US2522825A - Two-zone pump - Google Patents

Description

TEMPLE R HOFFER INVENTOR.

ATTORNEYS 3 Sheets-Sheet 1 T P HOFFER TWO-ZONE PUIP FIG.2

FIG.E

Sept. 19, 1950 Filed Nov 4, 1946 R m. 5 2 \\H@ E i4 MR m a t 2 9w 8 5 WNGM m u a wjmw v CM em 4m MM w x V 9 v A 9m t a B 3 W 3% T h S 3 II I FIG. 5 My T. P. HOFFER TWO ZONE PUIP Sept. 19, 1950 Filed Nov. 4, 1946 Sept. 19, 1950 Filed Nov. 4, 1946 T. P. HOFFER TIC-ZONE PUMP 3 Sheets-Sheet 3 Temp/e Hoffer INVENTOR.

Patented Sept. 19, 1950 TWO-ZONE PUMP Temple 1'. Hoi'fer, Dallas, Tex., assignor to Otis Pressure Control, Inc., Dallas, Tex., a corporation of Delaware Application November 4, 1946, Serial No. 707,653

14 Claims.

1 This invention relates to improvements in well production apparatus and refers more particularly to apparatus or equipment for separately producing fluid from two producing formations through a single well bore.

In wells having multiple producing formations it is usually desirable to produce from the formations separately without commingling the fluid from the formations. Obviously this should be accomplished by using conventional equipment as far as possible.

It is further desirable that the apparatus permit flow from either of the formations while flow is induced from the other formation by means of pumps, gas lift or the like. To accomplish these ends two flow passages must be provided within a well bore, each of the passages communicating with one of the producing formations with means for inducing flow of fluid separately in each of the passages.

An object of this invention is to provide for a well bore having two producing formations apparatus for conducting fluid to the surface wherein the casing tubing annulus is utilized as a conduit for fluid from one formation and the tubing for fluid from the other formation,

Another object of this invention is to provide apparatus for a well bore having two producing formations apparatus for conducting fluid to the surface wherein the casing tubing annulus is utilized as a passage for fluid from one formation and the tubing sucker rod annulus for fluid from the other formation, wherein means may be provided for inducing flow of fluid through each annulus.

A further object is to provide pumping apparaproducing formation tus for wells having multiple producing formations wherein a single sucker rod string may be utilized to induce flow from the formations.

Yet another object is to provide pumping apparatus for wells having multiple producing formations wherein a single sucker rod string may be utilized to produce from the formations and the sucker rod string may be of conventional type substantially throughout its length.

Yet a further object is to provide apparatus of the type described in which the tendency of the pump to gas lock is eliminated.

Other and further objects of this invention will appear from the following description:

In the accompanying drawings which constitute a part of the instant specification and are to be read in conjunction therewith and wherein like reference numerals are used to indicate like parts in the various views;

Figs. 1, 2 and 3 are complementary sectional views of the lower portion of a well bore communicating with two producing formations which is equipped with apparatus embodying this in-, vention;

Fig. 4 is an enlarged detail of the annular traveling valve and a portion of the hollow plunger of the apparatus shown in Fig. 2;

Fig. 5 is an enlarged detail of the packer and standing valve in the tubing-hollow rod annulus illustrated in Fig. 2; and

Fig. 6 is a vertical sectional view of the complete apparatus installed in a well bore.

Referring to the drawings, numeral Hi designates a well bore extending downwardly through the upper producing formation II and the lower II. The well bore is equipped with an oil string of casing It and a string of flow tubing it. The oil string of casing and the flow tubing are perforated or may have other suitable means of communication with the producing formations II and 12.. A rod string is mounted for reciprocation within the tubing and is made up principally of two sections. The usual solid sucker rod string [5 extends downwardly from the ground surface to a level somewhat above the upper producing formation. At its lower end the solid sucker rod string l5 carries a hollow polished rod section IS. The hollow section l6 communicates at its lower end with the lower producing formation through the lower end of the flow tubing. This hollow rod section also communicates at its upper end with the interior of the flow tubing and suitable means for accomplishing this is shown in Fig. 1 wherein a perforated collar or cross-over connection I1 is illustrated as a coupling member between the solid rod string and the hollow rod section.

It will be understood that with the apparatus thus far describedboth the producing formations are in communication with the interior of the casing, tubing and hollow rod section. Thus, it is necessary to divide the annular spaces between the casing and tubing and tubing and rod string into separate chambers in order to provide separate flow passages for fluid from the two producing formations. Preferably each of the annular spacesare divided into upper, lower and intermediate chambers. Conventional packers it are provided for the casing tubing annulus atlevels above and below the upper producing formation. Thev tubing I4 is perforated at Ma above the upper packer l8.

Due to the arrangement thus far described fluid from formation ll communicates with the interior of the casing intermediate packers l8 and may pass through the tubing perforation 4| into the interior of the tubing and through ports a into the interior of the casing above the upper packer. In order to separate this flow passage from fluid from the lower producing formation packers l9 and 20 are placed in the annulus between the tubing and hollow rod section. Packer I9 is located adjacent and above perforations I la while packer 20 is positioned adjacent and below tubing perforations 4| communicating with the interior of the casing intermediate packers l8. Thus a sealed flow passage is provided from the upper producing formation to the upper chamber of the casing tubing annulus and the fluid may then flow to the ground surface through this annulus.

By reference to Figs. 1, 2 and 3 it will be seen that there has also been provided a separate flow passage for fluid from the lower formation [2 to the ground surface. This passage includes the lower end of tubing I4 the interior of the hollow polished rod section I 6 and the interior of tubing l4 above the upper packer I 9. The fluid may then flow to the ground surface through the tubing sucker rod annulus.

If both the producing formations H and I2 are capable of natural flow further apparatus is not required in the well bore. However, after the wells are produced for a prolonged period it usually becomes necessary to employ means for inducing flow from either or both of the formations. According to this invention this may be readily accomplished by utilizing the sucker rod string and polished rod section as an actuating rod for a plunger or other type pump or pumps operable to force fluid through both of the fluid passages heretofore described.

To induce flow from the lower formation the lower end of the hollow polished rod section it carries a part with an enlarged diameter as shown at 2i. This part has a close fit with the inner surface of a section of tubing Md which is finished inside to provide a pumping cylinder and upon reciprocation of the sucker rod string part 2! serves as a plunger. This plunger is equipped with a traveling valve which may comprise a ball 22 operable with seat 23. The usual standing valve 24 is located in the interior of tubing I, at a point intermediate the lower tubing perforations and the lower end of the pumping cylinder d. Thus upward movement of plunger 2! draws fluid past the standing valve 25. The standing valve is then seated on the downward movement of plunger 2| and fluid above the standing valve is permitted to flow through the traveling valve 22. On the next upward stroke of plunger 2| the fluid above the traveling valve is raised and thus continued reciprocation induces flow of fluid from the lower formation through the hollow rod section It and into the interior of tubing l4 above packer i9 and thence to the ground surface.

The same rod string is preferably utilized to actuate a plunger and traveling valve assembly operable in the annular chamber within the tubing intermediate packers i9 and 20 and above the tubing perforations communicating with formation II, in a section of tubing Me which is finished inside to provide a second pumping cylinder. An annular standing valve is also provided to cooperate in the usual fashion with the plunger and traveling valve. This mechanism is detailed in Figs. 4 and 5.

Referring now to the annular traveling valve shown in Fig. 4, it will be seen that the hollow rod section l6 has a tapered portion |6a which has a press fit with an annular ring 25 which constitutes the traveling valve seat. This ring may be connected to the rod section I6 in any suitable manner. The ring 25 has vertical ports 25a to establish communication past this member. Ring valve 26 fits loosely over" the hollow section I6 and has a tapered seating surface corresponding to the seating surface of ring 25. Thus, with the pressure differential across ring 25 tending to produce flow upwardly through the tubing, ring 28 is unseated. However, when the pressure differential tends to cause downward flow through the tubing, ring valve 26 is seated to close the valve.

The plunger includes a hollow member 21 which is carried by ring 25. Member 21 has a close fit with the interior of the tubing as will be understood by those skilled in the art.

With regard to the standing valve detailed in Fig. 5 it comprises an annular seat member 28. The seat member has a sliding fit on rod mm P tion l6 and is anchored to the tubing in a manner to be hereinafter described. The seat member has ports communicating with perforations in tubing l4 and with the annular space within tubing I4 and above member 28. Flow through the ports is controlled by an annular valve member 33 loosely carried by rod section I6. Valve member 33 has a seating surface cooperable with that of seating member 28. A seal is provided between the member 28 and tubing I 4. This may be suitably accomplished by use of chevron type packing rings 29, spacer rings 30 and 3! and gland nut 32.

The standing valve assembly just described is preferably connected to packer unit 20 and with the packer is adapted to be anchored in proper position within tubing M. This packer unit includes a carrier sleeve 34 having a portion of reduced diameter threaded into the lower end or the bore through member 28. Suitable seal rings such as chevron type packing material 35 is secured about the portion of reduced diameter of member 34 and is held in place between shoulders 33a of the packer carrier and the lower end of seat member 28. Spacer rings may be employed in this packer assembly as shown. It is to be understood that any suitable packing material or assembly may be used in this connection. Can'ier 34 also is provided with packing material 36 carried by a portion of its bore of enlarged diameter to provide a sliding seal about hollow rod section IS. The packing and suitable spacer rings are held in place in the bore by means of gland nut 31. Thus it will be seen that the annular space between tubing [4 and rod section l8 has been effectively sealed off.

In order to anchor the packer 20 and its associated standing valve within tubing 14 an annular groove Mb is provided within the tubing spaced at a predetermined position below the tubing perforations which communicate with the upper producing formation. Anchor rods 38 are carried by nut 31. These rods have lugs 38a adapted to engage groove b as shown in Fig. 5. Grooves Mb have a greater width than the space between the joints of tubing l4. Lugs 38a are longer than the space between adjacent joint ends of tubing I 4 whereby in passing the sucker rod downwardly through the tubing the lugs 38a will not engage the grooves between the tubing ends of adjacent joints but will engage the groove Mb. The hollow rod section It has secured thereto an annular element 38 having a tapered surface 39a which is adapted to engage the lower inturned downwardly extending portion of anchor rods 38. If it is desired to release the anchoring means for racking 20, the rod string is lifted until element 39 engages the lower ends of rods 38. This collapses rods 38 to disengage lugs 38a from groove 1422. Continued upward movement of the rod string then serves to withdraw the rod string and packing unit from the tubing. When the rod string is lowered into the tubing, axial movement of packer 20 and the associated standing valve is limited by engagement with the coupling member between adjacent joints of the hollow rod section It.

Packing i9 may be made up the same as packing 20 except that a suitable gland nut is used in conjunction with the upper end of the packing carrier to collapse packing 35 instead of the seat ring member 28. This packer carries anchoring rods 40 with lugs 40a adapted to engage a groove l4c in the tubing just above the perforations l4a of the tubing. The width of groove I40 and the length of lugs 40a are greater than the width of the space between adjacent tube joint ends so that the lugs 40a do not engage the tubing joint ends in lowering or withdrawing the rod string intoor from tubing 14.

However, groove Me is somewhat narrower than the length of lugs 38a. associatedwith the anchor for packer 20, whereby lugs 38a. willpass groove I40 as the'rod string is. moved" axially within tubing l4. A second element 39 1con nected to the rod string, serves'to*release .the

anchor rods 40.

It is believed that the assembly .andyopera-j tion of the device is obvious from the;foregoing description. Conventional solid sucker rods are utilized except for the hollow rod section i6,

the well bore, reciprocation of the rod string actuates the hollow plunger 2| and its associated traveling valve to cause upward flow of fluid from the lower formation through the hollow rod section and into the tubing sucker rod annulus above the upper packer [9. This flow then continues to the ground surface through the: tubing and is separate from the flow through the upper producing formation H. Fluid from the upper formation is simultaneously pumped through the annular chambers between the casing and tubin; and the tubing andhollow rod and back into the casing tubing annulus above the uppermost packer i8. Reciprocation of the rod string actuates the plunger and traveling valve assembly including sleeve 21, seat ring 25 and valve 28. The fluid is drawn past the standing valve including seat 28 and ring valve 33 when the rod string moves upwardly. On downward movement of the rod string the standing valve is closed and fluid passes through ports 25a and past ring valve 26 of the traveling valve.

It is contemplated that this arrangement of pumping apparatus may be used in wells wherein fluid from either or both the producing formations flows partially under pressure within the particular formation. The traveling and standing valves in each of the passages leading from the producing formations will in no way interfere with upward fluid flow from any connection. It is further contemplated that a different type of plunger or non-plunger pump may be employed with the flow arrangement described;

which extends from a, point above packer IE to the plunger 2| just above the lower formation l2 of the well bore. The tubing and easing are of the conventional type with the exception of the grooves Nb and Me in appropriate tubing joints and the sections finished to provide pumping cylinders. The perforations of the tubing, such as at Ma, may be made in any manner customary to the well producing art. The hollow rod section I6 is assembled with the plunger 2| connected to its lower end. This plunger carries the traveling valve associated therewith and the standing valve 24 is secured within the well tubing before it is lowered into the casing. The packer 20, ring seat 28 and ring 33 are assembled on the hollow rod section as is the plunger, traveling valve assembly, including sleeve 21, seat 25 and ring valve 26. The rod string may then be lowered into position within tubing 14 and when anchor rods 38 and 40 reach the grooves 14b and He, respectively, in the tubing, the lugs engage the grooves to secure the packing assembly within the tubing. These anchor rods may be released. to permit withdrawal of the rod string, by lifting up on the rod strin'n This raises elements into engagement with the lower ends of anchor rods 38 and 40 to release lugs 38a and 40a from engagement with grooves Nb and I40, respectively.

The packers I! which separate the casing tubing annulus into separate chambers may be of any conventional type now employed in-the industry.

In operation, with the apparatus assembled in not in a limiting sense.

in will'be seen that the objects of the invention'whave been accomplished. There has been .providedjseparate-flow passages communicating between the two producing formations and the ground surface whereby there is no commingling .of the fluids from the formations.

The fluid may flow naturally from either formation, where this is possible, and the construction is such that separate flow inducing means may be utilized in one or both of the passages. The arrangement is such that reciprocation of a single rod string, which is conventional throughout most of. its length, may be utilized to simultaneously actuate pumps in each of the flow passages.

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 togather with other advantages which are obvious and which are inherent to the structure.

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

As many ossible embodiments may be made of t e invention without departing from the scop 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 Having described my invention, I claim: 1. In a well bore communicating with two producing format ons, an oil string of easing, a flow tubing withinthecasing. a solid sucker rod string mounted for reciprocation withinthe tubing. a hollow rod section on the solid sucker rod stri g. means dividing the annular spaces between the rasing and tubing and the tubing and hollow rod section into separate-chambers means establishing communication between certain of the chambers and between the hollow-rod section trol flow through said separate passages upon reciprocation of the hollow rod.

2. In a well bore communicating with two producing formations, an oil string of casing, a flow tubing within the casing, a solid sucker rod string mounted for reciprocation within the tubing and means associated with the casing, tubing and sucker rod dividing the annularspaces therebetween into separate flow passages from the producing formations whereby fiuid from one formation flows through the upper portion of the casing to the ground surface and fluid from the other formation flows through the upper portion of the tubing to the ground surface, said means including a rollow rod section connected in the sucker rod string and forming a part of the passage which includes the upper portion of the tubing, and means carried by the hollow rod section for simultaneously inducing flow through said passages.

3. In a well bore communicating with two producing formations and equipped with an oil string of easing, a flow tubing within the casing and a solid sucker rod string reciprocally mounted within the tubing, said sucker rod string carrying a hollowrod section; packer means dividing the spaces between the casing and tubing and the tubing and hollow rod section into upper, lower and intermediate chambers; ports in the tubing and casing placing said intermediate chambers and the upper casing chamber in communication with each other and one of the producing formations, providing a flow passage for fluid from this formation to the ground surface; said hollow rod section communicating with the other formation and upper tubing chamber and providing a flow passage for fluid from this formation; and means having an actuating connection with the hollow rod section for controlling and inducing flow separately from said formations.

4. In a well here communicating with two producing formations and equipped with an oil string of easing, a fiow tubing within the casing and a solid sucker rod string reciprocally mounted within the tubing, said sucker rod string carrying a hollow rod section; packer means dividing the spaces between the casing and tubing and the tubing and hollow rod section into upper, lower and intermediate chambers; port means in the tubing and casing placing said intermediate chambers and the upper casing chamber in communication with each other and with the upper producing formation and thus providing a flow passage for fluid from this formation to the ground surface; said hollow rod section communicating with the lower formation and upper tubing chamber and thus providing a part of a flow passage for fluid from this formation; and means having an actuating connection with the hollow rod section for controlling and inducing flow separately from said formations.

5. In a well bore communicating with two producing formations and equipped with an oil string of casing, a flow tubing within the casing, and a solid sucker rod string reciprocally mounted within the tubing, said sucker rod string carrying a hollow rod section; packer means dividing the spaces between the casing and tubing and the tubing and sucker rod string into upper, lower and intermediate chambers; ports in the tubing and casing placing said intermediate chambers and the upper casing chamber in communication with each other and the upper producing formation, and thus providing a flow passage for fluid from this formation to the ground surface; said hollow rod section communicating with the lower formation and upper tubing chamber and thus providing a flow passage for fluid from this formation; and two pumping assemblies operably associated with the sucker rod string and hollow rod section for controlling and inducing flow separately from said formations, said assemblies each including a plunger, traveling valve and standing valve.

6. In a well bore communicating with two producing formations and equipped with an oil string of casing, a flow tubing and a solid sucker rod string mounted for reciprocation within the tubing, a hollow rod section carried by the sucker rod string, perforations in the casing and tubing placing the upper producing formation in communication with the interior of the tubing, casing packers between the casing and tubing on both sides of the perforations and upper formation, two tubing packers between the tubing and hollow rod section, one of these packers at a level above the upper casing packer and the other at a level below said tubing perforations, ports in the tubing communicating with the casing above the upper casing packer and below the upper tubing packer, standing and traveling valves controlling flow through the tubing between the ports, said traveling valve operably mounted on the hollow rod section, said hollow rod section slidably extending through the tubing packers, the interior of said hollow section communicating at one end with the interior of the tubing above said tubing packers and at the other end with the lower producing formation, and standing and traveling valves controlling flow through said hollow rod section.

7. As a subcombination an elongated tubular member, a hollow rod section mounted for reciprocation within the tubular member, two packers removably anchored between the member and hollow rod section, one of the packers located adjacent but below the upper end of the hollow section and the other located intermediate the ends of the hollow section, ports in the tubular mem ber adjacent and intermediate the packers, a plunger, traveling valve and standing valve associated with the hollow section and adapted to induce flow upwardly therethrough, a second plunger, traveling valve and standing valve associated with the hollow section exterior thereof, within the tubular member and between the packers, the latter plunger traveling valve and standing valve adapted to induce and control flow upwardly through the tubular member intermediate the ports.

8. As a subcombination a unit adaptable for use in a well bore equipped with a well tubing and casing, said unit comprising a hollow rod section having openings at both ends and adapted to be connected to a solid sucker rod string, a plunger at the lower end of said hollow section, a traveling valve associated with the plunger and adapted to control flow through the plunger and section, two spaced apart packers mounted on said section an annular plunger secured to the hollow section exterior thereof and a traveling valve associated therewith adapted on installation of the hollow rod section within the well tubing to control flow through that portion of the tubing and past said valves, said annular plunger and traveling valve located intermediate the packers.

9. As a subcombination a unit adaptable for use in a well bore equipped with a well tubin and casing, said unit comprising a hollow rod section having openings at both ends and adapted to be connected to a solid sucker rod string, a plunger at the lower end of said hollow section, a traveling valve associated with the plunger and adapted to control flow through the plunger and section, two spaced apart packers mounted on said hollow section, an annular plunger secured to the hollow section exterior thereof and intermediate the packers, a traveling valve associated with the plunger, a standing valve slidable on the hollow section intermediate the packers, said plunger and valves adapted on installation of the unit within the well tubing to control flow through that portion of the tubing between the packers and p 1 the valves.

10. In a well bore communicating with two producing formations, a string of casing, a string of tubing within the casing, a string of solid sucker rod mounted for reciprocation within the tubing, a hollow-rod section secured to the lower end of the sucker rod, and means including packers and ports dividing the interiors of the casing, tubing and hollow-rod section into two separate passages for producing well fluids from the formations without commingling the fluids, one part of one of the passages including the interior of the hollow-rod section and one part of the other passage including at least a part of the space between the tubing and hollow-rod section.

11. In a well bore communicating with two producing formations, a string of easing, a string of tubing within the casing, a string of solid sucker rod mounted for reciprocation within the tubing, a hollow-rod section secured to the lower end of the sucker rod, means including packers and ports dividing the interiors of the casing, tubing and hollow-rod section into two separate passages for producing well fluids from the formations without commingling the fluids, one part of one of the passages including the interior of the hollow-rod section and one part of the other passage including at least a portion of the space between the tubing and hollow-rod section, and two means carried by the hollowrod section and residing respectively within the latter parts of the two passages for inducing and controlling the flow therethrough upon reciprocation of the hollow-rod section.

12. In a well bore communicating with two producing formations, a string of casing, a string of tubing within the casing, a solid sucker rod string mounted iorreciprocation within the tubing, a hollow-rod section secured to the lower end of the sucker rod, means including packers and ports dividing the interiors of the casing, tubing and hollow-rod section into two separate passages for producing well fluids from the formation without commingling the fluids, one part of one of the passages including the interior of the hollow-rod section and one part of the other passage including at least a part of the space between the tubing and hollow-rod section, and two travelingand standing-valve assemblies associated with the hollow-rod section for con- 10 trolling fluid flow from the two formations, one traveling valve residing within the hollow-rod section and the other traveling valve surrounding the hollow-rod section.

13. In a well bore, communicating with two producing formations, a string of easing, a string of tubing within the casing, said strings extending substantially to the lower formation, two packers between the casing and tubing, one of the packers above the upper producing formation and the other located intermediate the formations, a solid sucker rod mounted for reciprocation within the tubing, a hollow-rod section carried at the lower end of the sucker rod, packer means carried by the hollow-rod section adapted to be releasably anchored within the tubing to provide seals between the tubing and hollow section, said packer means mounted upon the hollow section in such manner that the packer means may be lowered into and withdrawn from anchored position within the tubing by axial movement of the hollow-rod section, port means in the casing, tubing and hollow-rod section providing, together with the casing tubing annulus, the tubing hollow-rod annulus, tubing suctionrod annulus and the interior of the hollow-rod section, separate flow passages for separately conducting well fluids from both producing formations.

14. In a well bore, communicating with two producing formations, a string of casing, a string of tubing within the casing, said strings extending substantially to the lower formation, two packers between the casing and tubing, one of the packers above the upper producing formation and the other located intermediate the formations, a solid sucker rod mounted for reciprocation within the tubing, a hollow-rod section carried at the lower end of the sucker rod, packer means carried by the hollow-rod section adapted to be releasably anchored within the tubing to provide seals between the tubing and hollow section, said packer means mounted upon the hollow section in such manner that the packer means may be lowered into and withdrawn from anchored position within the tubing by-axial movement of the hollow-rod section, port means in the casing, tubing and hollow-rod section providing, together with the casing tubing annulus, the tubing hollow-rod annulus, tubing suctionrod annulus and the interior of the hollow-rod section, separate flow passages for separately conducting well fluids from both producing formations, and two traveling valve means carried by the hollow section, residing in the separate flow passages respectively, and removable with the hollow-rod section for inducing flow of fluids from both formations upon reciprocation of the hollow-rod section.

TEMPLE P. HOFFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 967,498 Clark Aug. 16, 1910 1,870,137 Parker Aug. 2, 1932 2,281,899 White May 5, 1942 Disclaimer 2,522,825.-Temple P. H offer, Dallas, Tex. Patent dated Sept. 19, 1950. Two- ZONE PUMP. Disclaimer filed J an. 21, 1952, by the inventor and the assignee, Otis Pressure Gantrol, I no.

Hereby enter this disclaimer to claim 1 of said patent.

[Ofiicial Gazette Febmm'y 19, 1.952.]

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