US2850099A

US2850099A - Well production apparatus

Info

Publication number: US2850099A
Application number: US348173A
Authority: US
Inventors: Cicero C Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-04-13
Filing date: 1953-04-13
Publication date: 1958-09-02
Anticipated expiration: 1975-09-02

Description

WELL PRODUCTION APPARATUS 5 Sheets-Sheet 1 Filed April 15. 1953 C/ce/"o C. Brown- INVENTOR.

4 TTORNE m v Sept. 2; 1958 c. c. BROWN 2,850,099

WELL PRODUCTION APPARATUS Filed April 13. 1953 I 5 Sheets-Sheet 2 (were C. Brown a INVENTOR.

K6 Mq f1 TTORNEVd- Sept. 2, 1958 Filed April 13. 1953 C. C. BROWN WELL PRODUCTIONAPPARATUS 5 Sheets-Sheet 3 Innwmvm C/C'ero C. Brown INVENTOR.

Sept. 2, 1958 Filed April 15. 1953 \v 4 320 v /z -J2 y\ M g Q,

c. c. BROWN WELL PRODUCTION APPARATUS 5 Shets-Sheet 4 flj.4.0 i $5 C/cero C. Brown INVENTOR.

ATTORNEY YJ Sept. 2, 1958 c. c. BROWN WELL PRODUCTION APPARATUS 5 Sheets-Sheet 5 C/cero C. Brown INVENTOR. BY WWW/M21;

Filed April 13, 1953 WELL PRODUCTION APPARATUS Cicero C. Brown, Houston, Tex, Application April 13, 1953, Serial No. 348,173

14 Claims. v(Cl. 166-127) This invention relates to new and useful improvements in well packers.

It is an object of this invention to provide an improved well packer for sealing ofi an 'upper and a lower well formation wherein the packer is so constructed that production from the formations or other operations on the formations can be performed after the packer has been set without the necessity of pulling or removing the tubing associated with said packer.

It is an important object of this invention to provide an improved well packer for dual production from an upper and a lower well formation wherein the packer is constructed to receive a separate tubing string for each of the formations, whereby production of oil and other operations in connection with each formation can be conducted separately without the necessity of removing the tubing strings from the well bore and without permitting oil or other fluids passing to or from the formations from entering the casing whereby the casing annulus can be utilized for gas lift purposes.

It is another object of this invention to provide an improved well packer having a lower packing unit disposed between the lower well formation and an upper well formation and an upper packing unit disposed above the upper formation, the packer units each having communication with a separate tubing string extending to the surface of the well, the tubing strings having means for establishing fluid communication therebetween which is capable of being opened or closed without removing either tubing string from the well bore.

A further object of this invention is to provide in a dual production well packer which is adapted to be lowered into a well casing, a coupling member which is adapted to be connected at one end to a pair of tubing strings which extend to the surface of the well and which is adapted to be connected at its other end to concentrically arranged tubes in the packer units, whereby fluid may flow from the concentric tubes through the coupling member and into the pair of tubing strings thereabove to the surface of the well without entering the casing above the packer so that the casing annulus can be utilized for gas lift purposes.

United States Patent The construction designed to carry out the invention will be hereinafter described together with other features thereof.

The invention will be more readily understood from a reading of the following specifications and by reference to the accompanying drawings forming a part thereof,

wherein an example of the invention is shown, and

I Patented Sept. 2, 1958 "ice 2 tubing strings to close off the flow from the lower formation and to direct the flow from the upper formation through both of the tubing strings.

Figures 4A, 4B, 4C, 4D, 4E, and 4F are consecutive views, partly in elevation and partly in section, illustrating the details of the complete packer of this invention, from the upper to the lower end of the packer, respectively.

Figure 5 is a view, partly in elevation and partly in section, of a portion of the coupling member of the packer of this invention with a straight opening plug therein. I

In the drawings, the letter 'P designates the lower packer unit of the improved well packer of this invention, which. unit is disposed in a well casing C between a lower well formation A and an upper well formation B. Above the lower packer unit P, is a second or upper packer un it E which is adapted to be set in the well casing C above the upper formation B. A flow tube 10 extends through both the upper and lower packer units and has connection with a coupling member 11 disposed above the upper packer unit E. An inner flow tube 12 is concentrically disposed within the upper portion of the outer flow tube 10 with an annular space 16 formed therebetween and is connected with the lower end of the coupling member 11.- The coupling member 11 is connected at its upper end with a pair of

tubing strings

14 and 15 which extend to the surface of the well and are mounted in a tubing head, as will be explained. When the packers P and E are set in the casing C, the lower formation A flows upwardly through the flow tube 10 and thence through the inner flow tube 12 into the tubing string 15, while the fluid from formation D flows into the annular space 16 between the outer flow tube 10 and the inner flow tube 12 upwardly through the coupling member 11 to the tubing string 14. As will be explained, this normal flow from the formations to-the

tubing strings

14 and 15 can bechanged by'the use of various types of plugs which are adapted to be disposed within the coupling member 11. x V

The details of the complete dual production packer of this invention are illustrated in Figures 4A-4F. Figures 4E and 4F illustrate the lower packer unit P which is of the wire line type as disclosed in my co-pending- U. S. patent application Serial No. 260,859, filed December 10, 1951, now Patent No. 2,739,651. This packer P-is initially lowered into the well casing C on a wire line lowering or running-in tool prior to the time that the remainder of the dual packer of this invention is lowered into the casing. Thereafter the wire line lowering tool is removed leaving the bore of the packer unit P open for the reception of the flow tube 10. This lower packer P includes an upper seal cup 17 which has a radially expansible annular sealing member 18 connected therebelowt The annular expansible sealing member 18 is connected to a conical slip expander 19 which co-acts withgripping slips 20 which are carried by a sleeve 21 provided with frictional springs 22 for engaging the well casing C; The conical slip expander 19 has a plurality of radialpins 23 extending outwardly therefrom and into corresponding vertical slots 24 in the sleeve 21 to permit-relative longitudinal movement of the expander 19 with respect tothe slips 20 for moving the slips 20 radially into anchoring engagement with the interior of the well casing C. Below the gripping slips 20 a conical expander 19a is disposed which is in a reversed position compared to the upper expander 19 but is otherwise identical in construction. Such lower expander 19a has a plurality of radial pins 23a which extend through corresponding vertical slots 24a in the slip carrier or sleeves 21. A The lower end of the lower expander 19a has connection with a sealing cup 17a which is identical in construction with the upper sealing cup 17 but is in a reversed position. This packing unit P shown in Figures 4E and 4F is adapted to be set by a differential in well pressure above and below the unit. When such differential occurs, the sealing elements 17 and 17a are urged toward each other to thereby urge the expanders 19 and 19a toward each other to radially move the gripping slips 20 into a gripping engagement with the interior of the well casing C. The packing unit P includes a radially movable latch 26 which includes a plurality of segments which are urged into a circular arrangement by a circular coil spring 27, as explained in detail in my above referred to co-pending application. This latch 26 is merely for the purpose of removing the packer unit P from the well and the details thereof form no part of this invention.

After the lower packerunit P has been set in the well casing with the gripping slips 20 in engagement with the wall of the well casing, the bore of the packer P is open for the reception of the outer flow tube 10, which is then lowered into position within the packer unit P as the

tubing strings

14 and 15 are lowered into the casing. It is to be noted that during the setting of the lower well packer P and the insertion of the remainder of the dual packer of this invention into the casing, the well formations are killed, that is, held inactive or are prevented from flowing by weighted drilling mud which is disposed in the casing.

The flow tube 10 has a plurality of openings 30 at its lower end whereby fluid may pass from the area below the lower packer unit into the interior or bore of the tube 10. When the sealing elements 17 and 17a are expanded by the differential in well pressure acting thereagainst, the sealing elements seal off between the interior of the casing C and the exterior of the tubing 10. The tubing 10 has a radial external shoulder 31 which is adapted to engage an internal shoulder 25 within the bore of the packer P, just below the sealing element 17. When the shoulder 31 engages the internal shoulder 25, the Weight of the remainder of the dual packer and the pipe thereabove is imposed upon the lower packer P to maintain same in its set position in sealing and gripping contact with the well casing.

As best seen in Figures 4C and 4D, the flow tube 10 extends upwardly from the portion within the lower packer unit and has connection with an inlet ring 32 thereabove. The upper end of the inlet ring 32 is connected with a sleeve 33 which has its upper end connected to the lower end of the resilient annular packing element 34 of the upper packing unit E and also has a connection with a sleeve 35 through a shear pin or pins 36. The sleeve 35 is disposed within the annular sealing element 34 and serves to prevent the collapse of such sealing element 34 inwardly. The upper end of the sleeve 35 is connected to a slip carrying annular member 37 which has its upper end connected to the periphery of the lower end of the coupling member 11. It can thus be seen that the inlet ring 32, the sleeve 33, the sleeve 35 and the annular member 37 form a continuation of the flow tube 10 for connection with the coupling member 11 with the sleeve 35 and member 37 being detachable from the portion of the tube therebelow upon a shearing of pin 36, as will be explained.

The inner flow tube 12 is disposed within such continuation of the outer flow tube 10 and a resilient annular seal 38 is provided on the interior of the inlet ring 32 in contact with the exterior of the lower end of the inner tube 12 to thereby provide a fluid seal at the lower end of the annular space 16, such seal being maintained even during longitudinal movement of the inner tube 12 relative to the outer tube 10. The inlet ring 32 has a plurality of upwardly inclined openings 32a extending through the wall thereof above the seal 38, whereby when the packing element 34 is set, fluid may flow through such openings from the upper formation B into the annular space 16. Equalization ports. 39 are provided in the sleeve 35 above the packing element 34 to equalize the Well pressure above and below the element 34 prior to the time that such packing element is set to thereby prevent premature setting of same.

The packing element 34 is securely connected to the upper end of the sleeve 33 by a connector ring 40 and bolts 41. A rigid ring 42 is connected to the upper end of the sealing element 34 by bolts 43; such ring 42 and the sealing element 34 are entirely free from any connection with the sleeve 35, although the shear pin 36 maintains the sleeve 35 fixed relative to the sealing element 34 prior to the time the pin 36 is severed.

The slip carrying member 37 is threaded to the sleeve 35 thereabove and has mounted therewith a plurality of piston slip members 47, each of which is disposed in a radial opening 48 in the wall of the member 47 with seal rings 49 being provided between the exterior of each piston gripping slip 47 and the wall of the opening 48. A retaining plate 50 is bolted to the member 37 by bolts 51 in order to confine a spring 52 within a recess 53 in each of the members 47. The spring 52 thus serves to maintain the gripping members 47 in a retracted position. However, when a fluid force is exerted on the inner surface 47a of each of the pistons 47, they are moved radially outwardly so that the teeth 47b are forced into gripping engagement with the well casing C. The member 37 is adapted to move downwardly upon a shearing of the shear pin 36 so that the lower end 37a contacts the upper retainer ring 42 on the expander seal member 34, whereby the sealing member 34 is expanded into sealing engagement with the wall casing. When such sealing occurs with the sealing member 34, and fluid from the upper formation passes into the annular space 16, the fluid pressure in the annular space acts upon the rear or inward surface 47a of each of the piston gripping members 47 to urge them outwardly into gripping contact with the wall casing, to thereby hold the sealing element 34 in its set or sealing position.

As best seen in Figures 48 and 4C, thc coupling member 11 has two substantially parallel

vertical flow passages

45 and 46 which extend entirely through the coupling member 11. The upper end of the inner flow tube 12 is connected by threads or other means to the flow passage 46, so that fluid flow from the interior of the inner tube 12 passes into the flow passage 46. The lower end of the flow passage 45 is open and communicates with the annular space 16 by reason of the connection of the member 37 to the periphery of the lower end of the member 11, so. that fluid flowing from the annular space 16 can pass into such flow passage 45. The flow passage 45 is therefore in fluid communication with the upper formation while the flow passage 46 is in fluid communication with the lower formation.

Referring now to Figure 4B, therein it can bc seen that the

flow passages

45 and 46 are in fluid communication by reason of a lateral port 55 extending through the wall 56 separating

such flow pasasges

45 and 46. In the flow passage 46, above the lateral port 55, there is provided an annular recess 46a for anchoring a plug 57 therein for the control of the flow through the port 55. The plus 57 illustrated in Figure 4B is of a conventional construction and includes a central member 58 which has a longitudinal bore or opening 59 therethrough which communicates with a lateral opening 60 near the lower end thereof. Loosely suspended dogs 61 surround the central member 58 and an annular support ring 62 is provided thereabove with an annular flange 63. The central member 58 has an expansion cone 64 on its exterior surface which co-acts with the anchoring dogs 61, while at the upper end of the central member 58 a radial flange member 65 is provided. The method of inserting the plug 57 into and removing the plug 57 from, the flow passage 46 will be explained here inafter, but as can be seen in Figure B, the plug 57 ispositioned for use in the passage 4650 that the lateral opening 60 in the plug is aligned with the lateral port v of plug 57 is eliminated.

55in the coupling member 11 to thereby close the flow passage 46 below the plug 57 and to direct the flow from the flow passage 45 into the flow passage 46 above the plug 57.

The upper end of the coupling member 11 has one tubing string 14 threaded or otherwise connected to the flow passage 45 and a second tubing string 15 threaded or otherwise connected to the flow passage 46. These tubing strings are clamped together with any suitable means such as the U-shaped clamp 67, which has a connecting bolt 68 extending between the

tubings

14 and 15 to a similar clamping plate on the opposite side (not shown). The tubing string 15 preferably carries a gas lift valve 68 on the exterior thereof within the casing annulus, such valve 68 being of any conventional construction for assisting in the lifting of the oil from the formation in communication with the tubing string 15.

The tubing strings 14 and 15 diverge somewhat at their upper ends from their otherwise parallel relationship and pass through a casing head 70 of conventional construction and are connected into a tubing head 71 thereabove. The tubing head 71 includes a body 72 which has a pair

ofvertical passages

73 and 74 extending therethrough, with the passage 73 communicating with a lateral passage 75 and the passage 74 communicating with a lateral passage 76. At the upper end of the

passages

73 and 74 there can be connected extensions 14a and 1511, respectively, with suitable valves being associatedwith the tubing head for controlling flow through the

extensions

14a and 15a and the

lateral passages

75 and 76. The upper end of the tubing string 15 is threadedly connected to the lower end of the vertical passage 74 of the tubing head 71, while the upper end of the tubing string 14 is disposed in the passage 73 in engagement with slidabl'e latching slips 78 positioned within the passage 73. These latching slips 78 are adapted to slide upwardly to permit'the insertion of the upper end of the tubing string 14 but prevent downward movement of such tubing string 14 after it has been inserted by reason of a wedging action with an annular wedge member '79 disposed below the slips 78.. Suitable seals 80 may be provided above the latching member 78 to prevent leakage around the exterior of the tubing string 14.

In Figure 5, a portion of the coupling member 11 is illustrated with a straight hole plug 57" disposed in the flow passage 46. The straight hole plug 57' is identical with the side door plug 57 illustrated in Figure 4B, except that the vertical or longitudinal opening 59 extends entirely through the center member 58' instead of having its end closed and also the lateral port 60 The latching dogs 61', expander cone 64, annular support ring 62, shoulder 63 and the upper flange 65 are identical with the corresponding parts of the side door plug 57 illustrated in Figure 4B. As can be seen, the straight hole plug 57' closes oil the lateral port 55 so that production of oil, or operations in connection with the upper and lower formations are entirely separated.

In the operation or use of the dual production well packer of this invention, the lower packer unit P is first lowered into the casing C on a wire line running-in too-l (not shown) to aposition between the lower formation A and the upper formation B. It should be pointed out that when the packer unit P is lowered into the well casing, the well is killed, that is, is prevented from flowing by weighted mud in the casing. As explained in my above referred to co-pending application, the lower packer unit P is set in gripping contact and sealing engagement with the well casing upon a raising of the running-in tool relative to the packer unit P. The .friction springs 22 on the slip carrier 21 frictionally engage the well casing C to hold the lower packer unit P during the upward movement of'the running-in tool,

whereby the differential 'in well pressure acting above and below-the well packer unit P efiects a movement of the sealing cups 17 and 17a toward each other to move the slip expander members 19 and 19a toward each other for radially moving the gripping slips 20 into gripping contact with the well casing. Thereafter the running-in tool is removed from the casing, leaving the bore of the lower packer unit P open. The remainder of the dual production packer of this invention is then inserted into the well casing with the flow tube 10 being lowered into the open bore of the lower well packer unit P. As the well packer is lowered relative to the packer unit P, the flow tube 10 passes downwardly into the lower packer unit? and the weight of the dual packer is imposed upon the lower packer unit P when the annular shoulder 31 engages the internal projection 25 of the lower packer unit. Thus, the Weight of the packer above the lower packer unit serves to assist in maintaining the lower packer unit in gripping and sealing engagement with the well casing. It should be noted that during the lowering of the packer unit P and the remainder of the dual packer of this invention into the well casing, the tubing head 71 is not in position on the casing head 70 so that as thepacker is lowered additional sections of tubing can be added to the tubing strings 14 and 15.

After the shoulder 31 has contacted the inner projection 25 and the weight is imposed on the lower packer unit to hold the tube 10 against downward movement, then the upper packer unit E is set in sealing engagement with the well casing. This is accomplished by lowering the tubing strings 14 and 15 and imposing the weight thereof on the annular sleeve 35 to shear the shear pin or pins 36, whereby the annular sleeve 35 moves downwardly relative to the packing element 34, which is maintained in a fixed position since it is connected to the flow tube 10 which is held against downward movement. After the shear bolt 36 is severed, and downward movement of the tubing and the sleeve 35 is continued, the lower end 37a of the slip carrier member 37 abuts against the upper ring 42 of the packing element 34 to apply weight thereto for radially expanding the sealing element 34 into sealing engagement with the well casing. Also, it will be evident that the equalizer openings 39 move below the sealing element 34 so that the equalizing flow or circulation which prevents premature setting of the sealing element 34 is thereby closed and any flow through the inlet ports 32a into the annular space 16 will continue on upwardly to the flow passage 45 in the coupling member 11. Since the inner tube 12 is connected to the member 37, it will also move downwardly relative to the tube 10 as the sleeve 35 is lowered.

With the lower packer unit P and the upper packer unit E set aganst the casing, the parts are in the position illustrated in Figure 1. The tubing head 71 is then added to the upper end of the tubing strings 14 and 15. The upper end of the tubing strings 15 is inserted prior to the insertion of the upper end of the tubing string 14. This is accomplished by positioning the upper end of the tubing string 15 sufficiently above the upper end of the tubing string 14 so that the tubing head 71 can be rotated to thread the tubing head 71 to the upper end of the tubing string 15 without interference from the tubing string 14. Since the tubing strings .14 and 15 extend for a very long distance in the well casing (usually hundreds of feet) it is possible to compress or slacken the pipe string 15 upon lowering the tubing head 71 until it rests upon the upper end of the casing head 70. At the same time that the tubing head 71 is lowered, the upper end of the tubing string 14 is passed upwardly into the passage 73 of the tubing head. The slidable latching jaws 78 permit the upward movement of the upper end of the tubing string 14 but prevent subsequent downward movement of such string 14 due to the wedging action of the latching dogs 78 against the wedges 7 79. The tubing head 71 is then bolted to the casing head 70 in the usual manner.

With the tubing head thus in position and the suitable valves associated therewith being properly regulated, the well is then washed in by circulating a washing fluid downwardly through the passage 74 and the tubing string 15 and thence through the lateral port 55 and then upwardly through the tubing string 14 to the surface of the well. This circulation of the washing fluid removes the heavy drilling mud from the tubing strings 14 and 15 and therefore removes the mud retaining force which has previously been holding the formations A and B against flow. Thus, by the washing in circulation in the tubing strings 14 and 15, production from the formations A and B is brought about. The formation A produces into the well casing below the well packer of this invention and flows in through the openings 3% in the lower end of the flow tube and thence upwardly through the flow tube 10 and into the bore of the inner tube 12 which carries the oil into the flow passage 46 of the coupling member, and then upwardly into the tubing string 15. The upper formation B is in communication with the inlet opening 32a so that the oil from the formation B flows through said openings 32a into the annular space 16 and thence upwardly into the flow passage 45 of the coupling member 11 for transmission to the tubing string 14. When the lateral port 55 is open, there will of course be some intermingling of the oil passing upwardly through the

flow passages

45 and 46 from the two formations.

However, under normal circumstances the production from the two formations will be separated by the use of a straight hole plug 57' (Figure 2). The use of the straight hole plug 57 permits the upper and lower formations to produce separately by closing off the lateral port 55 in the coupling member 11. If necessary or desirable, the gas lift valve 68 on the tubing string may be utilized to raise the oil in such tubing string by injecting gas under pressure through the casing head 70 into the annular space in the casing surrounding the tubing strings 14 and 15. This is possible since the casing annulus around the tubing strings is not utilized for conducting fluid to or from the well formations.

In some instances it may be desirable to close off the flow from the lower formations and to provide a gas lift for the oil flowing from the upper formation. This can be effected by utilization of the side door plug 57 (Figure 3).

Although the insertion and removal of the straight hole plug and side door plug is by conventional means,

following is the basic procedure in connection with the side door plug 57. The procedure would be identical for the straight hole plug 57. Referring to Figure 4B in connection with the setting and releasing of the side door plug 57, such plug 57 is lowered upon a wire line or similar device (not shown) having means for holding the flange 63 in abutment with the flange 65, so that the latching dogs 61 are suspended above the expander cone 64. The latching dogs 61 can then pivot inwardly so as to pass through the upper end of the flow passage 46. When the latching dogs 61 have passed below the annular recess 46a, the tool holding the flange 63 in engagement with the flange 65 is released so that well pressure acting from below the plug 57 will force the central member 58 upwardly to wedge the expander 64 inside of the latching dogs 61 to thereby lock the dogs 61 in the recess 46a as shown in Figure 4B. The plug 57 is released by a wire line tool or a similar device having means for forcing the flange 65 downwardly into engagement with the lower flange 63 whereupon the latching dogs 61 upon an upward movement of the plug 57 will move inwardly, since the expander cone 64 has moved below the dogs 61. The plug can thereby be readily removed and another plug such as the straight hole plug 57' may be inserted in an identical manner.

8 In some cases it may be desirable to insert a completely closed plug (not shown), which would have no passage therethrough in order to close the lateral port 55 and also to close the flow in the flow passage 46.

From the foregoing description, it is believed evident that a dual production packer has been provided in which separate tubes are provided for an upper and lower formation so that production or other operations can be conducted in connection with each of the formations separately and without the necessity of pulling the tubing strings. Also, since the casing annulus is not utilized in the dual production with this packer, a gas lift valve may be incorporated with one of the tubing strings to increase production from either of the formations.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in size, shape and materials, as well as in details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed is:

1. A dual production well apparatus adapted to be positioned in a well casing and comprising, a lower packer unit adapted to be set in sealing contact with the well casing and also adapted to be disposed between a lower well formation and an upper well formation, an upper packer unit adapted to be set in sealing contact with the well casing and also adapted to be disposed above the upper well formation, an outer flow tube extending through the packer units and in sealing engagement therewith whereby said packer units seal off the annular space between the well casing and said outer flow tube, an inner tube disposed within the outer tube and extending through the upper packer unit, said inner tube being spaced from the outer tube to form an annular space therebetween, sealing means between the inner tube and the outer tube for preventing flow from the bore of said inner tube into said annular space, said outer tube having an opening near its lower end below said sealing means and said packer units whereby fluid from the lower formation may pass upwardly into the outer tube and into the inner tube, said outer tube also having an opening above said sealing means and between said packer units to establish fluid communication between said upper formation and said annular space, and a coupling member comprising a tubular body coupled to said outer tube and having two substantially parallel flow passages therethrough, a pair of tubing strings connected to said tubular body, one of said flow passages establishing fluid communication between one of said tubing strings and the annular space between the inner tube and the outer tube, and the other of said flow passages establishing fluid communication between the other of said tubing strings and the interior of said inner tube.

2. A dual production well packer apparatus adapted to be lowered into a well casing for producing from an upper well formation and from a lower well formation and including, a tubular coupling member having connected to its upper end a pair of tubing strings which extend to the surface of the well, said coupling member having a pair of substantially parallel flow passages ex tending therethrough, each of said passages being in communication with one of the tubing strings, a first tubular conductor connected to said coupling and extending downwardly therefrom with its upper end in communication with one of the passages, the lower end of said first conductor communicating with one of the well formations, a second tubular conductor connected to the coupling and extending downwardly therefrom with its upper end in communication with the other of said passages, the lower end of said second tubular conductor being in communication with the other of said well formations, a lower packer unit surrounding one of the tubular conductors sealing off the annulus between the conductor and the well casing and located at an elevation between the upper and lower producing well formations, and an upper packer surrounding both tubular conductors sealing off the annulus between said conductors and the well casing and located at an elevation above the upper producing well formation.

3. A dual production well packer apparatus adapted to be lowered into awell casing for producing from an upper well formation and from a lower well formation and including, a tubular coupling member having connected to its upper end a pair of tubing strings which extend to the surface of the well, said coupling member rhaving a pair of substantially parallel flow passages extending therethrough, each of said passages being in communication with one of the tubing strings, a first tubular conductor connected to said coupling and extending downwardly therefrom with its upper end in communication with one of the passages, the lower end of said first conductor communicating with one of the well formations, a second tubular conductor connected to the coupling and extending downwardly therefrom with its upper end in communication with the other of said passages, the lower end of said second tubular conductor being in communication with the other of said well formations, a lower packer unit surrounding one of the tubular conductors sealing off the annulus between the conductor and the well casing and located at an elevation between the upper and lower producing well formations, an upper packer surrounding both tubular conductors sealing off the annulus between said conductors and the well casing and located at an elevation above the upper producing well formation and means in the tubular coupling member establishing communication between the parallel flow passages to establish communication between the bores of a flexible line, said plug member having means for closing the communication-establishing means when in position within said passage to shut off communication between the two tubing strings. v

5. A dual production apparatus as set forth in claim 3, together with a removable plug member lowerable into one of the flow passages of the coupling member by means of a flexible line, said plug member having means for closing the communication-establishing means when in position within said passage to shut off communication between the two tubing strings, said plug member having a bore extending entirely therethrough so that flow through the passage in which the member is disposed is not interrupted when said member is located therein.

6. A dual production apparatus as set forth in claim ,3, together with a removable plug member lowerable into one of the flow passages of the coupling member by means of a flexible line, said plug member having means for closingthe communication-establishing means when in position within said passage to shut off communication between the two tubing strings, said plug member being solid in cross-section whereby when in position in said passage it not only shutsoff communication between the tubing strings but also closes flow through the passage in which it is disposed.

7. A dual production apparatus as set forth in claim 3, together with a removable plug member lowerable into one of the flow passages of the coupling member by means of a flexible line and adapted to occupy a final position therein, said plug member having an angular passage therein which passage establishes communication between that passage of the coupling member which is not occupied by the plug member and the tubing string which ;is connected to the upper end of the passage in which the plug member is disposed.

8. A well production apparatus for producing from ,an upper producing formation and a lower producing formation and including, a pair of tubing strings extending downwardly within a well bore, one of said tubing strings having its lower portion communicating with the upper formation and the other tubing string having its :lower portion communicating with the lower formation, a well packer within the well bore sealing off the well bore around said other tubing string which has its lower portion communicating with the lower formation at an elevation between the upper and lower formations, whereby the flow from each formation is directed into its communicating tubing string, conduit means connected to said tubing strings and having fluid passages communieating with the tubing strings and a lateral port communicating said fluid passages at an elevation within the well bore above said well packer,,and a removable plug member lowerable into one of the tubing strings and having means insertable into the conduit means to close the lateral port therein and shut off communication betweensaid tubing strings.

9. A well production apparatus as set forth in claim 8, wherein the plug member is formed with an axial bore extending therethrough so that flow through the tubing string in which said plug member is mounted is not interrupted when the plug is in position therein,

10. A well production apparatus as set forth in claim 8, wherein the plug member is solid in cross section and not only shuts off communication between the tubing strings but also closes flow through that string in which said member is mounted.

11. A well production apparatus for producing from an upper producing formation and a lower producing formation and including, a pair of tubing strings extending downwardly within a well bore, one of said tubing strings having its lower portion communicating with the upper formation and the other tubing string having its lower portion communicating with the lower formation, a well packer within the well bore sealing off at an elevation between the upper and lower formations, the well bore around said other tubing which has its lower portion communicating with the lower formation, whereby the flow from each formation is directed into its communicating tubing string, conduit means connected to said tubing strings and having fluid passages communicating with the tubing strings at an elevation within the well bore above said well packer, and a plug member lowerable into one of the tubing strings into a position adjacent the passage means, which establishes communication between the tubing strings, said member having a flow passage which establishes communication between that tubing string in which the plug member is not disposed and the portion of the tubing string in which the plug member -is disposed above the plug member.

12. A dual production well apparatus adapted to be positioned in awell casing and comprising, a lower pack- :er unit adapted to be set in sealing contact with the well casing and also adapted to be disposed between a lower well formation and an upper Well formation, an upper packer unit adapted to be set in sealing contact with the well casing and also adapted to be disposed above the upper well formation, an outer flow tube extending through the packer units and in sealing engagement therewith whereby said packer units seal off the annular space between the well casing and the said outer flow tube, an

inner tube disposed within the outer tube and extending through the upper packer unit, said inner tube being spaced from the outer tube to form an annular space therebetween, sealing means between the inner tube and the outer tube for preventing flow from the bore of said inner tube into said annular space, said outer tube having an opening near its lower end below said sealing means and the packer units whereby fluid from the lower formation may pass upwardly into the outer tube and into the inner tube, said outer tube also having an opening above said sealing means and between said packer units to establish fluid communication between said upper formation and said annular space, and a coupling member coupled to said outer tube comprising a tubular body having two substantially parallel flow pasages therethrough, a pair of tubing strings connected to said tubular body, one of said flow passages establishing fluid communication between one of said tubing strings and the annular space between the inner tube and the outer tube, and the other of said flow passages establishing fluid communication between the other of said tubing strings and the interior of said inner tube, and means establishing fluid communication between said flow passages in the coupling member whereby the well may be washed in to obtain production from the formations by a circulation of a washing fluid from one of said flow passages into the other of said flow passages.

13. A dual production well apparatus adapted to be positioned in a well casing and comprising, a lower packer unit adapted to be set in sealing contact with the well casing and also adapted to be disposed between a lower well formation and an upper well formation, an upper packer unit adapted to be set in sealing contact with the well casing and also adapted to be disposed above the upper well formation, an outer flow tube extending through the packer units and in sealing engagement therewith whereby said packer units seal oif the annular space between the well casing and the said outer flow tube, an inner tube disposed within the outer tube and extending through the upper packer unit, said inner tube being spaced from the outer tube to form an annular space therebetween, sealing means between the inner tube and the outer tube for preventing flow from the bore of said inner tube into said annular space, said outer tube having an opening near its lower end below said sealing means whereby fluid from the lower formation may pass upwardly into the outer tube and into the inner tube, said outer tube also having an opening above said sealing means to establish fluid communication between said upper formation and said annular space, and a coupling member coupled to said outer tube comprising a tubular body having two substantially parallel flow passages therethrough, a pair of tubing strings connected to said tubular body, one of said flow passages establishing fluid communication between one of said tubing strings and the annular space between the inner tube and the outer tube, and the other of said flow passages establishing fluid communication between the other of said tubing strings and the interior of said inner tube, said lower packer unit having annular sealing elements and slips which are set in sealing and gripping contact, respectively, with the well casing by a differential in well pressure above and below the packer unit, means on the outer tube for assisting in maintaining said lower packer unit in its set position in sealing and gripping engagement with the casing, said outer tube having an upper portion and a lower portion thereof which are longitudinally movable with respect to each other, said upper packer unit including an annular sealing element mounted on said lower portion of the outer tube and means on said upper portion of the outer tube to eflfect a compression and lateral distortion of the upper packer unit into sealing engagement with the well casing upon a longitudinal movement of said upper portion relative to said lower portion of said outer tube.

.14. A dual production well apparatus adapted to be positioned in a well casing and comprising, a lower packer unit adapted to be set in sealing contact with the well casing and also adapted to be disposed between a lower well formation and an upper well formation, an upper packer unit adapted to be set in sealing contact with the well casing and also adapted to be disposed above the upper well formation, an outer flow tube extending through the packer units and in sealing engagement therewith whereby said packer units seal off the annular space between the well casing and the said outer flow tube, an inner tube disposed within the outer tube and extending through the upper packer unit, said inner tube being spaced from the outer tube to form an annular space therebetween, sealing means between the inner tube and the outer tube for preventing flow from the bore of said inner tube into said annular space, said outer tube having an opening near its lower end below said sealing means and said packer units whereby fluid from the lower formation may pass upwardly into the outer tube and into the inner tube, said outer tube also having an opening above said sealing means and between said packer units to establish fluid communication between said upper formation and said annular space, and a coupling member coupled to said outer tube comprising a tubular body having two substantially parallel flow passages therethrough, a pair of tubing strings connected to said tubular body, one of said flow passages establishing fluid communication between one of said tubing strings and the annular space between the inner tube and the outer tube, and the other of said flow passages establishing fluid communication between the other of said tubing strings and the interior of said inner tube, said outer tube comprising telescoping upper and lower tube portions, said upper packer unit including an annular sealing element having connection at its lower end with the upper end of said lower tube portion of the outer tube, the upper end of the sealing element being free tomove downwardly relative to the upper end of the lower portion of the outer tube for expansion of the sealing element into sealing engagement with the well casing, said upper tube portion extending Within said sealing element and said lower tube portion and means on said upper tube portion for setting the sealing element upon a downward movement of said upper tube portion relative to said lower tube portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,335,355 Penick et al. Nov. 30, 1943 2,368,428 Saurenman Jan. 30, 1945 2,488,931 Penick Nov. 22, 1949 2,531,258 Cranfill Nov. 21, 1950