US2834294A

US2834294A - Deep well pump

Info

Publication number: US2834294A
Application number: US373955A
Authority: US
Inventors: Roger W Schoen
Original assignee: Alco Valve Co
Current assignee: Alco Valve Co
Priority date: 1953-08-13
Filing date: 1953-08-13
Publication date: 1958-05-13
Anticipated expiration: 1975-05-13

Description

May 13, 1958 Filed Aug. l5, 1955 R. W. SCHOEN DEEP WELL PUMP .3 Sheets-Sheet 1 May 13, 1958 R. W. SCHOEN DEEP WELL PUMP Filed Aug. 13, 1953 AN IK 5 Sheets-Sheet 2 R. W. SCHOEN DEEP WELL PUMP May 13, 195s 5 Sheets-Sheet 3 Filed Aug. l5, 1953 United States Patent DEEP WELL PUMP Roger W. Schoen, Mineral Wells, Tex., assignor to Alco Valve Company, University City, Mo., a corporation of Missouri Application August 13, 1953, Serial No. 373,955

Claims. (Cl. 103-46) The present invention relates to a deep well pump, and especially a pump of the hydraulic type actuated by a column of power oil conducted from the surface down to the bottom of the well, at which latter point the pump is located, and which pump includes p iston means and valving mechanisms that alternately port pressure from the power oil to and from one face of the power piston, so as to produce the reciprocating movement of the pump rod.

it is an object of the invention to improve the pumping mechanism so as to enable it to be contained within a smaller space than heretofore. Another object is to provide a pump of this kind which may be assembled and disassembled readily with a minimum number of tools of a minimum number of different characteristics.

A further object is to provide a reversing valve mechanism assembled7 with the pumping mechanism so that there is a mechanical reversing of the reversing valve mechanism at the end of each stroke of the piston. Also, it is an object to provide a pump mechanism that will not stop on -dead center, but rather is stall-proof.

Another object is to have a pump with relatively slow pump stroke and relatively fast return.

Other objects will appear from the fuller description to follow:-

ln the drawings:

Figures 1 through 5 represent successively lower parts of the pump motor and pump mechanism at the bottom of the well, shown in vertical diametrical section, there being some overlap in the several views so as to assure completeness of disclosure;

Figure 6 is a transverse section on the line 6 6 at the top of Figure 1 (in all the transverse sectional views the well tubing is omitted);

Figure 7 is a transverse section on the line 7-7 o Figure l;

Figure 8 is a transverse section on the line 8 8 of Figure 1;

Figure 9 is a view partly in section of the upper head .of the pump;

Figure 10 is a transverse section on the line 10-10 of Figure l;

Figure 11 is a somewhat diagrammatic view of the valving apparatus that appears in the lower half of Figure 1;

Figure 12 is a transverse section on the line 12--12 at the top of Figure 2;

Figure 13 is a transverse section on the line 13--13 of Figure 2;

Figure 14 is a bottom plan view of a spacer and sealer member at the lower end of the valve mechanism;

Figure 15 is a vertical section of the spacer and sealer taken on the line 15-15 of Figure 14;

Figure 16 is a transverse section through the pump taken on the line 16--16 at the upper part of Figure 2;

Figure 17 is a transverse section on the line 17-17 of Figure 2; and

Figure 18 is a transverse section on the line 18`18 of Figure 2.

2,834,294- Patented May 13, 1958 rice . The pump will be described as an oil pump, with the understanding that other fluids may be used. A well tubing T has been illustrated to show the disposition of the pump, the pump being inserted into the tubing and lowered down from the surface. The diameter of the tubing has been exaggerated for clarity in drawing. As is known in this type of pump, a power fluid tube 20 leads down from the surface to conduct power oil down, which power oil is put under pressure by an appropriate pressure generating mechanism at the surface, of which various types are known in the art; such as that illustrated in the application of John E. Dube and Roger W. Schoen, Serial No. 374,004 led Aug. 13, 1953.

The power oil tube 20 is connected into the head 21 of the pump motor mechanism. This head, in turn, is threaded into the upper end of an outer barrel `22 that extends downwardly so that it may enclose the valving apparatus and the power piston motor apparatus for the pump. The lower end of the outer barrel 22 connects through a threadedly removable closure 23 into a compound spacer device consisting of

spacer tubes

24 and 241 adjustably connected together. The spacer tube 241 finally is threaded onto the upper end of one of the standard sucker rod pumps, here generally indicated at 25. Since this pump forms no part of the invention, which is primarily concerned with the power mechanism to reciprocate the pumps, the pump itself will not be described. Sufce it to say that a sucker pump pull rod 26 extends upwardly from the top of the sucker rod pump 2S and constitutes the piston or plunger rod of the sucker rod pump, which is reciprocated up and down so as to cause the oil to be lifted. The upper part of the pump 25, as it appears in Figure 5, has openings 28 that constitute the oil outlets by which the pumped oil is delivered into the well tubing T upon the successive strokes of the pump, to be conducted to the surface. It is, of course, well known in this art that there is some sort of sealing means between the oil being pumped to the surface and the well oil at the bottom of the pump.

The pull rod 26 is threaded at its upper end into a coupling 30 that, in turn, is threaded into the lower end of a tubular connecting rod 31. The upper end of the connecting rod 31 connects into a piston assembly. Actually, the upper end of the connecting rod 31 ts through the lower end of a fitting 32, which has an enlarged opening extending downwardly from its upper end to provide a shoulder to receive and hold an internally threaded ring 33 removably threaded onto the threaded end of the connecting rod 31. It will keep the connecting rod from pulling downwardly out of the union 32. Above the ring 33 there is another coupling 34 externally threaded into the upper open end of the union .33, so that it keeps the connecting rod from moving out of the upper end of the iitting 32. In turn, the upper end of the member 34 receives the lower end of a pipe 35, which latter is threaded into the member 34.

The upper end of the pipe 35 is threaded into a ring nut 36 which clamps a piston device 37 onto the pipe 35 between the member 34 and the ring nut 36. The piston device may be of any suitable construction or assembly. Above the nut 36 a coupling 38 is threaded onto the upper end of the tube 3S. Its upper end, in turn, is threaded into a spring barrel element 39 for a purpose to appear.

The foregoing parts reciprocate with the sucker rod pump piston and provide an axial opening from the upper end of the cage 39 to the bottom end of the connecting rod 31.

The cage 39 is a part of an overtravel spring mechanism including a coil type overtravel spring 44) acting at its lower end against a retainer 41 of a cross-sectional shape illustrated in Figure 18. The upper end of the spring Taasafgeee 4) acts against a'shifter device 4H) which is provided with a shoulder 42, by means of whichit-is-retainedein the upper end of the overtravel spring cage 39.

Except in cases of overtravel, the shifter device 410 will reciprocate. with the connecting rodjarid'hhce Y'with the sucker pump. ,y

Reverting to the lower end of the-apparatus, as pr''viously indicated, there is an adjustable tubular extension of the outer barrel 22 formed by the fmer'nbers 24 yand 241, with which the sucker rod pump 25 is connected by the illustrated connections. JThis adjustable barrel, in tunpis threaded onto the connecting rod barrel 24. The adjustable barrel extension may regulate the relative positions between the sucker rod vpiston and cylinder (not shown), and the motor piston, to insure maximum sucker rod piston stroke.

The upper end of the spacer tube 241 has an extended internally lthreaded portion that receives the externally threaded lower end of the upper member 24. By this arrangement, the upper member 24 may be threaded yinto the lower vmember 241 a selected distance, after which the relative positions may be locked by a ring nut 43.

The upper end of the spacer tube 24 is threaded onto the retainer and closure 23. Thereis appropriate packing surrounding the connecting rod 31 inthe lower end of this retainer 23, and there is additional packing likewise arranged at the upper end. Chevron packing is preferred for the upper packing.

An upper packing retainer and sealer 44 lits into the upper end of the retainer 23 and also is stabilized and `sealed within the barrel 22. Suitable O-ring packing elements are provided at various points in the assembly as indicated.

The upper lend of the retainer 44 fits into the lower end'of an inner cylindrical barrel 46, and is causedto close the lower end thereof, by the retainer 23. The barrel 46 abuts on a tirm packing 47; and it extends upwardly to form-the cylinder for the piston 37. The inner barrel 46 likewise extends upwardly past the overtravel spring cage 39 and, at its upper end, seats around the lower reduced end of a centering spring cage 48, there being a suitable O-ring packing between the two, and the two also fitting firmly to transmit compressive-forces axially between the two, with suieient axial contact to resist lateral distortion of the assembly under compressive stress, which is likewise true of the fitting of the lower closure 44 and vthe inner barrel.

The centering spring cage 48'extends upwardly'and, at

its upper end, receives asealing and spacing member 50I t, that `appears in Figure 2k and separately in Figures 14 and 15. The centering spring cage 48 has a recess extending down from its upper end, which is shouldered at` its lower end so as to receive the spacer 50, and provide secure tit preventing lateral distortion under compression, The `spacer 50 has"afplurality of projections or feet 52 extending downwardly from its lower surface. These projections have a somewhat lesser diameter than the main body of the spacer, so thatthey extend into the centering spring cage 48 belowy the shoulder. rThese feet portions 52 are separated so as to permit uid'ow, as will appear. The spacer 50 also has a plurality of more or less semi-cylindrical cut-outs 53 that extend vertically between the several feet 52, all for purposes 4to appear.

The upper end of the spacer member 50- hasfsimilar feet-like projections 54, but these extend cut to the-diam eter of the spacer, and therebyV t into a valve cylinder 55 so that the latter extends down onto the spacer' 50-and yet so that there may be uid ow assured attheitop of the spacer 50 from the middley thereof to the surface of the cylinder 55. The cylinder S has a sealingt'- nto the spacer 50 to resist lateral distortion under compression on the assembly.

Thecylinder 55, which surrounds the valving 'inecha- A nismand is permanently and solidly'lit'ted 'ontota valve' y going parts.

body 56, extends upwardly and tits over and engages in abutting relation 4the upper head 21 of the pump device which is reduced in diameter within the outer barrel 22. As a matter of fact, reference to Figures l and 8 will show that there is a double reduction on the lower end of the head 21 so that the cylinder 55 will be spaced within the barrel 22.

Suitable O-rings as indicated may seal off the fore- The structure las described shows that the pump 25 is rigid with the spacer tube 241, and the latter is rigid with the lspacer tube 24, once those two parts are secured in proper adjusted relationship. In turn, the `spacer tube 24 is rigid with the packing retainer and closure 23 ywhich,'in turn, is rigid with the outer barrel 22, and the latteris rigid with the upper head 21.

Thus, if the foregoing parts are threaded tightly together, they will insure against change in the length of the pump structure.

'Inside the'foregoing barrel part, the packing retainer 23 and its upper packing head'44 are in ixed abutting relationship so that the member 44 can not move downwardly when the parts are secured together as aforesaid. Thenthe inner barrel 46 is in abutting relationship with the centering spring cage 48, and the latter is in abutting relationship with the spacer 56 which, in turn, abuts thevalve lcylinder 55,'which latter is in abutting relationship withthe upper valve head 21. We may comment thatthe valve body member 56 is also in abutting relationship ywith'the spacer Sil and with the upper pump head 21. Allof these parts have suflicient overlap to provide stability against lateral distortion when the upper headand lower closure 23 are tightened onto the outer barrel. 'Howev'er, the space between the outer and inner barrelsis small7 and even the distortion permitted by the=out`er`barrel would not seriously interfere with the pump.

lFrom the-foregoing, when the upper pump head 21 is threaded into position in the barrel 22, the inner parts mentioned are rigid and are held against extending lengthwise.

By the foregoing arrangement, the parts may be secured together, but 'also maybe readily disassembled with a minimum number of tools. v

The spacer 241 has lateral ports 60 at its lower end which open into the well casing. There are other ports 62 of'like'eharacter through the upper spacer tube 24, a'nd'at Vthe top of the latter there are still more ports 63. This assures against the development of a conned space which could ll with oil and resist pump action. There'canv be no trapped oil within the spacer Vtubes/'around the connecting rod 31.

The lower spacer tube 241 is provided'with opposed grooves 64 that are flats designed to permit application rolf a tool to this part for aid in dctaching it from the associated parts.

Reference to Figures 2 and 3 will show that the inner barrel 46' is'spaced inside the outer barrel 22 so that oil may p ass between the two. The lower end of the inner barrel 46 lhas ports 66 so that such oil may flow into an annular space 67 forming a lower pressure chamber, and mayfact'against a lower annular surface 68 on the member 32, which latter is assembled with the piston elcments-37so as to constitute with them a piston. The member 32 is slightly smaller than the inside of the inner barrel 46 and oil may iow around between these two parts until it reaches the piston member 37. This piston member-maybe 'an assembly of separate parts, if desired, but is shown as asingle member. vThe total effective .lowerpiston'area, therefore, consists of an annulus, with the outer diameter equal to the inner diameter of the inner barrel'46, and its innerdiameter equal to the outer diameter of the connecting rod 31.

The upperpressure or piston chamber 7i' is within the'nner barrel 46 above the piston. The upper surface 72- of the ovcrcenter'spr'ing' cage 39 'constitutesone part of the downstroke piston. area. As noted, the actuator 41 does not have a tight t with the lassociated elements, so that the oil may pass down within this part as well as within the overcenter spring cage 39. The retainer 41 has a plurality of more or less semi-cylindrical passages 74 (FiguresZ and 18) through it so that the oil may flow down into the vinterior of the hollow tube 35 that, in effect, constitutes the upper part of the connecting rod 31. Since these parts are secured together and have a common bore, this liquid may continue down until it reaches 'the head of the union member 30 which confines it at the bottom end of the hollow connecting rod 31. The total effective piston area for the top of the piston is the inner diameter of the inner cylinder 46.

It will be seen from the foregoing that the lower cylinder 67 is always in communication, with the space or passage 70 between the outer and inner barrels. This passage 70 continues upwardly inside the outer barrel 22, past the inner barrel 46, the cage 48, the fitting 50 and the valve shell 55, to the head 21, where it communicates directly with the power uid pipe. This latter is accomplished by connection of the latter into a well 80 in the head 21, from which two passages 81 (Figuresl, 6, 8 and 9) extend downwardly and laterally to the reduced portion of the head 21, above the valve shell 55, which is the upper closure for the passage 70.

Assuming for the moment the same hydraulic pressure to exist in the

cylinders

67 and 71, the piston would be driven downwardly because of the greater effective area on the upper side of the piston than on the lower side. This has been diagrammatically suggested by the arrows inthe two pressure cylinders, with the broken line extended across the upper cylinder 71 to illustrate the larger piston area for the downstroke. This is evident because the lower area is merely the annular space between the connecting rod 31 and the barrel 46, whereas the` top area producing the downstroke is the entire inner diameter of the barrel 46. The valving mechanism is designed to determine when the hydraulic pressure shall be admitted to both of these cylinders and when the pressure in the upper cylinder shall be exhausted.

In considering the valving mechanism, it is convenient to start at the top. The head 21 also includes so-called exhaust passages 85 that lead into the well casing so as to communicate with the oil being pumped or the production oil. These passages open through the bottom of the head 21, which head is provided with spaced feet 87 so that, although it is in contact with the upper surface of the valve body 56, it nevertheless'does not obstruct the ow of fluid from the passages 85 outwardly and downwardly. As appears particularly in Figures l and l0, the valve body 56 in its upper end has two peripheral grooves 89 extending down for a certain distance whence they communicate with lateral ports 90 leading to the axial bore 91 through the valve body from end to end. Owing to the various and separate feet 87 on the bottom of the head 21, the particular orientation about its axis of the valve body 56 with respect to the head 21 is immaterial. There may always be oil flow communication between the

passages

89 and 85.

The upper pressure cylinder 71 connects through a partition 93 in the centering spring cage 48. This partition 93 is shown in Figures 2 and 17. It has a plurality of holes 94 through it, so that it does not obstruct passage of Huid from the cylinder 71.

Above the partition is the centering spring chamber 95, the details of which are to be described. The centering spring chamber 975 is in continuous communication past the feet 52 on the sealing member 50, and thence vertically through the passages 53 and around the upper lugs 54, so as to be in constant communication with the lower end of the valve body 56.

t While the valve, as such, is not a part of this present invention, its adaptation into this assembly is a part hereof. It need be described only diagrammatically insofar Gf as the particular construction of its prtings is concerned.

Figure l shows that the pressure oil passage 70 outside the valve cylinder 55 communicates through the cylinder 55 and the valve body itself at three points. The lowest of these is the passages 1110'. The middle one is the passages 101. And the upper one is the passages 1112. By this arrangement, oil under pressure is always admitted into the central bore 91 of the valve body 56.

There are three valves in the axial bore 91 of the valve body 56. For this reason, there are two stop mem-- bers pinned into the valve body. There is a lower stop member that seals olf the bottom part of the bore from the intermediate part. This stop 105 is held in place by a pin 106. There is also a stop seal 1117 held in by a pin 108. The seal and stop 167 separates the intermediate valve chamber from the upper valve chamber. These stops separate three separate hydraulic valve systems.

Within the bottom valve chamber there is a mechanical valve 110. It has a depending valve stem and head that is latched into a Valve stem extension 111. To this end, the lower end of the valve has a reduced neck 112 and a head 113. The extension 111 has an enlarged head 114, having a recess for the head 113 in the reduced stem 112, with a lateral opening 115 to receive the stem 112, and a larger lateral opening 116 to receive the head113. By this means the extension 111 may readily be laterally passed onto the valve head, and yet held so that movement up or down of the extension 111 causes corresponding movement of the valve. The iit of the head 114 within the fitting 50 prevents lateral detaching movement of these parts when they are in operating positions.

The member 111 extends down through the partition 93 and is joined to another valve stern extension 120 by means of a threaded collar 121 engaged over the lower threaded end of the member 111 and the upper threaded end of the extension 120. In the positions illustrated, the collar 121 passes freely through a center opening in the partition 93. The collar forms abutments for purposes to appear.

The stem extends down freely through the actuator 41 in la manner sufficient to permit the passage of oil between the two. It has a length approximately equal to the stroke of the pump motor piston. At its lower end the member 120 is provided with a double nut 122- 123 tightly secured to the end of the extension stem 120 so as to provide an adjustable shoulder abutment element for a purpose to appear. Figure 18 shows that the retainer 41 tits reasonably closely with a sliding fit onto the stem extension 120 so that the nut 123 may act as an abutment against the bottom surface of the retainer 41. The lower end of the valve stem 120 and the locking

nuts

122 and 123 may move freely within the tube 35 of the piston, the

lunion 34 and the connecting rod 31.

The centering spring chamber 9S contains spring actuated centering mechanism for the mechanical valve 110. There are two anged, tubular, centering spring guides. The lower guide 125 rests on the upper end of the partition 93 without obstructing the vertical passages 94,

therethrough. The lower end of a coil spring 126 rests on the guide 125. The upper end of the coil spring 126 rests on the upper guide 127 which impinges upon the feet 52 on the bottom of the spacer, which feet are provided soI as to vassure flow through the passages 53 and around the guide 127. The spring 126 is a compression spring normally urging the two

guides

125 and 127 apart and into contact with the partition 93 and the spacer 50, respectively. The stem extension 111 passes through the guides and the spring. The head 114 and the upper end of the collar 121 are spaced Iapart a distance equal to the distance between the spacer 50 and the partition 93, so thatl the valve stem 110-111-120 is yieldably held in a middle position from which it may be dipslaced in either direction, and toward which it will be urged to return by the spring 126.

The valve 110 has four lands thereon. They are, reading from bottom to top, the

lands

130, 131, 132 and 133. Between the

lands

130 and 131 there is a valve passage 134. Between the

lands

131 and 132 there is a valve passage 135. Between the

lands

132 and 133 there is a valve passage 136.

Below die land 130 the valve is openV to the pressure within the upper cylinder 71. The space above the land 133 between it and the spacer 105 is similarly connected to the cylinder 71 by passages 13S. v

At this point, it is observed that the passage 138 is not illustrated completely, but is shown fragmentarily in a manner to indicate its presence. Actually, the passage extends to the surface-of the valve body member 56, and thence by a groove on the valve bodyk member that is enclosed by the cylinder 55. This groove extends parallel to the axis down to the space below the valve body. A dashed line indicates it. It will be seen that this dashed line also connects into a passage marked CYL, at the upper end of the valve body.

By the foregoing arrangement, the two opposite ends of the valve are always open to the pressure existing in the upper cylinder 71,

The mechanical valve `110 is designed to have three positions. It is illustrated in its intermediate or neutral position into which it is normally moved by the action of the centering spring 126. If the valve stem 120 is pushed upwardly, the collar 121 will impinge upon the lower guide 125, elevating the same against the spring 126 and causing the valve 110 to move to an upper position. In like fashion, if the valve stem 120 is pulled downwardly, it will, acting on the head of the extension 111, pull the upper guide 127 down, compressing the spring 126 and moving the valve 110 to a lower position.

In the middle position or neutral position illustrated in Figure 11, power oil is introduced by the passages 100 into the space 135, where it is trapped. Also, the oil at the pressure of the production oil in the interior of the well casing and carried down by the passages 85 is transmitted from above the valve body'56 through the passage 140 shown in Figure l0 and shown by a dashed line in Figure l1, to two

passages

141 and 142 leading respectively to the

valve spaces

134 and 136, in both of which it is then trapped.

If the mechanical valve 110 is moved upwardly until the two

guides

125 and 127 abut, it will connect the power oil passage 100 through the valve passage 135 to work passages 143 that lead, as indicated by a dotted line, up wardly to the lower pressure chamber below the'intermediate valve. At the same time, the upward movement of the mechanical valve 110 will cause the return line 141 to be connected through the valve space 134 to a passage 144 that is connected, as illustrated by the dotand dash line, into the upper pressure chamber of the intermediate valve. Hence, such shifting of the mechanical valve ports pressure or power oil to the bottom of the intermediate valve and connects the upper end thereof to exhaust. A consideration of the porting conditions when the valve 110 is lowered, until the two

guides

125 and 127 lare in contact, will demonstrate that the reverse porting of power oil onto the upper part of the intermediate valve and production oil pressure on the lower part will be produced. Also, whenever the mechanical valve 110 returns to neutral position, it hydraulically locks the pressures in the intermediate valve pressure chambers.

Power oil is continuously supplied through the ports 101 to the intermediate valve 150. The intermediate valve has four

lands

151, 152, 153 and 154. These afford, respectively, a lower valve passage 155, a middle valve passage 156, and an upper valve passage 157. They also provide for upper Iand lower valve operating chambersconnected respectively to the

lines

143 and 144 that are controlled by the mechanical valve soas to position` the intermediate valve, :as described. It is a two-'position valve, illustrated in its lower position. Its primary function is to position the upper main valve by regulating the connections into the chambers above and belowthis valve. And it functions to produce a relatively rapid action of the upper valve or main valve, avoiding its sticking in a mid-position.

In the lower position of the intermediate valve 150, illustrated, power oil enters the passages 101 and llows by the valve passage 156 to passages 160 that lead to the lower pressure chamber below the top valve. Meanwhile, the valve space 157 connects the passage 161 leading from the upper pressure chamber of the main valve to the return line by means of a passage 162. There is a similar passage 163 also connected into the return line 140 which, in the lower position of this intermediate valve, is just below the land 152.

When the intermediate valve is elevated to its upper position, the power oilto the passages 101 is cut olf from the passage 160 and is introduced to the passage 161 leading to the top of the main valve. Meanwhile, the bottom of the main valve is ported by the passage 160 to the lower valve space 155, whence it can connect through the passage 163 to the return line 140.

The main valve has a lower land 171, and an upper land 172. These are separated by a valving passage 173. In the illustrated upper position of the main valve, the power oil through the passages 102 is cut off by the lower land 171, and the upper cylinder 71 is connected through the passage 138 with the return line 89, which connects to the production oil space by way of the passage 140. This means that the upper part of the hydraulic motor piston is at production oil pressure. Upon reversal of tthe intermediate valve 150, the main valve 170 will be driven downwardly. This will cut off the passage 89 and connect the power oil passage 102 with the cylinder passage 138 through the valve space 173. This will put power oil pressure onto the upper cylinder 71.

The top of the valve'body passage is closed by a sealing plug 175 that alsoprovides an upper limit to the movement of the main valve.

Operation At the start, it is assumed that the power oil pipe 20 is connected to some suitable source of pressure on the surface such as a form of ipump that can supply an adequate amount of oil under pressure for the present purposes. As a result, the pressure in the power cylinder that is delivered from the power oil pipe 20 is the normal hydrostatic head of oil from the cylinder to the surface, plus whatever pressure isy superposed thereupon by thc pumping mechanism aforesaid. This pressure is constantly delivered from the power oil pipe 20 to the chamber 80, thence by the passage 81 to theV space 70 within the barrel 22. From this space it descends all the way down to just above 'the sucker rod pump connection, whence it can enter through the holes 66 into the lower cylinder 67 and act upwardly upon the effective lower area of the piston 37 which, as understood, equals the inside diameter of the cylinder or barrel 46 minus the outside diameter of the connecting rod 31. This pressure acting upon the lower surface of the piston thereby tends to move the piston upwardly, carrying with it the connecting rod 31 which, in turn, is connected down to the sucker rod projection 26 and ultimately to the sucker rod pump (not shown).

The foregoing is not to say that the mere existence of power oil pressure within the cylinder 67 `actually causes the piston to move upwardly because of conditions to appear. Whether or not the piston moves upwardly depends upon the conditions set by the valve apparatus.

In the position of the valves illustrated in Figure 1l, the mechanicalvalve 110 is in its neutral position, since it ibas ybeen actedupon andreleased. Its -la'st movement mum production oil unit pressure.

9. was downwardly, in which case it would have ported power oil from the port i) through the passage 144 to the upper valve chamber over the upper end of the intermediate valve 150. It correspondingly would have ported the lower valve chamber of the intermediate valve by way of the passage 143 and the passage 142 to the production oil at relatively low pressure, namely hydrostatic head of oil in the well. Since the power oil is at higher pressure, such action would have driven the intermediate valve to its lower position illustrated.

The lower position of the intermediate valve 150 ports power oil from the passages `10ft to the passage 160 and to the lower valve actuating chamber of the upper valve 170. At the same time, the upper actuating pressure chamber of the main valve 170 is connected by the passage 1 61 to the

return passages

165 and 140. This accounts for the upper position of the main valve 170 that causes the upper cylinder 71 to be ported to the return line. This condition is illustrated by the fact that the upper cylinder 71 is in continuous communication through centering spring'cage 48, spacer 50, and passage 140 to the passages 8S that are connected into the well casing.

When the foregoing condition exists, the motor piston is acted on by power oil pressure at its underside and well casing hydrostatic head pressure at its upper side. While the piston area on the lower side of the piston is less than that on the upper side, this is more than overcome by the excess of power oil unit pressure over maxi- Consequently, the piston is driven upwardly.

In the illustrations, the piston has'recently begun its upward movement, carrying with it the sucker rod. To

show the greater pressure below the piston, the arrows pointing upward in the cylinder 67 are solid; to show lesser pressure on greater area, the arrows pointing downward in the cylinder 71 are in 4broken lines but more numerous. A

As the piston 37 goes upwardly, it will carry the overtravel spring cage 39 upwardly with it, but it will not move the valve stem rod 120. Rather, it will reciprocate over that valve rod through substantially the whole stroke of the pump. This stroke may be in the order of five feet, for example. It is desirable to have suicient oil passage space around the valve stem parts to avoid great pressuredrop as the valve stem enters the oil-filled connecting rod and expels oil therefrom. In the illustrated design, the maximum pressure drop is about 2# as against l0# inthe spring 126.

As the piston approaches the upper eXtreme of its movement, the actuator'41 'will constitute an abutment to impinge upon the bottom end of the connector 121, which is secured to the rod 120, and which acts as a companion abutment. Thereafter, any further movement of the piston rod (which movement will continue until there'is a reversing of the valves) will elevate the sleeve 125, and the valve stem 111 and the valve 110, moving the mechanical valve 110 to its upper position. In so doing, the upper end of the collar 121 abuts and elevates the lower centering spring guide 126, elevating it against the spring 126. In the upper position of the valve 110, as already noted, it ports power oil to the lower operating chamber of the intermediate valve 150 to elevate that valve, which, in turn, causes delivery of power oil to the upper side of the main valve 170 driving that valve downward. When the main valve 170 is driven downward to its lower position, the cylinder 71 is connected to power oil by'way of the passage 102. This means that power oil is introduced by the passage 138 to the space below the valve body which is always in communication with the lupper cylinder 71.

vWhen the foregoing takes'place, pressure is built up above the piston 37 while, at the same time, the power oil pressure remains the same below the piston. Owing to the fact that the eiective area on the upper side of 1 'l0 the piston 37 is greater than that on the lower side, this admission of power oil pressure to the cylinder 71 causes the piston to start rnc-ving downwardly. Immediately it causes the actuator 41 to withdraw from the collar 121 so that the neutralizing or centering spring 126 may return the mechanical valve 110 to neutral position. However, the return of the valve `to neutral position merely provides a hydraulic lock on the intermediate valve, because in such position the lower actuating chamber of the intermediate valve is connected by way of the passage 143 to [the land 132 of the mechanical valve 110, at which point it is blocked and trapped. At the same time, the upper operating chamber of the intermediate valve is connected by the line 144 to the land 131 of .the mechanical valve 110, and is likewise hydraulically locked. By this arrangement, as soon as the mechanical pressure is relieved from the mechanical valve 110, it forthwith effects a hydraulic lock to hold the intermediate valve in the position to which it just previously has been moved. It, of course, will be under- 'stood that there is no mechanical relief on the mechanical valve until the main valve is shifted, because it requires a shift of the main valve to reverse the conditions of the motor so as to reverse the direction of movement of the piston. Also, the intermediate valve 150 vis assured of movement to its full eXtreme before the hydraulic lock upon it is rendered effective. This will assure that, regardless of whether the mechanical valve is again neutralized prior to full movement of the main valve 170, there will be full movement assured because of the position of the intermediate valve.

The piston will then descend, and after the first brief part of its movement .the valve stem will not be moved, but the piston will reciprocate over the valve stem.

When the piston approaches the lower end of its movement on a downstroke, which is a position more or less as illustrated, it will cause the retainer 41 to approach the nut 123 which acts as an abutment. At the extreme of such downward movement, contact will be effected between the retainer 41 and the nut 123, so that the subsequent small downward movement of the piston will cause the valve stern 120 to be lowered from its neutral position, establishing the sequence of reversing the action previously mentioned of all three valves, and again connecting the cylinder 71 with the return line at production oil pressure, while leaving power oil pressure below the piston 37 so as to reverse the direction of the piston and drive it upwardly again. After the rst brief pant of the upward movement of the piston as aforesaid, the mechanical valve will again be permitted to neutralize under the influence of the spring 126, providing the same hydraulic lock but with .the two upper valves in their opposite positions.

The foregoing represents the cycle of operation of the pump motor with itsV reversing valve apparatus. Since the pressure oil is always on the underside of the piston, and since there is a differential piston area, with mechanical valve reversals, the piston cannot hang up on dead center, even though no springs are provided. If, for example, the piston were on an upstroke, and it partly shifted the valves until pressure is partially admitted vinto the upper cylinder 71, a downstroke cycle is inevitable, because even the slowly entering pressure admitted through a partially shifted valve will ultimatelyV build up to provide the downstroke. The main valve passage 173 should have an axial length insufficient to connect the pressure passage 102 with the return passage 89.

It is valuable to have the anti-stall feature, without springs. And the same structure of the small upstroke area and `large downstroke area provides a relatively fast downstroke, which is the return stroke of the sucker pump.

Assembly Among the especial features of the present invention are details of the. arrangements for assembly and disassembly with minimum difficulty and a minimum diversity of tools.

Reference has already been made to the adjustment between the spacer`

tubes

24 and 241. The effect, which is accomplished by loosening the nut 40 and relatively moving the two

spacer tubes

24 and 241, is to shorten the outer barrel of the pump at its lower end without shortening the connecting rod 31. The overall result of this is to cause the pump piston rod of the sucker pump to move closer to the end of the pumping cylinder on the compression stroke. This has such advantages as the automatic purging of the pump in the event of a vaporization of the liquid being pumped.

This adjustment is readily accomplished by putting awrench around the spacer tube 241 at the opposed flats 64, and another wrench around the nut 40 to loosen Ithe same. Thereafter, the two spacer tubes may be relatively twisted to get the proper extension or contraction of the length, followed by tightening of the nut.

The reversing of the valve may be caused to occur only ait the extreme end of the movement of the pistonand hence of the sucker rod-by means of the adjustment of the two

nuts

122 and 123, or of the collar 121. Normally, there is no need for adjustment of the collar 121 because it represents the relatively unadjustable upward movement of the mechanical valve 110.

It is fairly evident that the overtravel spring 40 will prevent any undue strain on the parts should there be an overtravel before a shift can occur and in the event of maladjustment of sthe foregoing parts.

Ordinarily, in servicing the pump mechanism and motor, the rst thing to be done is to separate the sucker rod pump from the hydraulic motor. As the equipment is raised to the surface, an appropriate itool may be slipped around the proposed flats 64 in the lower spacer tube 241, which tube will extend outwardly so that the ap,- paratusV may be hung on the surface superstructure of the well. Then the joint between the sucker rod pump 25 and the lower tubular extension 241 may be separated. The pull rod 26 of the pump will remain attached to the` connecting rod 31 by the coupling 30.

The preferable way to proceed for separation of the pull rod 26 is to loosen the lock nut 40 and separate the lower tubular extension 241 from the upper tube 2,4. Then if the pump piston is pulled downwardly, the extension tube 241 may move to expose the coupling 30 which then may be separated from the tubular connecting rod 31. Thereupon, ithe sucker rod pump and the hydraulic motor are separated.

If it be desired then to service the inner mechanism of the pump, the preferred procedure involves, lirst, a removal of the upper head 21 by threading it out of the outer barrel 22. Thereupon, the lower coupling or packing retainer 23 can be removed and, if desired, drawn with any parts below it that are attached to it, off the lower end of the connecting rod 31, although this latter may not be necessary at that point. Then, preferably, a tool is applied within the outer barrel 22 to force outwardly upon the packing retainer and cylinder closure member 43. Or the member 43 may be removed downwardly and the tool applied against the inner barrel 46,

and also the rod 31. When these parts are pressedy upwardly, the inner barrel 46 abuts against the centering spring retainer 48 which, in turn, abuts against the sleeve member S of the valve so that all of those parts together are forced out the upper end of the outer barrel 22 and emerged therefrom successively. In this operation, itis also preferred to force the connecting rod 31 upwardly,

because it is not removable from the valve stem 120 and' therefore would cause a separation of parts within-the pumping and valving sections of the mechanism.

If the servicing is to be done upon the valving elements, these alone may be forced out the upper end of the outer barrel 2 2, and the valve, includingv its sleeve 55, withdrawn of the retainer 50. The mechanical valve does not necessarily move out with the valve body'. However, it may readily be removed from the head of the extension 111 by slipping it laterally through the

slots

114 and 115, when the spacer retainer 50 is pulled away from it.

The successively lower parts may be serviced in like manner by being forced out the upper end of the outer barrel 22. The retainer 50 may be lifted out of the retainer 43. The mechanical valve operating mechanism may be serviced by forcing the parts upwardly until the overcenter spring cage 39 projects and can be removed. This will free the lower collar 123 for removal, whereupon the valve stem is freed and all of the partsv may be removed, adjusted and serviced.

It is possible to separate the valve centering mechanism by removing the setscrew holding the valve stem portion 120 in the collar 121.

The foregoing illustrates how the parts of this hydraulic motor pump actuating means may be disassembled for servicing. The reassembly constitutes an obvious reversal of the disassembly above described. It is also apparent how the various packing elements may be replaced in disassembly and reassembly process.

Thus, in general, there are three parts to the whole pump apparatus. There is the lower sucker rod pump subassembly not illustrated, but merely represented inthe drawings. There is the hydraulic actuating motor, and there` is the control valve. The sucker rod pump can be removedfrom the lower end of the actuating motor, and the valve can be removed from the upper end of the actuating motor. Finally, the actuating motor itselfv may be. disassembled by being drawn out of its barrel.

By the foregoing description, it is not intended toV restrict the order of assembly or disassembly, or to require that it be. through the upper end of the barrels other'than is obviously necessary from the constructions involved. However, the fact that the assembly may be made largely through the upper end of the barrel constitutes a valuable feature. of this arrangement.

What is claimed is:

l. In a well pump: a power cylinder; a piston reciprocable therein and provided with a tubular cage; valve means to control flow of fluid under pressure to the piston to effectv reciprocation of the piston, the valve means.

including a valve movable in the same directionsasithe piston; a valve stem coaxial with the piston and extendingv into the tubular cage of the piston; first abuttable elements .on piston and stern within the piston comprising a ring-like retainer to be engaged at the end of a stroke in vwhich the piston moves in a first direction to withdraw from' the stem, the elements preventing such withdrawal; second abuttable elements on piston and stem comprising a collar tor be engaged at the end of an opposite stroke when thepiston moves in its second direction; and yieldable means including a spring surrounding the stem and yieldably holding the retainer a maximum distance toward the collar so as to resistingly yield when the elements are abutted as aforesaid, to permit overtravel of the piston relatively to the valve.

2. The combination of claim l, wherein there are two such ring-like retainers surrounding the stem and within the cage, constituting two of the abuttable elements; wherein the spring acts to separate them the maximum distance permitted by the cage; and wherein the retainer opposite the collar projects from the cage to engage with the other abuttable element on the stem.

3. In a motor usable in a well for a reciprocable pump: a longV outer tubular barrel; a head thereon having a power fluid passage leading therethrough to the inside of the barrclfadjacent-the wall-thereof, and a production fluid-passage leadingv from outside the upper part of the pump to the inside of the barrel at the middle part of the top; a cylindrical valve device attached to the head to conn-ect the production fluid passage into the valve and to separate off the power iluid passage to outside the valve; closure means at the lower end of the outer barrel; an inner barrel within the outer barrel below the valve device; means connecting the upper end of the inner barrel and the valve providing communication with the lower end of the valve device and the inside of the inner barrel, there being a power iluid space between the outer and inner barrel connecting with a space between the outer barrel and valve device and with the power uid passage; ports through the inner barrel adjacent the lower end; a piston in the inner barrel with a connecting rod depending therefrom and extending through the closure means, the valve having means including a valve movable up and down, to alternately connect the upper side of the piston with the power uid passage and the production uid passage, the piston having different areas above and below; a Valve stern depending from the movable valve and into the piston; and two pairs of spaced abutment means between the valve stem and the piston to cause movement of the valve when the piston reaches the two extremes of its strokes.

4. The combination of claim 3, wherein the outer barrel is separable from the head and the lower closure; and wherein the valve device, the inner barrel, and the means connecting them are releasably clamped between the head and the lower closure, and may be ejected from the end of the outer barrel when the head is removed.

5. In a motor usable in a well for a reciprocable well pump: an outer barrel; a removable barrel head; a removable lower barrel closure; a valve device in the barrel; an inner barrel containing a piston within the outer barrel; and means connecting the inner barrel and valve device and connecting means in axial alignment within the outer barrel to hold them rigidly in place, and the aligned parts aforesaid being removable through the end of the outer barrel when the head and closure are removed.

6. The combination of claim 5, with a valve stem depending from the valve device to the piston, and spaced pairs of abutment elements between the piston and stem to provide movement of the stem at the ends of the strokes of the piston.

7. The combination of claim 6, with the connecting means between the valve device and the inner barrel comprising a centering spring cage; a pair of axially spaced opposed xed abutments within the cage; and a pair of opposed, substantially equally spaced abutments on the stem, a pair of opposed spring guides surrounding the stem and a spring urging them apart, the gui-des being normally, yieldably engaged with the opposed abutments on the stem and fixed.

8. In a motor usable in a well for a reciprocable pump: an outer barrel; a motor cylinder and piston in the barrel; a connecting rod depending from the barrel; a spacer tube device depending from the barrel around the connecting rod; and connections for removably attaching a sucker rod pump at the bottom of the spacer tube device and for removably attaching a pull rod of the pump to the connecting rod of the motor, the spacer tube device including telescopic adjusting parts by which the length of the spacer tube may be adjusted without changing the length of the connecting rod and pull rod.

9. In a motor usable in a well for a reciprocable pump: an outer barrel; a motor cylinder and piston in the barrel; a connecting rod depending from the barrel; a spacer tube device depending from the barrel around the connecting rod; connections for removably attaching a sucker rod pump at the bottom of the spacer tube device and for removably attaching a pull rod of the pump to the connecting rod of the motor, the motor cylinder comprising an inner barrel separate from the outer barrel; a valve device above the inner barrel; and removable parts closing the ends of the outer barrel, the pump and motor device being connectible by connecting the tubular extension of the outer barrel to the pump and the connecting rod to the pull rod, and the valve device and inner barrel being separable from the tubular extension upon removal of a removable part for closing the end of the outer barrel.

l0. In a pump motor for a well: an outer barrel having means at its lower end for connection to a pump; a fluid cylinder and piston in the outer barrel providing uid pressure chambers above and below the piston; a valve device above the piston including a valve stem depending from the device, the stem extending down to the piston and being connected against removal therefrom; one having a head and the other having a laterally open slot into which the head may be slipped to be held against separation by axial forces; and means rigid with the barrel to hold the parts against lateral movement that would separate them.

References Cited in the file of this patent UNITED STATES PATENTS 1,765,921 Joy June 24, 1930 2,039,570 Thornton May 5, 1936 2,060,180 Davis Nov. 10, 1936 2,273,349 Farley et al Feb. 17, 1942