US3103175A - Pumping apparatus - Google Patents

Description

H. c. HUMPHREY Sept. 10, 1963 PUMPING APPARATUS Filed July 24, 1961 7271115111111 rlfifivlzlzlzzzllrlrr 7,11,12,11,? 11/2719 5545555?!155,455$141556 I!!! I71:55:55,951!!! lllllll/III/lflll/IrII/l United States Patent 3,103,175 PUMPING APPARATUS Howard C. Humphrey, Liberty, Tex., assignor to Texaco Inc., New York, N.Y., a corporation of Delaware Filed July 24, 1961, Ser. No. 126,111

6 Claims. (Cl. 103-46) This invention relates generally to petroleum production and, inone specificc aspect, to a hydraulic oil well pumping system for use particularly in the pumping of deep producing wells. 1

Among the, advantagesof subsurface hydraulic pumping is that the use of sucker rods, with its attendant problems of rod breakage, wear, counterbalance and the like, is eliminated. Furthermore, with the provision of a central installation, hydraulic power is available for the pumping operation of a number of wells of varying depths and at varying distances from the source of hydraulic power.

The bottom hole pump for subsurface hydraulic pumping, referred to as a production unit, includes a hydraulic engine connected directly to a displacement pump. The engine consists of a reciprocating piston whose motion is controlled by a hydraulically actuated valve and which is driven and lubricated by power oil transmitted from the surface to the engine in the well.

The pump, at the lower end of the production unit, comprises a reciprocating piston connected directly to the engine piston. The pump intake is at the bottom end of .the. production unit and its discharge is drawn off by production tubing.

. Since the power fluid used to operate the production unit is crude oil drawn off from a surface tank battery, it is feasible to allow the power oil exhaust from the engine to be discharged into the pumped production fluid.

Although prior art subsurface, reciprocating piston type a more efilcient subsurface production unit.

It is another object of the invention to provide a simple pumping apparatus which requires minimum upkeep and care for proper pumping operation.

Still another object of the invention is to provide a simple pumping system for deep producing wells which is efficient yet requires a minimum of maintenance.

These and other objects, features and advantages of the invention will be apparent from the following description and claims when read in conjunctionwith the accompanying drawing wherein:

FIG. 1 is a diagrammatic partial showing of the installation for use with the present invention; and

FIG. 2 is an enlarged diagrammatic showing of the production unit.

The invention comprises reciprocating interconnected pump and power pistons, with pressurized fluid used for actuating the power piston for delivery of production fluid, the return of the power piston to original position comprising the intake pumping stroke for the production fluid.

I Referring to FIG. l of the drawing, the surface installation comprises a low pressure, power oil supply source or tank 1%, receiving a relatively small volume of oil released by the transmitter (not shown), a power oil line at 111 leading to pump 120, whence the power oil is delivered under pressure by line 13-!) leading from the pump to the high pressure power oil supply tank, indicated at 140, which not only holds the pressurized power oil but also a gas cushion indicated as 141. The power .oil leaves tank through pipe 142, passing through the intermitter at .150, which controls the direction of flow of the power oil and is shown diagrammatically simplified as a two way valve. After leaving the, intermitter, the power oil passes through pipe 10, (as shown herein) which is joined to power oil line tubing 11 at the casing head 12, closing the top of a producing well, with the production fluid, e.g. crude oil, being led off by production tubing discharging into a stock tank, as at 170.

A well hole 20, leading to the producing formation 21, is provided with a casing 22 held in position as by cement at 23. A string of production tubing 13 is shown suspended in the well, joined to power :oil line tubing 11 in a manner known in the art and held in position by the casing head 12 and spaced from the casing 22. The well production unit 14 is shown disposed at the lower end of the power oil line tubing string, which forms the housing for the power piston and pump plunger, and is joined to the production tubing at its lower end, and also is spaced from the casing. The production unit 14 is actuated by the power oil provided through the power oil line tubing 11.

Referring to FIG. 2, showing the production unit 14 in enlarged form, there is disclosed, diagrammatically, a bumper block 30, e.g. a spring-loaded shock absorber, seated in the power oil line tubing 11. This bumper block is perforated at 31 to allow flow of power oil and is used as a stop on the return stroke of the power piston 32, which is joined in spaced relationship to the pump plunger 33 by means of the piston rod 34. A packing gland at 35 surrounds piston rod 34 and prevents any production fluid from leaking past the pump plunger. The vent in tubing 11 at 35a is to equalize the pressure on the plunger 33, viz. to avoid building up pressure or a vacuum between the packing gland and the plunger.

Adjacent and shown parallel to the power oil line tubing 11 is the production fluid tubing 13 interconnected through duct means defining the delivery passage at 36 and the by-pass port at 37. The inlet valve for the production or well fluid is shown at 38 and the exhaust valve controlling its passage into the production tubing is shown at 3?. These valves are shown diagrammatically and in use would be caged. The use of a loading spring, indicated generally at 43, seated in the power oil line tubing 11 between the power piston 32 and the packing gland 35, for additional control of the return of the power piston and pump plunger, is optional.

The operation of the pumping process will now be described briefly. The power stroke of the production unit begins with the supply of power oil from the surface through the tubing 11 to the passage 31, forcing the free power piston 32 and so the pump plunger 33 downward to close the intake check valve 38 and to eject the production fluid from the production fluid chamber 15, defined in the tubing 11 between the pump plunger and the check valve at 38, through the exhaust check valve at 39 into the production tubing 13, up to the surface past the back pressure control means 161 in tubing 160 and then into the stock tank 170. Z

At the same time, production fluid retained within the power line tubing between the power piston 32 and the packing gland 35 is forced out through the passage 37, which is in open communication at all times between the power oil tubing 11 and the production tubing 13.

On the upstroke of the power piston 32 in the tubing 11 and so the intake stroke of the pumping cycle, the pressure of the production fluid upstream of the; bumper 30 is lowered by cut-off of the intermitter at'150, that is, the flow of pressurized power oil is shut off and the power oil which is in the power tubing 11 is permitted to flow back through the pipe into the low pressure, power oil supply tank 100 through the pipe line 180. This reversal of flow is possible because the hydrostatic head of the production fluid in the tubing 13, together with the loading spring 40, are suflicient to force the piston upward on its pumping stroke, thereby discharging the power oil into the low pressure supply tank at 100, the hydrostatic pressure in tubing 13 also closing the check valve at 39. The succeeding downstroke of the power piston is produced when the intermitter cuts oil the flow of the low pressure fluid from the power tubing 11 and permits pressurized power oil from the tank at 140 to pass through the pipe 10 into the power tubing 11.

The length of the power stroke is variable and is determined by the intermitter, which is regulated to produce the amount of production fluid desired, ie the allowable, or to obtain a stroke to produce the maximum amount of well fluid possible. In addition, the produced fluid is relatively gas-free, for with the intake 14 to the production unit extending below the surface of the fluid in the well bore, the released gas would pass up in the annulus between the tubings 11 and 13 and casing 22 and would be bled off through the conduit 24 with control valve 25 therefor. Also, two or more of these production units can be placed in series.

-Due to the proximity of the sources of supply, the hydraulic fluid used herein has been disclosed as power 01 Thus there has been shown and described an improved deep well production system which is simple to construct, economical to use, and has a minimum of Working parts to require maintenance.

The present application is a continuation-in-part of my co-pending application, Serial No. 783,245, filed December 29, 1958, now abandoned.

Other modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

l. A free piston pump for a producing well having a casing and with power fluid tubing and production tubing positioned in said producing well and spaced from said casing thereof comprising the combination of a pair of spaced imperforate pistons housed in said power fluid tubing, rod means interconnecting and spacing said pair' of imperforate pistons from each other, inlet means for production fluid leading to said power fluid tubing and located below one of said pair of pistons and including a check valve which opens when said pistons move on an intake stroke and closes when said pistons move on a discharge stroke, duct means establishing communication between said power fluid tubing and said production tubing, one of said duct means being in open communication at all times between said production tubing and said power fluid tubing leading to the chamber therein between said pistons'and another or said duct means being located adjacent said inlet means, and discharge control means comprising a second check valve which opens when said pistons move on a discharge stroke and closes when said pistons move on an intake stroke and being located adjacent said another of said duct means adjacent said inlet means.

2. In the pump as defined in claim 1, a packing gland surrounding said rod means interconnecting said imperforate pistons and being positioned in said power fluid tubing below said one of said duct means and sealing said power tubing against the flow of production fluid past said packing gland.

3. In the pump as defined in claim 2, said power fluid tubing having an opening in the wall thereof located below said packing gland surrounding said rod means and above the uppermost position of said one of said pair of pistons, said power fluid tubing and said production tubing being parallel to each other.

4. In a production unit for subsurface pumping for discharging production fluid into production tubing having a valve housed therein for checking reverse flow of said production fluid, the combination of an imperforate power piston and an imperforate pump plunger spaced from each other, a piston rod interconnecting said power piston and said pump plunger, a packing gland surrounding said piston rod, power fluid tubing housing said piston and said plunger and providing power fluid for linear movement of said power piston and so a corresponding movement of said pump plunger, an inlet valve for production fluid and with said pump plunger defining a chamber for production fluid having discharge means into said production tubing adjacent said valve housed therein, said production tubing having open communication with said power fluid tubing through duct means ending adjacent said packing gland and leading to the chamber in said production fluid tubing between said piston and said pump plunger whereby production fluid under hydrostatic pressure acts on said power piston on the pumping intake stroke. 1

5. In the production unit as defined in claim 4, resilient means spaced between said power piston and said packing gland in said power fluid tubing for additional control of the intake stroke of the pumping cycle of said production unit.

6. In combination with a subsurface pumping appara tus for discharging production fluid into production tubing having a check valve against reverse flow of said pro duction fluid and comprising a production unit of an imperforate power piston and an imperforate pump plunger spaced therefrom, a piston rod interconnecting said power piston and said pump plunger, a packing gland surrounding said rod and power fluid tubing housing said piston and said plunger and providing power fluid for linear movement of said power piston and so a corresponding movement of said plunger and a'check valve located in said power fluid tubing and defining with said pump plunger a chamber therewithin, said production tubing being joined to said chamber and said check valve in said production tubing being located adjacent said chamber, the improvement comprising a power fluid circuit joined to said power fluid tubing for providing power fluid thereto, and including sources of low pressure and high pressure power fluid and interconnecting pressurizing means and a valve means joining said power fluid circuit to said power fluid tubing for connecting said sources in turn with said power fluid tubing whereby high pressure power fluid is directed against said power piston for the discharge stroke of the pumping cycle and at the end of said discharge stroke said high pressure fluid acting against said power piston being released to the source of low pressure power fluid through said valve means, said production unit including resilient means spaced between said power piston and said packing gland around said rod in said power fluid tubing, said production tubing having open communication with the chamber between said piston and said plunger in said power fluid tubing adjacent said packing gland whereby production fluid under hydrostatic pressure acts on said power'piston on the intake stroke of the pumping cycle.

References Cited in the file of this patent UNITED STATES PATENTS 2,014,613 Ceverha Sept. 17, 1935 2,095,602 Huff Oct. 12, 1937 2,122,823 Overall July 5, 1938 2,185,727 Emmons Ian. 2, 1940 2,376,538 Hardey May 22, 1945

Claims (1)

1. A FREE PISTON PUMP FOR A PRODUCING WELL HAVING A CASING AND WITH POWER FLUID TUBING AND PRODUCTION TUBING POSITIONED IN SAID PRODUCING WELL AND SPACED FROM SAID CASING THEREOF COMPRISING THE COMBINATION OF A PAIR OF SPACED IMPERFORATE PISTONS HOUSED IN SAID POWER FLUID TUBING, ROD MEANS INTERCONNECTING AND SPACING SAID PAIR OF IMPERFORATE PISTONS FROM EACH OTHER, INLET MEANS FOR PRODUCTION FLUID LEADING TO SAID POWER FLUID TUBING AND LOCATED BELOW ONE OF SAID PAIR OF PISTONS AND INCLUDING A CHECK VALVE WHICH OPENS WHEN SAID PISTONS MOVE ON AN INTAKE STROKE AND CLOSES WHEN SAID PISTONS MOVE ON A DISCHARGE STROKE, DUCT MEANS ESTABLISHING COMMUNICATION BETWEEN SAID POWER FLUID TUBING AND SAID PRODUCTION TUBING, ONE OF SAID DUCT MEANS BEING IN OPEN COMMUNICATION AT ALL TIMES BETWEEN SAID PRODUCTION TUBING AND SAID POWER FLUID TUBING LEADING TO THE CHAMBER THEREIN BETWEEN SAID PISTONS AND ANOTHER OF SAID DUCT MEANS BEING LOCATED ADJACENT SAID INLET MEANS, AND DISCHARGE CONTROL MEANS COMPRISING A SECOND CHECK VALVE WHICH OPENS WHEN SAID PISTONS MOVE ON A DISCHARGE STROKE AND CLOSES WHEN SAID PISTONS MOVE ON AN INTAKE STROKE AND BEING LOCATED ADJACENT SAID ANOTHER OF SAID DUCT MEANS ADJACENT SAID INLET MEANS.

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