US1860137A - Method and apparatus for operating wells - Google Patents

Description

May 24, 1932. R. H. CARR 1,860,137

METHOD AND APPARATUS FOR OPERATING WELLS Filed April 17, 1931 3 Sheets-Sheet l amulet Carr May 24, 1932. R. H. cARR 1,860,137

METHOD AND APPARATUS FOR OPERATING WELLS Filed April 17, 1951 5 Sheets-Sheet 2 May 24, 1932. R. H. CARR METHOD AND APPARATUS FOR OPERATING WELLS Filed April 17, 1951 5 Shee'ts-Sheet 3 Patented May 24, 1932 I UNITED STATES.

PATENT oFFI-ca RICHARD H. CARR, OF CHICAGO, IIiLINOISTASSIGNOR TO, THE PURE OIL COMPANY, OF I v CHICAGO, ILLINOIS, A CORPORATION OF OHIO METHOD APPARATUS FOR OPERATING WELLS Application filed April 1'2,

This invention relates to an improved method and apparatus for effecting economically and eflic'iently the pumping of liquids from subterranean wells. In oil fields particularly, wells are often closely spaced or grouped and if a well'is capable of producing a reasonably large output of liquid, the common practice is to provide each of such producing wells with its own pumping equipment, rig and operating engine, such equipment having a capacity sufiiciently high to take care of the maximum liquid output of the well. In practice, this results in a very large amount of equipment in proportion to.

system, a heated fluid under pressure is utilized in effecting the operation of the pumping heads to provide for the pumping of liquids from the wells, the single compressor plant serving for a number of such wells and, further, meansare provided to admit'rcgulated quantities of the compressed fluid .to the pumping heads in a manner properly proportioned to the actual working requirements, as to liquid output, of each well of the system, all to the end of reducing well pumping costs and yet to provide-flexibility of control to increase or decrease, at will, the liquid output of a given well. V

Another object of the invention resides in a system of the character set forth which. includes essentially a closed cycle in which a gaseous working fluid iscirculated, the said fluid being first compressed by the compressor plant and delivered under suitable pressure to a distributing line and hence by valve control branches to the individual pum ing heads or cylinders of the various wellso the group,

1921. Serial No. 530,903.

provision being made for increasing the temmediately prior to the delivery of the latter, to each of the pumping heads, whereby to increase the volume of said fluid and render it more effective in operating the pumping heads. A

A further object of the nlvention resides 'perature of the gaseous working fluid, im-

in delivering the heated gaseous fluid under pressure to each of the pumping heads through the regulation of automatic valve control means, in order to effect the elevation of a piston slidably mounted in eachof said heads, the said piston being connected with the pollshed rod of the well pumping means so that its movement effects the actuation of the oil pump in the well'and the elevation of the oilor other liquid present in the well tubing. 1

It is a further object of the invention to provide through suitable valve means the controlled descent of the piston and associated parts, which is governed to a major degree by the back pressure carried on the return lines leading to the return side of the compressor plant, wherein PI'OVlSlOIl 1s made for delivering to the return side of the compressor the working fluid at a pressure of several atmospheres, thus reducing the power required to operate the compressor. Further, the setting or the opening and closing of the valve means also controls piston descent at the bottom of the pumping stroke, or use may be made of additional throttling means 8.5

for securing similar ends.

The invention further provides for the return of the gaseous fluid from the pumping description and the accompanying drawings,

wherein A Fig. 1 is a diagrammatic view showing the order or arrangement of the apparatus emheads under pressure to the inlet side of the compressor plant and its passage through astaken through the well pumping head, the

piston rod and the mechanlsm connected therewith for operating the valve means controlling the introduction and expulsion of a gaseous working fluid into and from the pumping head;

Fig. 4 is a horizontal sectional -view taken on the plane disclosed by the line 44 of Fig. 2;

Fig. 5 is a horizontal sectional view taken through the valve mechanism used in connection with the pumping head;

Fig. 6' is a vertical sectional view taken on the plane indicated by the line 66 of Fig. 5;

Fig. 7 is a-similar view on the line 77 of Fig. 5;

Fig. 8 is a detail side elevation disclosing the adjustable operating dogs which are operated by the piston rod of the pumping head for controlling the operation of the fluid inlet and outlet valves.

Referring more particularly to the drawings, the numeral 1 designates a gas engine, although any other suitable type of motion imparting means may be employed. This prime mover operates a compressor 2 through which air, or any other suitable aseous fluid,

and in certain instances liqulds', may be passed and placed under pressure. The discharge ports of the compressor are connected by means of the pipes 33 with a distributing line 4 by which the fluid, under pressure when discharged from the compressor 2, may be delivered to the individual wells comprising the pumping group. While two of such wells have been indicated in Fig. 1 nevertheless it will be understood that the invention is applicable to any suitable number, dependingupon such factors as the depth of the wells,

the fluid output thereof and the capacity of I the compressor plant 2. It will be understood thatwhile but a single compressor has been disclosed in the drawings, one or more of such compressors may be used, or one or more prime moversmay be used depending upon working requirements. While air may be used as the gaseous working or pumping fluid, yet it will be appreciated, as the description proceeds, that any other suitable gaseous fluid may be utilized and even liquids and the expression working fluid is therefore employed to embrace these'various gases or liquids. When a liquid is used as the pumping fluid, a pump will be used in lieu of the compressor. I I

Connected with the distributing line 4 are branch lines 5 which lead to the individual wells. Preferably, each branch line is provided wit-h a coil 6 which is arranged in a heater casing 7, whereby through the provision of this means, the working fluid may be subjected to an increase in temperature immediately prior to the delivery thereof to the well pumping heads or cylinders, which latter are designated in their entirety by the numeral 8. I

These well pumping heads each comprise a cylinder 9 substantially closed at both ends. In Fig. 2, this cylinder has been disclosed as being of the suspended type. However, it may be mounted on an elevated foundation or may be inverted with respect to its position as disclosed in Fig. 2. Usually, however, the cylinder is mounted immediately above the casing head of the well. Arranged in each cylinder is a sliding piston 10 which is connected by a piston rod 11 to the polished rod of a submerged well pumping means (not shown).

Secured to the-lower portion of each of the cylinders 9, when the latter are arranged as shown, is a valve casing 12 which is formed to include spaced inlet and outlet ports 13 and 14 for the working fluid, the inlet port being connected with that portion of the branch line 5 arranged on the dischar e side of the heater 7, while the outlet port 18 connected with the return line leading back to the compressor. Between the heater and the valve casing 12, each of the branch lines 5 is preferably covered or otherwise insulated to reduce heat loss on the part of the working fluid while passing from the heater to the pumping head. The valve casing is providsociated pumping means and, also, to govern the controlled descent of 'the piston and sus-' pended pumping means when the inlet valve is closed and the exhaust valve open. It will be understood at this juncture that this valve mechanism may be of any suitable type and while I have selected one form for clarity in illustration and description, nevertheless I reserve the right to employ any desired variation or the equivalent thereof.

As illustrated, the valves 15 and 16 comprise circular disk like bodies formed with tangentially extending ports 17, which ports are adapted to register with theports 13 and 14'and with communicating angularly disposed passages 18 which lead into theinterior of the associated pumping head or cylinder. The inlet valve 15 is keyed to an axially disposed shaft 19, which is mounted for rotation in suitable bearings formed in connection with the valve casing. The outlet valve 16 is mounted on a sleeve 20 which loosely surrounds the shaft 19. The outer ends of the shaft 19 and the sleeve 20 are provided with fixed operating cranks 21 and 22, the outer ends of these cranks being provided with spaced lugs 23.

Secured to the piston rod 11 for movement in unison therewith is a vertically extending angle bar 24 which is mounted for reciprocation in fixed guides carried in conjunction with a supporting frame work 25 of each pumping head. The angle bar 24 is thus permitted to reciprocate vertically in unison with the piston red, as shown more particularly in Figs. 3 and 4. The angle bar is formed with a series of perforations through which pass fastening elements which are employed in adjustably securing to the angle bar spaced sets of opposed dogs 26 and 27, the former operating the inlet valve and the latter the outlet valve by cooperation with the cranks 21 and 22 respectively. The dogs 26 and 27 are carried by the angle bar, and their operating extremities are spaced so that they will properly engage or register with the lugs 23 on the outer ends of the cranks 21 and 22. These dogs may be adjusted vertically of the angle bar so that any desired operation with respect to the opening and closing of the valves 15 and 16 can be secured, thus permitting said valves to be set or timed to secure any desired sequence of operation in the matter of fluid inlet and outlet into and from the pumping heads.

Thus the gaseous working fluid mav be introduced into the bottom of each of the cylinders 9, under approximately the conditions of pressure and temperature specified, although these conditions are subject to wide variation. The working fluid acts upon the under side of the piston 10 causing the latter to move upwardly in said cylinder and to operate the submerged well pump and raise the oil head in the tubing of the well casing. This movement is continued until the lower dog 26 on the angle bar engages with the crank 21 to close the inlet valve 15, substantially as shown in Fig. 6. The working fluid may then expand in the pumping cylinder until the up-stroke is completed and the working fluid reduced in pressure. At this point, the lower dog 27 engages with the crank extension 22 to open the exhaust valve, whereby to permit of the discharge of the gaseous working fluid from the pumping cylinder as the piston and the mechanism suspended therefrom descends. The exhaust valve is kept in an open condition until the upper dog 27 engages with the corresponding lug 23 on the crank 22, which rotates the exhaust valve to a closed position. This happens ordinarily just before the piston reaches the completion of its down-stroke in order that the air remaining in the cylinder may be used to cushion or check the descent of the piston and its associated means. Upon the completion of its descent movement, the intake valve is again tripped to provide for the inflow of the heated gaseous working fluid into the pumping cylinder, and the cycle of operation, as above given, is then repeated,

The working fluid discharged into the outlet lines 28 is then delivered to a return line 29 in which is disposed a suitable type of cooler 30. This cooler which may be of any desired type is employed for reducing temperature of the working fluid which is returned to the compressor tube under pressure, whereby to increase the volumetric efficiency of the compressor. One or more additional compressors 31 is utilized as a makeup unit for the purpose of initially charging the system when starting and for supplying air, or other working fluid, which is lost in the various pipe lines of the system due to leakage or other causes. The discharge from the compressor 31 is also passed through the cooling coils and is there mixed with the recycled air from the well heads. A pressure of approximately 110 pounds per square inch may be carried in the return lines, but this is subject to variation depending on such factors as the depth of the wells being pumped and, also, on the weight of the reciprocating parts of the pumping head, depending rods and the well pumping means.

A back pressure regulator 32 is arranged in a shunt line 33, connecting the distributing line 4 and the return line 29. This regulator will operate to prevent exhaust pressure on the distributing line 4 and is used principally for emergency purposes. Speed controllers or compressor unloaders or both (not shown) will be used on compressors or pumps to maintain specific pressure within desired limits of discharge pressure from compressor or compressors to and in the lines 4 and 5, and the same arrangement to control and maintain desired pressures will be used in connection with the compressors 31.

Arelief valve 34: is arranged in the return line 29 in advance of the cooler 30 and operates to relieve excessive air in the return system in the event the auxiliary compressor 31 should supply more than then required. Of course if a liquid is used as the working fluid, the compressors 2 and 31 will be eliminated and suitable pumps substituted. The temperature to which the working fluid is heated is subject to thermostatic regulation, whereby uniform temperature of the working fluid delivered to the well heads may be obtained.

In operation, air or other equivalent work ing fluid will be introduced through the valve casing into the well head cylinder 9. The piston within this cylinder will be.forced upwardly until the piston reaches a desired position on its upstroke, at which time the inlet valve mechanism is shifted automatically by the dogs 26 to cut off the incoming wor ing fluid and allow the fluid pressure within the cylinder 9 to complete the upward stroke. The discharge valve 16 is then opened by the automatic means specified and the work ing fluid is reduced to a pressure slightly less than that required to balance the static weight of the well, referring to the polished rod load. The reduced pressure within the cylinder 9 allows the piston to return on the down stroke, such down stroke being retarded at the end thereof to overcome the inertia of the sucker rods, etc., bringing the piston to its original position at the end of the down stroke. At this point, the valve mechanism is" again shifted, mechanically closing the discharge and opening the intake valve for another cycle. JIhere may be a lag between closing the discharge and opening the admission valves in order to utilize momentum of moving parts to compress air or gas in the cylinders 9 to pressures above the exhaust pressure before the admission valve is open. This is done to reduce clearance losses and application of operating power. While it has been stated that the working fluid enters the pumping cylinder at a pressure of approximately 300 pounds per square inch and a temperature of 550 F it is apparent that these figures are merely approximate and may vary in accordance with differing operation conditions.

The cylinder 9 is so designed that should anything fall, the piston will air cushion on either end of the stroke and will not wreck itself. The opening 32' shown in the upper portion of the cylinder is used as a vent to relieve air which may pass the piston rings and to relieve the upper part of the cylinder from compressing air to any substantial extent during the up-stroke or producing a vacuum in the upper end of the cylinder when the piston is lowered. Control valves 35 are provided in connection with each of the branch lines 5 and the return lines 29 to control well head operation. A governor may be installed in the air intake line to limit the speed of operation under any condition by being operated by the pumping head.

The lower portion of the piston rod is connected by means of an adjustable grip 35 with the polished rod 36, which extends through the well tubing shown at 37. The tubing extends through the usual casing head 38, and a pipe 39 is employed to conduct oil pumped from the Well through the tubing while a second pipe i0 is used to remove gas from the casing head. The derrick or frame work 25 may be of any suitable form and in this instance has its upper portion provided with a pair of spaced channel members 41 through which pass a pin 42, the latter being also passed through an eye 43 formed in the closure 44 for the upper end of the pump ng head. The lower portion of the pumping head is provided with a stufling box or gland 45 through which the piston rod operates.

It is Within the range of the invention to employ a working fluid which functions expansively in the well pumping head if desired. The well head cannot be considered as an engine for the-reason that it will not operate under no-load conditions. This therefore is in contrast with prior systems relating to closed cycle systems of operation wherein air or other fluid is transmitted by a pump or compressor to a distant engine. It has also been proposed to employ well heads operated by compressed air for the purpose of pumping wells and therefore no claim is addressed to this feature per se; however, as far as can be determined, the present invention is the first to provide a closedsystem of fluid circulation wherein provlsion is made for heating the working fluid prior to its delivery to the well head, the return of the fluid under pressure to the compressor or pump and the cooling of the fluid, in such cyclic operation prior to its return to the pump or compressor. It will be understood that the heating of the Workmg fluid prior to expansion in the pum ing cylinder prevents water vapors present rom freezing and clogging the operating mechanism. This is an important feature of the invention. These features provide collectively a system for operating oil wells which may be readily adapted to the horse power needs of a group of wells and in addition provides an economical, readily controlled and flexible system for effecting the operation of a group of such wells with but a minlmum of apparatus.

What is claimed is:

1. Apparatus for effecting the pumping of a plurality of oil wells from a common source of power, comprising: an engine driven compressor for placing an elastic working fluid under pumping pressures, a distributing line leading from the discharge side of said com-- pressor for conducting said fluid to a plurality of wells, a pumping head arranged at each of said wells for effecting the operation of associated pumping mechanism arranged as a in said wells, means for heating the working said we s, pumping mechanism connectedwith said headand arranged at each of said 1 wells, valve means automatically operative in accordance with the stroke of said pump ing head to admit said heated fluid at timed intervals-into each of said heads and to controlthe regulated discharge of the fluid un- 30 der reduced pressure from said heads, means for closing said valve means before the end of the pumping stroke to permit expansion of the working fluid, a return line leading from the fluid discharge side of saidlpump ing heads to the fluid inlet side of said compressor, said pumping heads operating to return the fluid to said compressor under a pres sureof several atmospheres, and a cooler Y in said return line for reducing the temperature of said returned fluid immediately prior to its delivery to the compressor.

3. Apparatus for effecting the pumping of a,plurality of wells from a common source of power, comprising :a compressor for placing an elastic working fluid underwell pumping pressures, a distributing line for conducting said fluid from the discharge side of said I compressor to a plurality of wells, means for increasing the temperature of said fluiddur- 0 ing its passage through said distributing hne' at each of said wells, a pumping head arranged at' each of said wells,'pumping mechanism connected with said head and arranged at each of said wells, valve means automatie cally operative in accordance with the stroke of said umping head to admit said heatedfluid at timed intervals into each of said heads and to control the regulated discharge of the fluid under reduced pressure from said heads,

0 means forclosing said valve means before the end of the pumping stroke to permit expansion'of the working fluid, a return line leading from th fluid discharge side of said pumping heads to the fluid inlet side of said compressor, said pumping heads operating to return the fluid to said compressor under n ,a pressure of several atmospheres, a cooler in 5 sad return line for reducing the temperature of saidreturned fluid immediately prior to its delivery to the compressor and. an auxiliary compressor, for maintaining -substan-,

tially constant'the quantity of. fluid in said circulating lines. 4

. 4. Apparatus for effecting the.pumping of 1 a plurahty of wells from a common source of power, comprising: a compressor for placing an elastic workin fluid under well pumping pressures, a distributing line for conducting said fluid from the discharge side of said compressor to a plurality of wells, means for increasing the temperature ofsaid fluid duringits passage through said distributing line at each of said wells, a pumping head arranged at each of said wells, pumping mechanism connected with said head and arranged at each of said wells, valve means automatically operative in accordance with the stroke of said pumping head to admit said heated fluid at timed intervals into each of said heads and to control the regulated discharge of the fluid under reduced pressure from said heads, means for closing said valve means before the end of the pumping stroke to permit. expansion of the working fluid, a return line leadingfrom the fluid discharge side of said pumping heads to the fluid inlet side of said compressor, said pumping heads operating to return the fluid to said compressor under a pressure of several atmospheres, a cooler in said return line for reducing the temperature of said returned fluid immediately prior to'its delivery to the compressor, an auxiliary compressor for maintaining substantially constant the quantity of fluid in said circulat- I ing lines, and means for maintaining said fluid under a redetermined pressure when passing throug said lines.

5. The method of operating a plurality of wells from a common source of power which comprises: operating a compressor to place an elastic fluid under'pumping pressures, de-' livering, said fluid to a pumpmg head arranged at eachwell whereby to effect the actuation of said heads and the pumping of liquids from the wells, heating the fluid immediately prior to its delivery to each of said pumping heads, expanding the fluid insaid pumping heads by shuttin off the supply thereof before the end of t e lifting stroke and utilizihg the available counterbalancing force of the wells to return said fluid under pressure to the suction side of said compressor. I 6. The method of operating a plurality of wells from a common source of power which comprises: operating the compressor to place an elastic fluid under pumping pressures, de-

liveringsaid' fluid to a pumping head arranged at'eaeh wellwhereby to effect the actuation of said heads and-the pumping-of liquids from the wells, heating the fluid immediately prior to its delivery to each of said pumping heads, expanding the fluid in said pumping heads by shutting off the supply thereof before the end of the lifting stroke, utilizing the available pressure to the suction side of said-v compressor, and cooling said flulds duringtheir I counterbalancing *force of the wellsto return said fluid under return passage from the pumping heads to said compressor.

7. Well pumping apparatus comprising: an engine driven compressor'for placing an elastic working fluid under pumping pressures, a supply line leading from the discharge side of said compressor, for conduct ing a fluid to an associated well, a pumping head arranged adjacent to said well for effecting the operation of associated pumping vmechanism arranged in the well, means for heating the working fluid during its passage throu h said supply line, valve means automatlcally operated in accordance with the stroke of said pumping head to admit said heated fluid at timed intervals into said head and to control the regulated discharge of the fluid under reduced pressure from said head, means for closing said valve means before the end of the pumping stroke to permit expansion of the working fluid in said head and a return conduit leading from the fluid discharge side of said pumping head to the fluid inlet side of the compressor.

8. Well pumping apparatus comprising: a compressor for placing an elastic working fluid under well pumping pressure, a supply line for conducting said fluid from the discharge side of said compressor to an associated well, means for increasing the temperature of said fluid during its passage through said supply conduit, a pumping head arranged adjacent to said well, pumping mechanism connected with said head and disposed in the well, valve means automatically operative in accordance with the stroke of said pumping head to admit said heated fluid at timed intervals into saidhead and to control the regulated discharge of the fluid under reduced pressure from the head, means for closing said vah'e means before the end of the pumping stroke to permit expansion of the working fluid in said head, a return ciated well, means for increasing the temperature of said fluid above its normal compressionv temperature during its passage through said supply conduit, a pump head arranged at said well, pumping mechanism connected with' said head and arranged in said well, valvev means automatically. operative by the stroke of said pumping head to admit said heated fluid at timed interval into said head and tocontrol the regulated discharge of the fluid under reduced pressure from said head, means for closing said valve means before the end of the pumping stroke to permit expansion of the working fluid in said head, a return conduit leading from the fluid discharge side of said pumping head to 'the fluid inlet side of said compressor', said pumping head operating to return the fluid to said compressor under a pressure of several atmospheres, a cooler in said return conduit for reducing the temperature of the returning fluid immediately prior to its re-delivery to the compressor, and means for maintaining substantially constant the quantity of the working fluid in said apparatus.

10. The method of pumping an oil well which consists in operating a compressor to place an' elastic fluid under pumping pres sures, delivering said fluid to a well pumping head whereby to efl'ect the actuation of said head and the pumping of liquid from the well, heating the elastic fluid immediatel prior to itsdelivering to said pumping hea expanding the fluid in said pum ing head by shutting oflf the supply thereof efore the end of the pumping stroke, and utilizing the available counterbalancing force of the well to return said fluid under pressure to the suction side of said compressor.

11. The method of pumping an oil well which comprises placing a working fluid under pumping pressure of the order of 300 pounds per square inch, heating the said fluid additionally, delivering said heated fluid to a well pumping head, causingsaid fluid to expand in said well pumpin head to per form work, and returning t e exhaust expanded fluid for recycling and for placing the same again under high pressure, the whole operation being carrled out in a .substantially closed s stem.

12. The .metho of pumpin an oil well which comprises placing a wor in fluid under pumping pressure of the or er of 300 pounds per square inch, heating the said working fluid while under pressure to a temperature of the order of 550 F., deliverin said heated fluid to a well pumping hea causingsaid fluid to expand in said well pum ing head to perform work, andreturning t e exhaust expanded fluid for recycling and for placing the same again under high pressureythe whole operation being carried out in a substantially closed system.

13. The method of pumpin an oil well which comprises placing a worfii der pumping pressure of the or er of 300 pounds per square inch, heating the said working fluid While-under pressureto a temperature of the order of 550? F., deliverin causing said fluid to expand -in said wel said heated fluid to a well pumping hea i 7 ing the exhaust expanded fluid, cooling such returned fluid substantially, and then placing such cooled return fluid under higher pressure for recycling and reheating, the entire operation being carried out in a substantially closed system.

14. The method of operating a plurality of wells from a common source of power which comprises placing an elastic fluid under a pressure of the order of 300 ounds per square inch, heating said pressed uid to a temperature of the order of 550 F., delivering said fluid under heat and pressure to a pumping

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