the seating nipple. The use of brass for the seating ring and steel for the seating nipple has proven to be preferable inasmuch as it affords the most consistent coefficient of friction, and additionally the modulus of elasticity of brass has been determined to be highly satisfactory. The seating ring may be unseated from the seating nipple merely by exerting suicient upward force upon the mandrel 38 to overcome the frictional resistance of the seating ring.

In the operation of the above-described preferred form of double volume pump embodying the present invention, and referring particularly to Figure 3, during an upstroke of the barrel member B the lower piston 36 will function to enlarge the lower pumping chamber L thereby raising the standing valve ball element 17 and drawing liquid upwardly through the inlet passage 18. Simultaneously, the volume of the upper pumping chamber U will also be enlarged so as to create a suction within the plunger tube 26. During this time the traveling valve ball element 34 will be maintained in a seated position by the pressure of the uid in the well tubing column. Accordingly, well fluid will be concurrently drawn into both the upper and lower pumping chambers from the inlet passage 18. It should be particularly observed that there are no restrictions to fluid ow interposed between the upper end of the inlet passage 18 and the lower pumping chamber L. This is very important inasmuch as sufticient well nid for filling both the uper and lower pumping chambers must pass through the lower chamber during an upstroke. It will also be apparent that the upward movement of the barrel member B serves to raise the column of well fluid located in the well tubing T above the traveling valve 34 towards the earths surface.

Referring now to Figure 4, upon a downstroke of the barrel member B the lower piston 36 will move downwardly so as to reduce the volume of the lower pumping chamber L and thereby displace well huid upwardly through the neck 12, the standing valve ball element 17 being maintained in a seated position during this time. Simultaneously, the volume of the upper pumping chamber U will also be reduced so as to displace well uid therein upwardly through the apertures 30. The upward pressure of the iiuid on the traveling valve ball element 34 will cause this element to be raised. Accordingly, well liuid from both the upper and lower pumping chambers will be urged into the well tubing above the traveling valve ball element 34.

it should be particularly noted that the space within the lower cylinder 10 above the upper surface of the lower piston 36, is at all times in communication with the uid pressure existing within the well tubing by means of the pressure-equalizing ports 15. Likewise, the underside of the upper piston 14 will always exist at the pressure of the well uid inasmuch as the lower end of the upper cylinder 28 is open. Accordingly, during a downstroke of the barrel member fluid pressure along the contacting surfaces betwen the upper piston 14 and the upper cylinder 28 and between the lower piston 36 and the lower cylinder 10 will be equalized. Hence, the sucker rods need overcome only the frictional resistance between the pistons and the cylinders plus the resistance to uid flow through the pump in order to move the barrel member downwardly. It is therefore unnecessary to apply other than a minimum amount of downwardly acting force to the rods. With this arrangement the danger of kinking or otherwise damaging the sucker rods is minimized. It should also be observed that the aforedescribed arrangement provides excellent bearing conditions with regard to the plunger tube 26 so as to reduce the danger of its becoming bent during a downstroke.

The aforedescribed preferred form of double volume pump permits the utilization of many standard pump parts. For this reason, both the initial and maintenance cost of such a pump may be reduced to a minimum. Additionally, this design employs a minimum number of working parts whereby it will afford a long and useful service life without necessitating other than minor maintenance once it has been installed.

Although there has been shown and described hereinabove what is presently considered to be the preferred embodiment of the present invention, it will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the spirit of the invention or the scope of the following claims.

I claim:

l. A well pump, comprising: a body member having a cylinder and a tubular neck extending axially from one end of said cylinder; a hollow piston formed on the end of said neck remote from said cylinder; pressure-equalizing means formed in said cylinder adjacent said neck; a

barrel member that is vertically reciprocable relative to said body member and includes a plunger tube telescopically slidably disposed within said neck; a hollow second piston formed on the end of said plunger tube disposed within said cylinder so as to define a first pumping chamber; one-way valve means formed in said body for controlling the entry of iluid into said lirst pumping chamber; a second cylinder formed on said barrel member and slidably encompassing said second piston so as to deiine a second pumping chamber; aperture means formed between said second pumping chamber and said plunger tube to establish communication between said tube and said second pumping chamber; and, second one-way valve means formed in said barrel member for controlling the How of fluid out of said second pumping chamber.

2. A well pump, comprising: a body member having a cylinder and an upstanding tubular neck extending upwardly from said cylinder; a hollow upper piston formed on the upper end of said neck; pressure-equalizing means formed in said cylinder for connecting its upper portion to the well bore fluid; a barrel member that is vertically reciprocable relative to said body member and includes a plunger tube telescopically slidably disposed within said neck; a hollow lower piston formed at the lower end of said plunger tube and disposed within said cylinder so as to dene a lower pumping chamber; standing valve means formed in said body below said lower pumping chamber and communicating therewith; a second cylinder formed on said barrel member and slidably encompassing said upper piston so as to deiine an upper pumping chamber thereabove; aperture means formed in said plunger tube to establish communication between said tube and said upper pumping chamber; and, travelling valve means formed in said barrel member above said aperture means.

3. A well pump, comprising: a stationary body member having a cylinder and an upstanding tubular neck extending upwardly from the upper end of said cylinder; a hollow upper piston formed on the upper end of said neck; pressure-equalizing ports formed in the upper portion of said cylinder for connecting its upper interior to the Well bore iuid; a barrel member that is vertically reciprocally movable relative to said body member and that includes a vertical plunger tube telescopically slidably disposed within said neck; a hollow lower piston formed at the lower end of said plunger tube and vertically slidably disposed with said body cylinder so as to deiine a lower pumping chamber below said lower piston; standing valve means formed in said body below said lower pumping chamber for controlling the entry of liuid thereinto; an upper cylinder formed on said barrel member and slidably encompassing said upper piston so as to deiine an upper pumping chamber thereabove, the lower end of said upper pumping chamber thereabove, the lower end of said upper cylinder being open to well bore pressure; aperture means formed in the upper portion of said plunger tube to establish communication between said tube and the interior of said upper pumping chamber; and, travelling valve means formed in said barrel member above said aperture means for controlling the upward flow of fluid out of said pumping chambers,

4. A well pump, comprising: a stationary body member having a cylinder and an upstanding tubular neck extending upwardly from the upper end `of said cylinder; a hollow upper piston formed on the upper end of said neck; pressure-equalizing ports formed in the upper portion of said cylinder for connecting its upper interior to the well bore fluid; a barrel member that is vertically reciprocally movable relative to said body member and that includes a vertical plunger tube telescopically slidably disposed within said neck; a hollow lower piston formed at the lower end of said plunger tube and vertically slidably disposed within said body cylinder so as to define a lower pumping chamber below said lower piston; standing valve means formed in said body below said lower pumping chamber for controlling the entry of uid thereunto; an upper cylinder formed on said barrel member and slidably encompassing said upper piston so as to deline an upper pumping chamber thereabove, the lower end of said upper cylinder being open to well bore pressure and terminating above the upper end of the cylinder formed on said body; aperture means formed in the upper portion of said plunger tube to establish i communication between said tube and the interior of said upper pumping chamber; and, travelling valve means formed in said barrel member above said aperture means for controlling the upward liow of fluid out of said pumping chambers.

5. A well pump for use with well tubing and a string of sucker rods that is vertically reciprocable within said well tubing, comprising: a stationary body member formed with a vertical cylinder and a coaxial upstanding tubular neck which extends upwardly from the upper end of said cylinder; a hollow upper piston formed on the upper end of said neck; pressure-equalizing ports formed in the upper portion of said cylinder for connecting its upper interior to the well bore fluid; a barrel member having its upper end securable to the lowermost of said sucker rods whereby it may be reciprocated vertically relative to said stationary body member, said barrel member including a coaxial depending plunger tube telescopically slidably disposed within said neck; a hollow lower piston formed at the lower end of said plunger tube and vertically slidably disposed within said body cylinder so as to define a lower pumping chamber below said lower piston; standing valve means formed in said body below said lower pumping .chamber for controlling the entry of uid thereinto; an upper cylinder coaxially formed on said barrel member and slidably encompassing said upper piston so as to define an upper pumping chamber thereabove, the lower end of said upper piston being open and terminating above the upper end of the cylinder formed on said body member; aperture means formed in the upper portion of said plunger tube to establish communication between said tube and the interior of said upper pumping chamber; travelling valve means formed in said barrel member above said aperture means for controlling the upward flow of fluid out of said pumping chambers; and anchor means interposed between said stationary body member and said well tubing.

References Cited in the iile of this patent UNITED STATES PATENTS 1,629,792 Hunter May 24, 1927 1,943,034 Myers Ian. 9, 1934 2,054,322 Hoferer Sept. 15, 1936 2,298,567 Kelly Oct. 13, 1942 Patent No, 2,817,298 December 24, 1957 Peter Sa Bloudoff Column 5, liney 9, lines 53 and 54, Jnher'eabove,"

for' "second piston" read first mentioned piston= strikev out "the lower end of said upper' pumping chamber Signed and sealed this 15th day of April 1958.,

(SEAL) Attest:

KARL H., AXLINE ROBERT C. WATSON Attesting Officer issioner of Patents