US3247798A - Method and means for operating a pumping oil well - Google Patents

Description

Filed May 16, 1962 P 1966 c. o. GLASGOW ETAL METHOD AND MEANS FOR OPERATING A PUMPING OIL WELL 4 Sheets-Sheet l a Q E k g 0 Q m Q kg no 1 0 m fl I" 0, Q

Q Q) v N 7 o L w i Q n INVENTORS.

CLARENCE 0. GLASGOW CHARLES A PURSER April 26, 1966 c. o. GLASGOW ETAL 3,247,798

' METHOD AND MEANS FOR OPERATING A PUMPING OIL WELL Filed May 16, 1962 4 Sheets-Sheet 2 INVENTORS. CLA RENCE O. GLASGOW CHA RLES A. PURSE M KAM ATTORNEY April 1966 c. o. GLASGOW ETAL 3,247,798

METHOD AND MEANS FOR OPERATING A PUMPING OIL WELL Filed May 16, 1962 4 Sheets-Sheet 5 GAS INLET GAS OUTLET I INVENTORS. CLARENCE O GLASGOW CHARLES A. PUHSER A T TORNE Y A ril 26, 1966 c. o. GLASGOW ETAL 3,

METHOD AND MEANS FOR OPERATING A PUMPING OIL WELL Filed May 16, 1962 4 Sheets-Sheet 4 w in E 2 w & 5 RS 5 m WWW 0! u E m a 3 W IE o: m m am n3 z W 98 O l .N \w\ \w: 5/ .7 S J m5 5 W 5 M M NS k m8 f m: o k:

A T TORNE Y United States Patent 3,247,798 METHOD AND MEANS FOR OPERATING A PUMPING OIL WELL Clarence 0. Glasgow, Tulsa, Okla, and Charles A. lurser, Clay City, 11]., assignors to National Tank Company, Tulsa, Okla., a corporation of Nevada Filed May 16, 1962, Ser. No. 195,098 Claims. (Cl. 103*6) The present invention relates to control of the operation of the pumping engine of an oil well. More specifically, the invention relates to a system which supplies fuel vapor from the casing of a pumped oil well without waste and which shuts down the pumping of the oil well automatically when the well is pumped off.

There are many oil wells having a low gas to oil ratio. Where the gas pressure is not high enough to lift the well liquids to the surface, the well must be pumped. In general, an electric motor, or a gas engine, is used to move mechanical linkage connecting the engine to a pump mechanism down the well bore. The engine-driven pump can use hydrocarbon vapors from the well bore as fuel. The problem exists, however, in withdrawing fuel vapors from the well casing without wasting the fuel when its pressure is more than that required for the fuel system of the engine and to avoid pulling thecasing pressure down below a predetermined value.

When starting up a pumped well engine, a source of fuel is needed until the continuous supply of vapor from the casing can be brought to the engine. A reservoir of such fuel Vapor is required as a starting charge of fuel gas for running the engine until sufficient vapors can be brought from the casing to run the engine continuously.

. Finally, there is the problem of shutting down the engine at the proper time. In general, it is desired to shut down the engine after the well has been pumped off in order to avoid burning up the seals of the stuffing box which are mounted around the polish rod and to conserve fuel.

A primary objective of the invention is to pump hydrocarbon vapors from a casing only so long as necessary.

to supply the casing vapors as a fuel to the engine.

Another object of the invention is to provide a reservoir of fuel vapor when it is desired to start a pump engine and to have the supply of the reservoir automatically replenished from the supply system.

Another object of the invention is to stop the pump engine a desired time after the well has been pumped off.

The present invention contemplates a vapor pump connected to the casing of a well and actuated by the engine of the pumping well. The vapor pump is arranged to provide fuel vapors for the engine but to shut down as long as the fuel vapor it supplies to the engine is kept within a predetermined range of pressure. Further, the vapor pump is disconnected from the supply of vapor in the casing when casing pressure is lowered to a predetermined range.

The invention further contemplates a reservoir for fuel vapor attached to the conduit between the vapor pump and the engine to receive and store the vapor at the maximum output pressure developed by the vapor pump. The reservoir will maintain its supply of fuel vapor at its maximum pressure until connected to the pump engine to start the pump engine and run the engine at the beginning of the pumping period.

Other objects, advantages and features of this invention will become apparent to one skilled in the art upon consideration of the written specification, appended claims and attached drawings, wherein;

FIG. 1 is a perspective view of a complete system in which the present invention is embodied;

FIG. 2 is a partially sectioned end elevation of apparatus responding to the flow of liquids pumped from GENERAL PLAN Referring to FIG. 1, we show a complete system in which our invention is embodied. A well head is generally designated 10 and a gas engine 11 is mechanically linked to a downhole pump in the well to reciprocate the pump and lift well fluids to the surface.

The well has a casing 12 with a casing head 13 mounted I on its top. The tubing string 14 extends out of the casing, through the casing head 13 and has a tubing hea 15 mounted on its top.

The downhole pump is mounted within the tubing and has sucker rods extending up the tubing string to connect with engine 11. The top of the tubing head 15 must provide for mechanical access tov the sucker rod string. Therefore, a polish rod 16 is extended through packing in the top of tubing head 15 to provide mechanical connection between the downhole pump and engine 11. The remainder of the mechanical linkage be tween engine 11 and polish rod 16 is conventional, including a walking beam 17 pivoted from a frame at 18. One of the principal features of our invention is the fact that the power pivoting walking beam 17 about 18, to reciprocate the downhole pump can be utilized to actuate the structure of our invention and provide fuel for engine 11 from casing 12.

The general plan also includes provision for a fuel supply which can be used to start up engine 11 after it is shut down. Specifically, a reservoir tank 20 is connected to the conduit taking fuel gas from the casing 12. Tank 20 is connected to the fuel supply in such manner that it receives a charge of the fuel at the highest pressure developed by our invention. After engine 11 is shut down, tank 20 can be connected to engine 11 at any time by hand and supply enough fuel gas to run engine 11 until fuel gas is drawn from casing 12 to run engine 11 continuously.

The plan also includes shutting down engine 11 when the well is pumped off. The downhole pump lifts the Well fluids to the surface through tubing 14. When the fluids reach tubing head '15, they are discharged through conduit 21. Other processing equipment may be required near the well head, but this equipment is not shown in order to keep the illustration of the invention simple and more readily understandable. Therefore, conduit 21 is shown simply conveying well fluids directly to tanks 22 and 23.

In general, it is desired to run engine 11 only so long as there is fluid in tubing 14 to lift to tanks 22 and 23. It would seem elementary to sense the flow of fluids in conduit 21 and shut down engine 11 when their flow is dropped to some predetermined minimum value. However, the flow of fluids is not a simple action.

Gas in the fluids of a well can make the liquid flow quite erratic. pand as the surface is approached and push a liquid piston of oil and water out of the tubing. Then a period of pumping will follow when no liquids are produced into conduit 21. If the flow of fluids in conduit 21 were used directly to shut down engine 11, the engine would be shut down while there were liquids yet to be pumped from tubing 14. Obviously a time delay is needed between the Pockets of gas in tubing 14 can suddenly ex-' device responsive to flow in conduit 21 and the means by which engine 11 is shut down.

The simplest means to shut down engine 11 is to ground out its magneto. One set of simple contacts is needed to control the ignition system of the engine. The flow detector and time delay mechanism can control these contacts. Flow detector 24 is shown in conduit 21 and FIGS. 2 and 3 show how the ignition system of engine llll is controlled to shut down engine 11 when the flow of well fluids indicates the well has truly pumped off.

The three aspects of the general plan of the disclosure will be developed separately and coordinated to demonstrate the various combinations of methods of pumping an oil well and apparatus with which to enact the methods.

VAPOR PUMP General function Our invention provides a pump with which hydrocarbon vapors are withdrawn from casing i2 as needed to supply engine 11 as fuel. Every oil well has its individual characteristics. The oil-gas ratio is different with each well. The characteristics of the gas vapor and the liquids are different. Nevertheless, there is a certain class of pumping wells which have enough hydrocarbons in vapor form within the casing to run the engine if utilized through our invention.

We generally propose to pump vapor from casing 12 under carefully controlled conditions. If vapor is readily available in suflicient quantity, our invention still exerts careful control over withdrawal so the vapor will not be wasted. The casing 12 can then be regarded as a storage vessel from which fuel vapor is withdrawn as needed. It is quite possible that sufficient vapor would be available to run engine 11 and other engines of pumping wells not shown. For the sake of simplicity, we will show our pump withdrawing vapor from casing 12 as fuel for engine 11, maintaining a volume of the fuel for this purpose between the well head and engine 11 and supplying startup reservoir tank 20 for later use.

Our vapor pump is shown at 25, mounted firmly to the frame of the pumping unit, or fixed in relation to it.

Actuating linkage Pump 25 is mechanically connected to the linkage between engine 11 and the downhole pump in order to be actuated by the reciprocating linkage. There are many and varied arrangements of linkage possible between pump 25 and walking beam 17. This connection is important. It is necessary that the motion of the walking beam be geared to the stroke required for pump 25. Further, the linkage must be adjustable and repairable by the relatively unskilled pumper on the lease. Also, it must be rugged and dependable under the peculiar dirty conditions found in the oil fields. However, the linkage which actuates our pump is, from the standpoint of invention, a relatively minor element of the combination.

We have shown a flexible line 26 anchored at 27 to walking beam 17. Line 26 is then passed over a pulley 28 and down to attach to the actuated shaft or pump 25. As walking beam 17 rocks about pivot 18, anchor point 27 is carried through an are about pivot 18. Pulley 28 is mounted far enough from the straight line between pivot 18 and anchor point 27 to impart the reciprocation stroke length desired to the portion of line 26 extending from pulley 26 down to pump 25. Slack is taken up in line 26 by spring 29 to keep the flexible connection from slipping about and jerking the actuating stem of pump 25. Other linkage between the engine 11 and our vapor pump 25 is satisfactory and at least another embodiment of this feature will be shown infra.

Vapor connection Pump 25 has its vapor intake 39 connected to outlet 31 of casing head 13 with conduit 32. Through conduit 32, hydrocarbon vapor is withdrawn from casing 12 and discharged from pump outlet 33 into conduit 34.

The maximum pressure at which the fuel vapor is placed in conduit 34 is expected to be normally established by an adjustment within vapor pump 25. The fuel gas, at the output pressure of pump 25, is discharged into a separator vessel 35. From the volume of separator 35, fuel gas is supplied to the input regulating system of engine 11.

There may be liquids withdrawn with the hydrocarbon vayor from casing 12. Also, condensation may take place from the vapor withdrawn. Separator 35, in addition to providing a supply volume of vapor for engine 11, also provides an opportunity for the liquids carried along in conduit 34 to settle out of the vapor. These liquids fall to the bottom of separator 35. A level detector in the form of a float 36 is positioned by the liquid level within separator 35 and controls the discharge of the liquids through conduit 37. These liquids, which are expected to be made up largely of water, are discharged through conduit 37 to a waste pit. In addition to this continuous withdrawal of liquids from the bottom of separator vessel 35, liquids are periodically withdrawn through a manually controlled drain conduit 38 which is shown extending from the bottom of separator vessel 35. Periodic cleanup of the bottom of separator 35 is desirable because a lot of dirt and paraffin is likely to collect at this point in the system.

The fuel vapor, denuded of liquids and dirt, is then drawn from separator vessel 35 through conduit 39. The pressure is reduced to the level compatible with the engine 11, and the vapor is burned as fuel. Therefore, conduits 32, 34 and 39 tie the casing 12 to the engine 11 as a source of fuel for engine it. As long as engine 11 actuates the downhole pump, vapor pump 25 will draw fuel from the casing 12 as a reservoir and supply engine 11. Engine 11 will run as long as there are well fluids to be delivered through conduit 21. The detection of fluids flowing through conduit 21, and the control of the engine ignition by the detected flow, completes the cycle of the general operation. The conditions from well to well vary greatly, but the overall plan is simple as thus far disclosed.

Vapor pressure and capacity The vapor connection between the casing 12 and the engine 11 has many features. The function of the equipment in the vapor connection must be formulated to fully appreciate this embodiment of our invention. The fuel vapor available from casing 12 may exceed the demand of engine 11. The vapor may not he suificient to run engine 11 for the full pumping period. The pressure level of casing 12 may have to be kept within certain limits. These, and other conditions set the functional requirements of the vapor connection and the units included in the connection.

Formation pressure It would appear that reduction of pressure in casing 12 would increase flow of fluid into the well from the formation. This simple function of vapor pump 25 is expected in certain cases. A pumping well could be saved from abandonment by having its production increased by this one function of vapor pump 25.

However, regulation of Government may recognize that pulling a vacuum on one well will rob neighboring wells of production. The lower limit of pressure which can be maintained on the producing formation to which casing 12 extends may be limited by law.

Relief valve 40 is placed in conduit 32. Valve 40 can be set to automatically vent conduit 32 to atmosphere when the casing pressure is reduced to a predetermined value. This air, brought into the vapor connection to engine 11 will shut down engine 11, if no alternate source of fuel is provided. This is one limitation on the use of fuel vapor from casing 12 which the operator may be willing to accept. On the other hand, it is possible to provide an alternate source of fuel for engine ll during the period of low pressure on the producing formation.

To absolutely and positively prevent air from being sucked into casing 12, a check valve 41 is provided between relief valve 40 and easing head connection 31. The check valve 41 is oriented so that a pressure in conduit 32 higher than the pressure in casing 12 will not cause flow back into casing 12. Air is thereby. isolated.

from casing 12.

The pressure of vapor in casing 12 may 'be in excess of the output pressure established for pump 25. In such case, the amount of vapor available for fuel in casing 12 may support the function of other well pumps similar to 11. Although not specifically shown, a system in which fuel vapors of casing 12 can be used by pump engines other than 11 falls within the concepts embodied in the system we disclose. A conduit to such engine, or engines, could be teed from conduit 32, 34 or 39 and extended to where needed.

If the pressure of casing 12 exceeds what is considered as a safe limit for a specific vapor connection and included units, a relief valve could be provided to flare so much vapor as required for safety. In general, however, the casing 12, and the formation to which it connects, desirably functions as a storage reservoir for fuel gas for engine 11. If the system is sized and engineered correctly under the concepts of our disclosure, the vapor available within the casing 12 will be drawn off for the useful purpose of running engine 11, or some other service, without waste and with the benefits of maintaining a low pressure on the formation to help production flow into tubing 14.

Vapor pump junction Conduit 32 brings the fuel vapor from casing 12, or air through relief valve 40, to input connection 30 of vapor pump 25. Pump 25 is actuated by walking beam 17 to increase the volume of a chamber connected to conduit 32. The expanding volume of the pump chamber reduces the chamber pressure and causes the contents of conduit 32 to flow into the expanded volume of the pump chamber. A check valve at the input connection 30 positively prevents fluid flow from the pump chamber back into the conduit 32. The actuation of the pump continues; the volume chamber is reduced in size and the vapor drawn into the pump chamber is compressed. Once thevapor in the pump chamber exceeds the pressure of the contents of conduit 34, the flow of vapor is from the pump chamber and into conduit 34. The force exerted to collapse the volume of the pump chamber comes from a spring, weight or other mechanism within pump 25. In any event, the result is a delivery of vapor from casing 12 to conduit 34 at a pressure determined by the pump mechanism. The outlet connection 33 of the pump 25 has a check valve oriented to positively permit flow from the chamber out connection 33 but to prevent reversal of flow into the pump chamber.

Obviously, in considering the relation of pressures in the system, the vapor pressure of casing 12 could increase until their force exceeded that of the pump mechanism urging reduction of the pump volume. If this higher source pressure developed, the vapor would simply pass through conduit 32, check valve 41, the check valves of the pump 25 and into conduit 34. The vapor, as fuel, would pass through separator 35 and down conduit 39 to engine 11. If the pressure of the vapor from casing 12 became too great for the safety of the conduits, and units in the conduits, it could be flared or piped to other useful locations.

Once the fuel vapor passes through separator 35 and into conduit 39, it merely has to be regulated to the few ounces of pressure required for its use in engine 11. Pressure regulator 45 is provided in conduit 39, just ahead of engine 11. Regulator 45 takes the pounds of pressure normally supplied from pump 25 and reduces it to the order of 6-7 ounces of pressure normally supplied an engine.

START-UP RESERVOIR While considering conduit 39 as the source of fuel gas for engine 11, the problem of starting up the engine should be considered. The system for fuel supply disclosed basically depends upon either native pressure of the formation flowing fuel gas continuously or the pump 25 functioning to keep up the pressure. The availability of fuel at start-up depends upon the conditions under which the engine was shut down. It is quite likely that in many situations little or no pressure is available from separator 35.

We conceive of a reservoir of fuel gas always available to engine 11 to run the engine until vapor pump 25 has developed the supply system pressure to a level for continuous operation. Tank 29 embodies the concept of such stand-by reservoir.

We place a check valve 46 in conduit 39, oriented to pass gas to the engine. Tank 20 is connected by con 'duits 47 and 48 to conduit 39 and across valve 46. Check valve 49 is placed in conduit 47 to permit flow only into tank 20 from conduit 39. Manually controlled valve 50 illustrates the control over placing the fuel gas of tank 20 into conduit 39, at the entrance to regulator 45.

The operation of this system is almost self-explanatory from this clear illustration. .The, maximum pressure attained by vapor in conduit 39 will cause the vapor to flow from conduit 39 into tank 20, through check valve 49. Check valve 49 will prevent back-flow from tank 20 if and when the pressure in conduit 39 decreases below its maximum. Therefore, regardless of the pressure in conduit 39 at start-up, fuel vapor is available from tank 20 to run engine 11 when manual valve 50 is opened. Check valve 46 blocks the flow of vapor back down conduit 39.

ENGINE SHUT DOWN As indicated supra, the engine 11 should be shut down when it is no longer needed. In general, if the liquids in the tubing have been pumped out, and the inflow from the formation is less than the liquids being pumped, the engine should be shut down until enough liquids have collected in the tubing to justify another pumping period. Also, of course, shutting down the engine will save the fuel it would otherwise require.

. There are other reasons for shutting down the engine 11. Polish rod 16 extends out of the top of tubing casing 15 through a fluid seal, referred to asa packing. This packing material is held in position by a retaining structure referred to as a stuflin'g box. If polish rod 16 is reciprocated through the packing of the stuffing box after the liquids have been pumped from the tubing, the lubrieating function of the liquids will be lost and friction will eventually heat the packing and damage the polish rod while burning out the packing. A system could be devised to supply a lubricant continuously to the polish rod packing, independently of the produced liquids. However, there are many pumped wells which simply have a stufiing box with packing lubricated from the oil produced from the well; once these liquids are evacuated, the pump should be shut down.

There are two general ways to shut a gas engine down. First, the fuel supply could be cut off. If there is insufiicient fuel vapor available from casing 12, the engine will be starved for fuel when the pressure falls below the 4 or 6 ounces required. Also, air drawn into the conduits 32, 34- and 39 through valve 40 is the equivalent of positively terminating the fuel supply to engine 11.

The second way of shutting down the engine 11 is to ground the ignition. The details of the arrangement of a conventional ignition system need not be disclosed to advance the invention of our application. When the magneto is grounded, ign-irtion sparks are not delivered to the cylinders of engine 11. The arrangement needed to accomplish this interruption of the engine 11 ignition is disclosed sufficiently by representing an electrical connection 55. Connection 55 extends from engine 11 to flow detector 24. When the flow of liquids stops in conduit 21, connection 55 is connected to the ground. The engine 11 ignition system is interrupted and the engine it shuts down. There are many possible variations of structures which will detect iiow in conduit 21. FIGS. 2 and 3 disclose the details of our preferred embodiment.

FLOW DETECTOR AND IGNITION CONTROL A flow detector could be placed in conduit 21 at any location desired. The detector is shown in FIG. 1 at a location where it is convenient to extend line 55 from engine 11. At this location, detector 24 is sectioned to show a primary element in the form of a pendulum which oscillates under the forces of liquid flow and gravity in conduit 21.

Ball 56 is suspended by link 57 from pivot point 58 in the housing of detector 24. Well fluid entering the housing from conduit 21 strikes the ball 56 and link 57 and pivots them to the position indicated in dashed line. When the flow falls to a low value, the ball returns to the position shown in FIG. 1 by gravity. If the flow of fluids is in surges, the pendulum pivots to and fro, the oscillation being a positive manifestation of the delivery of fluids through conduit 21.

The delivery of fluids by the reciprocation of a downhole pump is ideally suited to be sensed by this system. The pulsing delivery swings the primary element pendulum. When the well is pumped off, no fluids are delivered to tanks 22 and 23 through conduit 21, and pendulum 56, 57 stops swinging. A predetermined time after pendulum 56, 57 stops swinging, the flow detector connects line 55 to the ground, and the ignition of engine 11 is thereby interrupted.

FIG. 2 shows the sectioned housing of detector 24 from one end. Ball 56, link 57 and pivot point 58 are indicated. From pivot point 58, shaft 59 is shown extending through the back wall of the housing and bearing 69. The housing has an extension 24A into wi ich shaft 59 extends. Various partitions are shown in housing extension 24A, acting as supports and bearings for shafts connected to shaft 59.

Bearing 60 is mounted on the back wall of the housing and within housing extension 24A. Shaft 59, extending through bearing 66 from pivot point 58, carries part of the structure of ratchet 61 at its end. Ratchet 61 is not shown in detail because there are several forms of ratchet mechanisms which will be suitable to transfer the rotary power of shaft 59 in one direction. Regardless of the specific form which may be selected for this ratchet 61, the mechanism functions to rotate shaft 62 in one direction only as shaft 59 oscillates.

The unidirectional rotation of shaft 62 turns shaft 63 through a friction clutch 64. .There can be many refinements introduced to this system. However, we indicate the general principle involved by disclosing shaft 63 rotated in one direction, through clutch 64, against the force of spring 65. Spring 65 is attached by one end to housing extension 24A and by the other end to shaft 63. Spring 65 has sufiicient power, when wound, to rotate shaft 63 against the force of friction clutch 64. At the same time, shaft 63 is rotated through clutch 64 with a speed sufficient to keep spring 65 wound and maintain contact arm 66 on shaft 63 against stop 67.

As long as shaft 63 is turned against the force of spring 65 through clutch 64-, contact arm 66 is kept against stop 67. Once shaft 63 stops rotating from shafts 59 and 62, due to the fact that fluid is no longer being pumped from the well, the force of spring 66 starts rotating shaft 63 and attached contact arm 66. Contact arm 66 is then rotated by spring 65 against magneto wire 55. An escapement mechanism can be included in the structure to provide for more accurate movement of contact arm 66 at a predetermined rate from stop 67 to magneto wire 55 under the force of spring 65.

This specific arrangement of shaft 63, spring 65 and contact arm 66 can be varied within the scope of our disclosure. The essential cooperation sought is a winding of spring 65 to maintain contact arm 66 away from magneto wire 55. When shaft 63 ceases to rotate, or is no longer urged to rotate through clutch 64, spring 65 takes over the control of contact arm 63 and rotates shaft 63 and contact arm 66 into engagement with magneto wire 55. When magneto wire 55 is grounded by contact arm 66, engine 11 is thereby stopped a predetermined length of time after fluid is no longer pumped from the well.

Although we have shown a fairly specific mechanism with which to stop engine If, we are by no means limited to this preferred embodiment of the concept. The basic idea is to establish a response to the flow of pumped liquids from the well. Whatever mechanism is used for that detection, the magneto in engine 11 is grounded a desirable length of time after the well has been pumped oif.

VAPOR PUMP STRUCTURE Vapor pump 25 was previously discussed as an element of the overall combination providing a source of fuel for engine 11. The operation of the internal structure was referred to in the general sense. We disclosed how inlet conduit 32 was connected to check valve 30 and how outlet conduit 34 was connected to check valve 33. Through these check valves, both conduits are connected to the chamber within pump 25 which is alternately increased and decreased in volume by actuation through flexible link 26. FIG. 4 discloses additional details of internal structure of the vapor pump which will fully clarify its operation under the concepts of our invention.

Diaphragm housing 70 is a distinctive characteristic of our vapor pump. Between the two halves of housing 70 is clamped a diaphragm 71. Reciprocation of diaphragm 71 within housing 70 will cause the chambers formed between housing 70 walls and diaphragm 71 to alternately increase in volume and decrease in volume. The upper chamber 72 is vented to atmosphere with port 73. The lower chamber 74 is connected to conduits 33 and 34 through their check valves. Diaphragm 71 is raised and lowered by flexible link 26 to alternately increase and decrease the volume of chamber 74. As explained heretofore, the enlargement of chamber 74 will suck vapor through conduit 32 while decreasing the volume of chamber 74 will expel this selfsame vapor into conduit 32.

Diaphragm plates 75 and 76 may be clamped on each side of diaphragm 71 to give chamber 74 a well defined dimension. More specifically, shaft 77 is extended up through the center of plates 75 and 76, bringing this combination of plates and diaphragm against an upwardly facing shoulder 78. An upper shaft 79 is then journaled over the end of shaft 77 extending above plate 75 to capture the plates and diaphragm between shoulder 78 and the lower end of shaft 79. The upper end of shaft 79 is attached to flexible link 26.

Upper shaft 79 and lower shaft 77 extend through the Walls of housing 71 through suitable seals. Diaphragm housing 7i is mounted on a cylinder 86 and the lower shaft 77 extends coaxially downward into this supporting cylinder 80. A spring 81 contacts the lower end of shaft "/7 and the underside of casing 70. Adjusting screw on the lower end of shaft 77 establishes the compression of spring 81 and therefore the force with which spring 81 carries diaphragm 71 downward to decrease the volume of chamber 74. There are many other structural details of vapor pump 25, but it is felt that these features designated are sufficient to illustrate the invention.

As shaft 79 is pulled upward by flexible link 26, spring 81 is compressed. The volume of chamber 74 enlarges to bring in vapor from conduit 32. When link 26 is 9 released, or carried downwardly, spring 81 exerts its force to collapse the volume of chamber 74 and force vapor into outlet conduit 34.

When the pressure of the vapor in conduit 32 develops a force on the underside of diaphragm 71 equal to, or greater than, spring 81, diaphragm 71 will remain in its up position. Flexible link 26 acts only in the direction to pull diaphragm 71 upward. If diaphragm 71 is already in its up position, flexible link 26 will cause no movement of the internal mechanism of pump 25 on its downstroke and no movement on the upstroke until the pressure within chamber 74 permits spring 81 to lower diaphragm 71.

GENERAL SYSTEM OF FIG. 5.

Referring to FIG. 5, we show a complete system which is similar to that previously disclosed in FIG. 1. A well head is generally designated 110 and a gas engine 111 is mechanically linked to a downhole pump in the well to reciprocate the pump and lift well fluids to the surface.

The downhole pump is mounted within the well tubing and has sucker rods extending up the tubing string to connect with engine 111. A polish rod 116 is extended through packing in the top of the tubing head for mechanical linkage to the sucker rod string from engine 111. The remainder of the mechanical linkage between engine 111 and polish rod 116 is conventional, including walking beam 117 pivoted from a frame at 118. The power that pivots walking beam 117 about 118 to reciprocate the downhole pump, can be utilized to actuate our vapor pump and provide fuel for engine 111 from the well.

. As explained in connection with FIG. 1, the general plan includes a provision for a fuel supply which can be used to start up engine 111 after it is shut down. A reservoir tank 120 is connected to the conduit taking fuel gas from the casing of the well. Tank 120 is connected to the fuel supply in such manner that it receives a charge of the fuel at the highest pressure developedby our invention. After engine 111 is shut down, tank 120 can be connected to engine 111 at any time by hand and supply enough fuel gas to run engine 111 until fuel gas is drawn from the well to run engine 111 continuously.

Also, as in FIG. 1, the plan includes shutting down engine 111 when the well is pumped off. The downhole pump lifts the well fluids to the surface through tubing. When the fluids reach the tubing head they are discharged through conduit 121. Conduit 121 is shown conveying Well fluids directly to tanks 122 and 123.

In general, it is desired to run engine 111 only so long as there is fluid in the tubing of the well to lift to tanks i122 and 123. FIGS. 1, 2 and 3 illustrate structure for sensing the flow of fluids from the well and shutting down the pump engine when their flow drops to some predetermined minimum value. FIG. 5 illustrates another form of structure in which the inventive concepts of our application are embodied.

It is simple to shut down engine 111 by grounding out its magneto. One set of simple contacts is needed to control the ignition system of the engine. The flow detector and time delay mechanism can control these contacts. A specific form of flow detector 124 is shown in conduit 121 for controlling the ignition system of engine 111 to shut down engine 111 when the flow of I well fluids indicate the well has truly pumped oflF.

Actuating linkage 19 i 5, a somewhat different linkage is disclosed which will, however, actuate vapor pump satisfactorily.

A simple link 126 is pivoted by one end from walking beam 117 a finite distance from pivot point 118. A second link 127 is pivoted by one end from the supporting frame and by the other end from link 126. A third link 128 is pivoted at an intermediate point on link 127, between its end pivot points, extending down to connect to pump 125. Obviously, from the geometry of the linkage as disclosed, a vertical stroke is provided for link 128 proportional to the vertical stroke of link 126. The attachment between the upper end of link 128 and link 127 can be established along the length of link 127 to adjust the vertical stroke length for link 1228.

In the lower end of link 128 a slot 129 is provided in which the end of the reciprocated shaft of vapor pump 125 is retained.

In general, link 12% is shown at the upper end of its stroke range. The lower end of slot 129 has raised the pump mechanism to its upper travel limit. When link 1223 is carried downwardly in its vertical stroke, the spring within pump 125 will carry its mechanism downward. If the vapor pressure within pump 125 has been developed high enough to prevent the pump spring from carrying its mechanism downward, slot 129-provides relative movement between link 128 and the pump mechanism so that link 128 functions to stroke the pump mechanism only when the vapor pressure exerts a force less than the force exerted by the spring of the pump.

Flow detector and ignition control The flow detector of FIG. 5 has the same general function as the detector disclosed in FIG. 1. The inherent nature of the principles used in this disclosure of FIG. 5 require that the detector mechanism be placed at an elevation above the tanks 122 and 123. From this position, fluids flowing from the detector can gravity into the storage tanks. Otherwise, detector 124 can be positioned anywhere in conduit 121.

Detector 124 does not operate on the force of surging flow of pumped well fluids. In general, the fluids are received within the housing of detector 124, the housing 130 functioning essentially as a tank, or container, for a finite volume of the fluids. In general, it is expected that nor mal production of pumped liquids will maintain the finite volume of the liquids; when production is stopped for a period of time calculated to indicate the well has actually pumped off, the finite volume of liquids in housing 130 flow into tanks 122 and 123 and engine 111 has its ignition interrupted. The drawing clearly illustrates the apparatus in which this concept is embodied.

A stand pipe 131 is mounted vertically inside container 139. The well production from conduit 121 flows into the top of the housing 131). A separation of gasand liquids takes place inside housing 131]. Gas may flow out conduit 132 to a recovery system or flare. Conduit 132 may not be needed it stand pipe 131 is large enough to give gas pressure equalization with tanks 122 and 123.

In any event, the liquids rise to the top of stand pipe 131 and overflow into the storage tanks. This finite volume of liquids 133 is a part of the potential. timing devices calculated to stop engine 111 *when the well has pumped off. When the volume of liquids 133 are released from housing 131) at a controlled rate, their level sinks below the top of stand pipe 131 until float 134 lowers. The powering of float 134 grounds wire 155 to the housing 131), interrupting the ignition of engine 111.

The timing device including the volume of liquids 133 also includes an aperture 135 in the lower end of stand pipe 131. The size of aperture 135 is fixed so the liquids pumped into housing 130 will not all drain therethrough.

The capacity of aperture 135 is fixed at a value which which will overflow stand pipe 231i, aperture 135 establishes the time it will take the level of these liquids to lower far enough to lower float 13-4, and short wire 155. The Well may pump liquids erratically. Gas may build up in the tubing and cause surging discharge of liquids. Every well is different in its production characteristics. However, the volume of liquids 133 can be fixed, and aperture 135 can be sized, to give a time delay between production interruption and the stopping of engine 111 which will prevent temporary production interruption from prematurely shutting down the pump of the well.

Dirt, parafiln and other foreign matter will accumulate at aperture 135 in stand pipe 131. An accumulation of this nature will plug aperture 135 or at least reduce it in effective size. Therefore, to maintain the calibration of the system we have provided a plunger which can be periodically used to clean out aperture 135. A lever 136 is actuated by a chain 137 to move plunger 138 against the force of spring 13%, and into aperture 135.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the method and apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcornbinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The present invention having been described, what is claimed is:

l. A system for operating a pumping oil Well, including,

an engine,

a downhole pump for raising liquids to the surface,

a linkage between the engine and pump,

a vapor pump actuated by the linkage and having the input to the pump connected to the vapor space of the well casing,

a volume chamber connected to the output of the vapor a connection from the volume chamber to the engine fuel intake,

and' means responsive to the pressure of the volume chamber tov position the vapor pump and linkage so the pump will not be actuated as long as the pressure of the volume chamber is within a predetermined range.

2. A system for operating a pumping oil well, in-

cluding,

an engine for the downhole pump,

a vapor pump actuated by the engine to withdraw hydrocarbon vapor from the casing,

a connection from the output of the vapor pump to the engine to supply the hydrocarbon vapor from the casing as fuel to the engine,

means for terminating actuation of the vapor pump by the engine when the pump output pressure to the engine reaches a first predetermined range,

and means for disconnecting the vapor pump from the casing when the casing pressure reaches a second predetermined range.

3. A system for operating a pumping oil well, in-

cluding,

an engine for the downhole pump,

a vapor pump with the input connected to the casing to withdraw hydrocarbon vapor from the casing,

a connection from the out-put of the vapor pump to the engine to supply the hydrocarbon vapor from the casing as fuel to the engine,

a valve in the connection between the vapor pump and the casing responsive to vapor pressure in the casing 1 .2 and arranged to effectively disconnect the casing from the vapor pump when the casing pressure is brought down to a first predetermined range of pressure and effectively connect the vapor pump to the atmosphere,

and means for terminating the actuation of the vapor pump by the engine when the output pressure to the engine reaches a second predetermined range.

4. A system for operating a pumping oil well, includmg,

an engine for the downhole pump,

a vapor pump with the input connected to the casing to withdraw hydrocarbon vapor from the casing,

a connection from the output of the vapor pump to the engine to supply the hydrocarbon vapor from the casing as fuel to the engine,

a gas-liquid separator of substantial volume in the connection between the vapor pump and the engine to remove liquid hydrocarbons from the system,

and means responsive to the pressure of the separator for terminating the actuation of the vapor pump by the engine when the output pressure to the engine reaches a predetermined range.

5. A system for operating a pumping oil well, includan engine for the downhole pump,

a vapor pump with the input connected to the casing to withdraw hydrocarbon vapor from the casing,

a connection from the output of the vapor pump to the engine to supply the hydrocarbon vapor from the casing as fuel to the engine,

a volume chamber connected to the connection between the vapor pump and the engine in an arrangement whereby the volume chamber receives and retains hydrocarbon vapors at the maximum pressure of the vapor pump output and delivers the vapors to the engine under manual control,

and means for terminating the actuation of the vapor pump by the engine when the output pressure to the engine reaches a predetermined range.

6. A system for operating a pumping oil well, including,

an engine for the downhole pump,

a vapor pump with the input connected to the casing to withdraw hydrocarbon vapor from the casing,

a connection from the output of the vapor pump to the engine to supply the hydrocarbon vapor from the casing as fuel to the engine,

means for terminating the actuation of the vapor pump by the engine when the output pressure to the engine reache a predetermined range,

means responsive to the flow of liquids from the downhole pump,

and means controlled by the flow responsive means to interrupt the ignition of the engine a predetermined time after the rate of How of liquids from the downhole pump is reduced to a predetermined minimum rate of flow.

7. In a fuel system for the engine of an oil Well pump which reciprocates a downhole pump positioned in the casing of the Well,

a diaphragm in a housing,

a stem mounted on the diaphragm at the center of the diaphragm,

means connected to the stem to urge the stem in one direction,

a mechanical connection between the stem and the reciprocated downhole pump to also reciprocate the stem and diaphragm in cooperation with the means urging the stem in one direction,

an inlet gas conduit between one side of the diaphragm in the housing and the well casing through which gas is withdrawn from the casing by the reciprocated diaphragm for as long as the pressure within the conduit is within a predetermined range,

and an outlet gas conduit between the same one side of the diaphragm in the housing and the engine through which the gas is delivered to the engine as fuel by the reciprocated diaphragm.

8. In a fuel system for the engine of an oil well pump which reciprocates a downhole pump positioned in the casing of the Well,

a mechanical linkage connecting the engine to the downhole pump to reciprocate the downhole pump,

a diaphragm mounted in a housing to provide at least one chamber on one side of the housing,

a stem extending through the housing and attached at the center of the diaphragm,

means attached to the stem to urge the stem in the direction which will reduce the volume of the chamber in the housing to a minimum,

a flexible mechanical connection between the stem and the reciprocating mechanical linkage so the stem -will be moved against the force urging the stem in the direction which will reduce the volume of the chamber until the diaphragm chamber pressure is within a predetermined range as the downhole pump is reciprocated,

a first gas conduit connected between the diaphragmhousing chamber and the well casing,

a first check valve in the first gas conduit arranged to permit flow of gas only from the well casing to the diaphragm-housing chamber for as long as the diaphragm chamber pressure is within the predetermined range,

a second gas conduit between the diaphragm-housing chamber and the engine,

and a second check valve in the second gas conduit arranged to permit flow of gas only from the diaphragm-housing chamber to the engine.

9. A fuel supply for the engine of an oil well pump,

including,

means responsive to the pressure of the second conduit to position the gas pump and linkage so the pump will not be actuated as long as the pressure of the second conduit is within a predetermined range,

a pressure regulator in the second conduit to maintain the pressure of the gas engine inlet at the order of 6 to 7 ounces of gauge pressure,

a source of auxiliary gas stored near the wellhead,

a third conduit connected from the source to the second conduit upstream of the first pressure regulator,

and a manually operated valve in the third conduit whereby the gas of the auxiliary gas can be supplied the engine for an initial period at start-up.

10. A system for operating a pumping oil well, includan engine for the downhole pump,

a vapor pump actuated by the engine to withdraw hydrocarbon vapor from the casing,

a connection from the output of the vapor pump to the engine to supply the hydrocarbon vapor from the casing as fuel to the engine,

and means for terminating actuation of the vapor pump by the engine when the pump output pressure to the engine reaches a predetermined range.

References Cited by the Examiner UNITED STATES PATENTS 245,101 8/1881 Thayer 103-46 531,537 12/1894 Klein 103-46 828,680 8/1906 Quick 103-46 1,172,994 2/1916 Hulf 103-27 1,183,129 5/1916 Small 230-162 1,812,088 6/1931 Dunn 123-120 1,953,808 4/1934 Kenneweg 123-136 2,064,750 12/1936 Hurst 103-37 2,223,112 11/1940 Lear -169 2,487,876 11/1949 Johnson 55-169 2,728,517 12/1955 Shumaker 230-46 2,765,742 10/1956 King 103-6 2,772,828 12/1956 Bush 230-46 2,798,662 7/1957 Evans 230-162 2,869,466 1/ 1959 Osterhout et a1 103-27 2,870,715 1/1959 Barrett 103-6 2,982,466 5/1961 Pier 230-14 3,001,519 9/1961 Dietrich et a1. 123-136 LAURENCE V. EFNER, Primary Examiner.

Claims (1)

1. A SYSTEM FOR OPERATING A PUMPING OIL WELL, INCLUDING, AN ENGINE, A DOWNHOLE PUMP FOR RAISING LIQUIDS TO THE SURFACE, A LINKAGE BETWEEN THE ENGINE AND PUMP, A VAPOR PUMP ACTUATED BY THE LINKAGE AND HAVING THE INPUT TO THE PUMP CONNECTED TO THE VAPOR SPACE OF THE WELL CASING, A VOLUME CHAMBER CONNECTED TO THE OUTPUT OF THE VAPOR PUMP, A CONNECTION FROM THE VOLUME CHAMBER TO THE ENGINE FUEL INTAKE, AND MEANS RESPONSIVE TO THE PRESSURE OF THE VOLUME CHAMBER TO POSITION THE VAPOR PUMP AND LINKAGE SO THE PUMP WILL NOT BE ACTUATED AS LONG AS THE PRESSURE OF THE VOLUME CHAMBER IS WITHIN A PREDETERMINED RANGE.

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