US2946387A - Oil and water separating pump for oil wells - Google Patents

Description

July 26, 1960 c. L. HOOKER, JR

OIL AND WATER SEPARATING PUMP FOR 011. WELLS Filed Nov. 7, 195'? m N T N e e E 5 o w z T 2 I O T 0 A H G L s m E v. m B M i C u o z T G 8 II] w. m I F 5;. a w/ 4 A. "M 8 nfl 9 5 5 1 ,n,. o I -uqm m4. 3 3-!- w w 3 V/uv/vv a 3 5 9 n [1: Z 1 /w Z 5 1 4 3 Al 4 2 4| 0 1/ 9 drill I I I 2 2. I z F 2,946,387 OIL AND WATER SEPARATING PUMP FOR OIL WELLS Charles L. Hooker, Jr., P.(). Box 1'5, Bradley, Fla. Filed Nov. 7, 1957, Ser. No. 694,960 15 Claims. (Cl. 166-105) The present invention relates to oil well pumps and more particularly to a pump for extracting oil from a mixture of oil and water;

It is an object of the invention to provide a pump of simple and rugged construction which may be installed in an oil well casing for the purpose of pumping oil from the casing while at the same time rejecting water which may be mixed with the oil.

It is a further object of the invention to provide a pump which will be practical and reliable in operation for the purposes set forth and which will have simple and easily manufactured components.

It is a further object of the invention to provide a pump having a cylinder which may be made in extreme lengths, possibly extending down into the oil well casing for a hundred or more feet and having a piston with astroke commensurate with the length of the cylinder.

It is a still further object of the invention to provide a pump which may be constructed in extreme lengths wherein a reciprocal piston may be actuated from top to bottom of the cylinder in a simple and practical manner with a minimtun of moving parts.

Briefly, my invention contemplates the use of a pump.

cylinder having a reciprocal piston therein wherein the piston is reciprocated by means of a shaft having a reversing thread, wherein the shaft is rotated as by an electric motor. The piston has a pawl arrangement secured thereto which coacts with the reversing thread of the shaft thereby causing the piston to reciprocate as the shaft rotates. Each time the pawl reaches an end of the reversing thread at the top or bottom of the rotary shaft the piston reverses direction. Thus, continual reciprocation of the piston is effected. Carried by the piston at a lower surface thereof is a tube having a hollow central bore communicating with small lateral ports in the tube sides. The disposition of the tube is such that as it reciprocates up and down the cylinder with the piston, the laterally ported surface remains disposed within approximately the lower one-third of the cylinder. .Thus,

.water mixed with the oil separates out by gravity and flows through the ported side of the tube and down through the central bore and outwardly of the pump through a discharge valve provided in a separate housing attached to the lower end of the pump cylinder. By providing a valve port through the piston the lighter component of the oil-water mixture, namely the oil, communicates through the piston to the upper surface thereof and upon movement upwardly of the piston is lifted toward the upper end of the cylinder and ultimately out of the cylinder through suitably provided port means.

A detailed description of my invention will now be given in conjunction with the appended drawing in which:

Fig. 1 is a longitudinal section through the pump shown installed in an oil well casing, and

Fig. 2 is a section through 2-2 of Fig. 1.

Referring now to the drawing, a well casing 1 is disclosed wherein is disposed a pump cylinder 2 supported in the well casing as by a flanged coupling 5 to which is connected a discharge. pipe 8 suitably fastened in any known manner to a top cover 12 of the casing. Thus, the cover 12 may be welded to both the discharge pipe and the casing or threadedly connected thereto. Reciprocally disposed within the cylinder is a piston 15 sealed as by ice piston rings 18 and having a valve passage 22 in which is disposed the spring-biased ball check valve 25, as shown, it being understood that the valve 25 opens in the upward direction when the piston 15 is forced downwardly.

Inasmuch as the separating action taking place within the pump cylinder depends on the different specific gravities of the oil and the water of a mixture drawn into the cylinder, it will, of course, be appreciated that the cylinder is mounted vertically or substantially vertically so as to have a lower end 30 and an upper end 33.

Rising upwardly in the cylinder is a tubular shaft 36 non-rotatively secured to piston 15 as by a threaded stud carried at the end of shaft 36, as shown, or other suitable means. The tubular shaft carries a pawl 39 having a protrusion accommodated in a reversing thread 42 of conventional shape cut into a rotary shaft 45 which shaft is coupled by a pin as shown to a nipple 48 splined as shown to a power shaft SZ carried at the upper end of the discharge pipe in suitable bearings, and having a pulley keyed thereto. Thus, rotation of shaft 52 effects rotation of shaft 45 and by virtue of the pawl 39 secured to the tubular shaft 36 repetitive reciprocation of piston 15 is effected, the piston 15 being restrained against rotary movement in a manner to be hereinafter set forth.

Secured as by a threaded stud to the under face of the piston 15 and extending downwardly into the cylinder is a square shaft 58 which terminates in a square ported tube 62 having a central bore 65 and a series of small laterally disposed ports such as 68. The shaft 58 reciprocates in a square bore 71 in an end closure member 74 which may be threaded to the end of the cylinder as shown. The closure member 74 is provided with a coupling extension 81 which threadedly carries an outlet discharge means 84 at the bottom of which is secured a ball check valve 87 biased upwardly as by a spring so as to open to permit egress of fluid from the outlet discharge pipe 84 when suitable pressure occurs therein.

A spring-biased ball check valve 90 is carried by the closure member 74 and biasedv closed in a downward direction but being operative to open on an upward suction stroke of the piston 15.

The shaft 58 is polygonal in cross section exteriorly, for example, it may be square asshown. and co-acts with square bore 71 to prevent rotation of piston 15. Thus, the piston is restrained to pure reciprocation effected by rotation of the reversible thread member 45.

Thedisposition of the ports 68 is such that when the piston 15 is at the top of its stroke as shown the ports are disposed approximately within the lower third of the chamber formed by closure member 74.

In operation, assuming the piston is going in an upward direction effecting a suction stroke, the valve 90 opens while the valve 87 closes and a mixture of oil and water is drawn intothe lower portion 30 of the cylinder, valve 25 being closed at this time. During the rise time of the piston from its lowermost position to its uppermost position, the mixture being drawn into the cylinder below the piston begins to settle out, the heavier component, that is the water, forming a strata below the oil. Depending upon the rise time of the piston, a certain amount of the water will flow through ports 68 and bore 65 down into the outlet discharge pipe 84. Upon the return or downward stroke of the piston, the valve 25 is forced open and the lighter component of the mixture in the lower portion of the cylinder, namely the oil,

the lower face of the piston and the which has separated out at the top of the mixture, is

substantially oil-filled after a few strokes of the piston.

Upon each down stroke of the piston the mixture in the lower chamber, which is for the most part water, is forced through ports 68 and bore 65 into the outlet discharge pipe 84, cracking valve 87, whence the substantially watery mixture is forced back into the well casing. The valve 90 Will be understood to be closed at this time.

After the upper portion 33 of the cylinder becomes filled with oil, the oil is forced upwardly through ports 92. provided in the closure cap 5 and past a funnel-shaped guide means 93 which may be integral with the connecting nipple 48, and ultimately out of a discharge spout 97.

It will be noted that as the piston moves downwardly the ports 68 will ultimately be closed ofl by virtue of moving into the sleeve extension 81 of the end cap 74. This closing of the ports 68 cuts off egress of water or mixture from the lower portion of the cylinder to the discharge outlet 84, while at the same time builds up pressure for cracking the valve 25 so that the upper, or lighter oil strata of the fluid in the lower chamber may be forced into the upper portion 33 on each stroke.

It will, of course, be appreciated that the valve 25 is set to open at any predetermined pressure at a time subsequent to the uppermost port 68 being blocked by the sleeve 81, While the spring bias on the valve 87 is such that the valve is readily cracked upon an increase of pressure in the discharge pipe 84 as the piston moves downwardly. Valve 87 will, of course, remain open just so long as fluid is being forced into the discharge pipe 84.

From the foregoing description of the construction it will be apparent that the cylinder may be made extremely long. This is an important feature of the invention inasmuch as it requires a certain amount of time for the heavier water component of the mixture to settle to the bottom of the lower chamber for egress through ports 68. I have found that it takes some twenty or thirty seconds for effecting settling. In this time the piston 15 is continually moving on an up stroke and accordingly the greater the length of the cylinder the longer the up stroke in point of the time of the piston. Therefore, the speed of rotation of the reversible thread element 45 is correlated suitably to the length of stroke of the piston which is in turn dependent upon the length of the cylinder so as to provide a suitable rise time for the piston in order to eifectively permit the water to settle out of the mixture. By virtue of the very simple and rugged means for reciprocating the piston, namely the reversing thread component, a slow piston rise is readily effected, the pitch of the reversible threads having, of course, an eifect coupled with the speed of rotation on the rate of piston rise.

For extreme lengths of cylinder it is, of course, apparent that some reliance'on the pressure existing in the casing must be made in order to effect ingress of the mixture into the cylinder on each up stroke of the piston.

From the foregoing it will be apparent that the variable factors within control of the designer are the pitch of thread, speed of rotation of the threaded shaft, and length of cylinder. By suitable choice of speed and sizes the rate of rise of the piston to atford a proper degree of settling of the water at the lower portion of the cylinder may be readily arrived at for any pump required for use under practical operating conditions. 1

Having thus described my invention I am aware that various changes may be made without departing from the spirit of the invention and accordingly I do not seek to be limited to the precise illustration herein given except as set forth in the following claims.

I claim:

1. In a pump for separating a lighter from a heavier fluid of a mixture of said fluids, tubular means comprising a cylinder having an upper end and a lower end; an inlet valve communicating with the interior of the c'ylin der and an outlet valve at the lower end thereof; means comprising a reciprocating piston in said cylinder, a valved passage through said piston comprising a valve actuatable to open position in a downward direction of movement of said piston, and conduit means actuated in response to piston motion and in the same direction as said piston and etfecting communication between the lower end of said cylinder and said outlet valve for a predetermined portion of travel of said piston in said cylinder and disposed for directing a return flow of heavier fiuid to said outlet valve.

2. In a pump of the class described, a tubular means comprising a cylinder having an inlet valve communicating with the interior thereof, and having an outlet discharge means at one end thereof; means comprising a reciprocating piston in said cylinder, a conduit means 1 movable in response to movement of said piston and in the same direction and eifecting communication between said cylinder and said discharge means for a predetermined portion of travel of said piston in said cylinder.

3. In a pump for separating a lighter from a heavier fluid of a mixture of said fluids, a tubular means comprising a cylinder having an upper and a lower end; an inlet valve communicating with the interior of said cylinder and an outlet valve, said valves being disposed at the lower end of said tubular means; means comprising a reciprocating piston in said cylinder, a valved passage means through said piston comprising a valve actuatable to open position in a downward direction of movement of said piston, and ported tube conduit means actuated in response to piston motion and in the same direction and eifecting communication between the lower end of said cylinder and said outlet valve for a predetermined portion of travel of said piston in said cylinder and disposed for directing a return flow of heavier fluid to said outlet valve, wherein said cylinder is of such length as to effect a settling chamber for a heavier fluid to separate from a lighter fluid adjacent said lower end.

4. In a pump of the class described, a tubular means comprising a cylinder having an inlet valve communicating with the interior thereof and having a discharge means at one end; means comprising a reciprocating piston in said cylinder, conduit means actuated in response to piston motion and in the same direction and effecting communication between said cylinder and said discharge passage means for a predetermined portion of travel of said piston in said cylinder, including means for reciprocating said piston comprising a rotative shaft having a reversing thread; and means disposed at said end of said cylinder and co-acting with said conduit means for restraining rotation of said piston, said conduit means being secured non-rotatively to said piston and carried thereby.

5. In a pump of the class described, a tubular means comprising a cylinder having an inlet valve communicating with the interior thereof and having a discharge means at one end; means comprising a reciprocating piston in said cylinder, a conduit means reciprocal with said piston and actuated in response to piston motion and in the same direction and effecting communication between said cylinder and said discharge means for a predetermined portion of travel of said piston in said cylinder, said conduit means being carried by said piston, said cylinder having an end closure provided with a bore through which said conduit means moves toward said end of said cylinder, said discharge passage means comprising said movable conduit means and also comprising stationary housing means disposed exter1orly of said cylinder, in which housing means said movable conduit means reciprocates as said piston reciprocates, said housing means having an outlet valve for egress of return fluid therethrough.

6. In a pump of the class descr1bed, tubular means comprising a cylinder having an inlet valve communicating with the interior thereof, and having discharge passage means at one end; means comprising a reciprocating piston in said cylinder, a conduit means reciprocal with said piston and actuated in response to piston motion and in the same direction, and. effecting communication between said cylinder and said discharge passage means for a predetermined portion of travel of said piston in said cylinder, said conduit means being carried by said piston, said cylinder having an end closure provided with a bore through which said conduit means moves as said piston moves toward said end of said cylinder, said discharge passage means comprising a portion of said tubular means, and housing means disposed exteriorly of said cylinder, in which housing means said conduit means reciprocates as said piston reciprocates, said discharge passage means also comprising said housmg means.

7. In a pump of the class described, a tubular means comprising a cylinder having a discharge passage means at one end, means comprising a reciprocating piston in said cylinder having an inlet valve communicating with the interior thereof, conduit means comprising a ported tube reciprocated by said piston in response to piston motion and in the same direction, and eflecting a communication bet-ween said cylinder and said discharge means for a predetermined portion of travelot said piston in said cylinder, said ported tube being carried by said piston, said cylinder having an end closure provided with a bore through which said tube moves as said piston moves toward said end of said cylinder, said discharge passage means comprising said tube, and housing means disposed exteriorly of said cylinder, in which housing means said ported tube reciprocates as said piston reciprocates, said discharge passage means also comprising said housing means.

8. In a pump of the class described, a tubular means comprising a cylinder having an inlet valve communicating with the interior thereof, said cylinder having one end lower than the other end and a discharge passage means at the lower end, means comprising a reciprocating piston in said cylinder, conduit means reciprocal with said piston and actuated in response to piston motion and in the same direction and effecting communication between said lower end of said cylinder and said discharge means for a predetermined portion of travel of said piston in said cylinder, wherein said cylinder is of such length as to effect a settling chamber at the lower end thereof for a heavier fluid to separate from a lighter fluid, said ported tube being connected to said piston and carried thereby.

9. In a pump of the class described, a tubular means comprising a cylinderhaving an inlet valve communicating with the interior thereof and having an upper and a lower end and a discharge passage means at the lower end; means comprising a reciprocating piston in said cylinder, conduit means reciprocal with said piston and actuated in response to piston motion and in the same direction and effecting communication between said lower end of said cylinder and said discharge means for a predetermined portion of travel of said piston in said cylinder, wherein said cylinder is of such length as to effect a settling chamber at the lower end thereof for a heavier fluid to separate from a lighter fluid, said conduit means being secured to said piston and carried thereby, said cylinder having an end closure provided with a bore through which conduit means moves as said piston moves toward said lower end of said cylinder, said discharge means comprising said conduit means; and housing means disposed exteriorly of said cylinder, in which housing means said ported tube reciprocates as said piston reciprocates, including an outlet valve disposed in said housing means, said discharge means also comprising said housing means.

10. In a pump of the class described, tubular means comprising a cylinder having an inlet valve communicating with the interior thereof, and discharge passage means atone end thereof, means comprising a reciprocating piston in said cylinder, conduit means reciprocal with said piston and actuated in response to piston motion and in the same direction and efiecting communication between said cylinder and said discharge passage means for a predetermined portion of travel of said piston in said cylinder, said discharge passage means comprising said conduit means, and a valve carried by said piston and openable by pressure as said piston approaches said one end of said cylinder to permit fluid to pass through said piston as said piston approaches said one end of said cylinder.

11. In a pump of the class described, tubular means comprising a cylinder having an inlet valve communicating with the interior thereof, means comprising a reciprocating piston in said cylinder, conduit means actuated in response to piston motion and in the same direction, said cylinder having a closed end and a portion of said conduit means protruding through said closed end and reciprocally movable with respect thereto for establishing communication between the interior and the exterior of said cylinder for a predetermined portion of travel of said piston in said cylinder, means for reciprocating said piston toward said closed end whereby, as said piston approaches said closed end, fluid is forced through said conduit means out of said cylinder, said conduit means comprising a tubular element having a bore extending therein of predetermined length, said bore having a length shorter than the stroke of said piston and being open at the end of said tubular element exteriorly of said cylinder, and laterally disposed aperture means through said tubular element communicating said bore with the interior of said cylinder for said predetermined portion of travel of said piston toward said end of said cylinder.

12. In a .pump as set forth in claim 11, including an outlet discharge means exteriorly of said cylinder at said lower end thereof, said tubular element being reciprocal with said piston so that a portion of said tubular element moves to and fro Within said discharge means, said outlet discharge means comprising an outlet discharge valve.

13. In a pump for separating a lighter from a heavier fluid of a mixture of said fluids, tubular means comprising a cylinder having an upper end and a lower end; an inlet valve communicating with the interior of said cylinder and 'an outlet valve disposed at the lower end thereof; means comprising a reciprocating piston in said cylinder, a valve passage through said piston comprising a valve actuatable to open position in downward direction of movement of said piston, and flow conducting means actuated in response to piston motion and in the same direction thereof, and efiecting communication between the lower end of said cylinder and said outlet valve during a downward motion of said piston for directing return flow of a heavier fluid to said outlet valve for a predetermined length of travel of said piston in said cylinder.

14. In a pump as set forth in claim 13, said conducting means comprising a rod-like member having a hollowed portion for effecting said communication.

15. In a pump as set forth in claim 14, a discharge pipe disposed at the lower end of said cylinder, said outlet valve being disposed within said discharge pipe, said rod like member extending into said discharge pipe to eflect communication between said lower end of said cylinder and said outlet valve for said predetermined portion of travel of said piston.

References Cited in the file of this patent UNITED STATES PATENTS 1,104,962 Clark July 28, 1914 1,649,524 Hammond Nov. 15, 1927 2,022,859 Herbsman et a1. Dec. 3, 1935 2,214,064 Niles Sept. 10, 1940 2,296,164 Humphrey Sept. 15, 1942 2,523,091 Bruce Sept. 19, 1950 2,692,051 Webb Oct. 19, 1954 2,762,437 Egan et a1. Sept. 11, 1956 2,817,298 Bloudofl Dec. 24, 1957

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