US3373816A - Method for injector tubing gas lift - Google Patents

Description

March 19, 1968 c. B. COCHRAN 3,373,816

METHOD FOR INJECTOR TUBING GAS LIFT Filed Oct. 1 1965 5 Sheets-Sheet 1 A 77' ORA/f 1K5 mums/6,4 004mm [NVElT R.

March 19,1968 c. B. COCHRAN I 3,373,816

METHOD FOR INJECTOR TUBING GAS LIFT Filed Oct. 11, 1965 5 Sheets-Sheet 2 Z%, 4 BY MK MAM A T TOR/V575 March 19, 1968 c. B. COCHRAN METHOD FOR INJECTOR TUBING GAS LIFT 5 Sheets-Sheet 3 Filed Oct. 11, 1965 INVENTOR.

CHUDLEIGHB. (Mel-IRAN ATTORNEYS March 19, 1968 c. B. COCHRAN 3,373,316

METHOD FOR INJECTOR TUBING GAS LIFT Filed 001. 11, 1965 5 Sheets-Sheet 1 ATTORNEYS c. B. COCHRAN 5 sheets-sheets CHUDLE/G'H B. aaaflkA/v (j INVENTOR. BY I M March 19, 1968 METHOD FOR INJECTOR TUBING GAS LIFT Filed 001. 11, 1965 Z a y 222 MZZZ J aw 7 7%. H w 5 1 A a W Z a a a .5 w x a a a United States Patent 3,373,816 METHOD FOR INJECTOR TUBING GAS LIFT Chudleigh B. Cochran, Houston, Tex., assignor to Cicero C. Brown, Houston, Tex. Filed Oct. 11, 1965, Ser. No. 494,686 4 Claims. (Cl. 166-46) ABSTRACT OF THE DISCLOSURE A method of installing gas lift valves and appurtenant tubing in a well. The invention includes a novel method of utilizing injector type tubing unwound from a spool or the like for attachment to and supporting one or more gas lift valves in a well.

This invention relates to methods and apparatus for installing gas lift valves in a well, and more particularly, to methods and apparatus for installing such gas lift valves in a well by using injector tubing.

The use of gas lift valves in the production of oil and other fluids is well known, for example see Lester Charles Uren, Petroleum Production Engineering, Chapter HI, pp. 158-214 (2nd Ed., McGraw-Hill Book Company, Inc.). Gas lift valves are conventionally interposed in jointed production tubing and may be utilized to produce a formation fluid either through the production tubing or through the annulus between the tubing and the casing.

During the installation of gas lift valves by conventional methods and with conventional equipment, it is necessary to make up joints of tubing with gas lift valves interposed at desired intervals. Since many wells are quite deep, 21 great deal of time is consumed in making up the joints of tubing and interposing the valves. If valves are to be serviced after installation, it becomes necessary to either withdraw the tubing from the well with work-over equipment or to use a wire line rig and run the risk of breaking the small diameter wire in the well and having to fish out the lost portion. The workover equipment needed to effect installation and withdrawal is necessarily bulky and expensive, and the time requirements compound the expense.

.Recently, an apparatus for injecting a continuous length of tubing into a well has been devised to render less time consuming and expensive the servicing of a well. Such an apparatus is taught by US. Patent No. 3,116,781 issued Jan. 7, 1964 and entitled Apparatus for Completion and Working Over of Wells.

Accordingly, it is an object of this invention to provide novel methods and apparatus for installing gas lift valves into a well without the necessity of making up a plurality of joints of conventional tubing.

Another object is to provide methods and apparatus for installing gas lift valves in a well which do not require the use of expensive conventional work-over equipment.

Yet another object is to provide a faster method of completing a well for gas lift operations, and once completed, for pulling and services the valves.

, Still another object is to provide methods and apparatus for completing a well for gas lift without complete disassembly of well head equipment such as a Christmas tree.

An additional object is to provide apparatus permitting the attachment of gas lift valves to a continuous length of tubing. 4

The inventive method may-be generally described as a method of installing gas lift valves and appurtenant tubing in a well which includes the steps of inserting through a well head a length of substantially inflexible tubing which is fed into the well from a reel of tubing proximate the well head; attaching a body to the tubing which carries a gas left valve adapted to communicate with the tubing; and feeding an additional length of tubing into the well to position the gas lift valve at the desired depth.

Typical apparatus of the invention may be described as a clamp having pivotally mounted tubing encompassing members which permit the clamp to be opened, placed about the tubing and closed thereabout. Means are carried by the clamp for securely fixing the clamp about the tubing and means are also provided for mounting a gas lift valve on the clamp to permit communication between the gas lift valve and the tubing.

To be more specific, reference is now made to the drawings in which:

FIG. 1 is a cross-sectional view of a well with injector tubing inserted therein.

FIG. 2 is a cross-sectional view similar to FIG. 1 showing a severed length of injector tubing which has been suspended in the well to permit attachment of a gas lift valve by interposition.

FIG. 3 is a cross-sectional view similar to FIG. 2 which illustrates injector tubing containing a plurality of interposed gas lift valves.

FIG. 4 is a cross-sectional view similar to FIG. 3, but additionally illustrating the connection of the tubing to a gas source and the packing elements which seal the tubing within the well.

FIG. 5 is a partial cross-sectional view of a mandrel which is adapted to be interposed in a length of injector tubing.

FIG. 6 is a cross-sectional view along line 6-6 of FIG. 5.

FIG. 7 is a view in elevation of one embodiment of an apparatus which permits connection of a gas left valve to a continuous length of tubing.

FIG. 8 is an elevational view of the FIG. 7 embodiment rotated "v clockwise relative to a plan view of FIG. 7.

FIG. 9 is a cross-sectional view along line 99 of FIG. 8.

FIG. 10 is a cross-sectional view along line 101il of FIG. 9.

FIG. 11 is a cross-sectional view of a well illustrating a plurality of the apparatus illustrated in FIGS. 7-10 which have been attached to a length of injector tubing.

FIG. 12 is a partially cutaway view in elevation of an alternative embodiment of the invention which in many respects resembles the embodiment illustrated by FIGS. 710

Referring now to FIG. 1, in particular, a well is generally provided with surface structure such as a well head 1 which is mounted on casing 2 and from which depends production tubing 3. A plurality of suitably valved fiow lines 4 may communicate with the tubing and typically the annulus between the casing 2 and tubing 3 can be communicated with external surface equipment through suitably valved conduits 5. The annulus between the casing 2 and tubing 3 is typically packed off by a packer 6 so that any fluids entering casing 2 through perforations 7 therein may be produced through production tubing 3. The perforations 7, of course, communicate with the producing formation 8.

When the producing formation 8 discontinues production under natural energy it becomes necessary to apply external energy and it is with one such method of applying such energy that this invention is concerned. That method of supplying external energy is, as has been mentioned, the use of gas lift valves. To feed tubing and the gas lift valves to be attached thereto into the well, an apparatus 9 such as taught in US. Patent No. 3,116,781 issued Jan. 7, 1964 and entitled Apparatus for Completion and Working Over Wells is positioned proximate the well head 1. Apparatus 9 includes means (not illustrated) for driving drum 11 so that the injector tubing 12 carried about the drum is fed into well head 1, as illustrated in FIG. 1.

The end of injector tubing 12 is closed by any suitable method and when a desired length of tubing 12 has been inserted into tubing 3, as illustrated in FIG. 2, slips 13 are seated against frusto-conical shoulder 14 for grippingly supporting the injector tubing 12. Tubing 12 is severed thereby forming ends 15 and 16 between which is interposed a mandrel 17 equipped with a conventional gas lift valve 18. The detail of conduit 17 with attached gas lift valve 18 is better illustrated in FIG. 5, to which reference is here made.

In FIG. 5, the mandrel 17 includes a conduit 19 which at both ends is provided with identical structure, and for convenience, like parts at each end will be given the same reference numerals and the structure at only one end will be described. The upper end of conduit 19 has secured thereto by any conventional means an externally threaded collar 21. Collar 21 defines a cylindrical recess 22 which has a greater internal diameter than the outer diameter of tubing 12 to which conduit 19 is aflixed. Recess 22 receives an annular sleeve 23 which is provided with a radially extending flanged portion 24, which abuts the corresponding shoulder 25 of collar 21. Sleeve 23 and collar 21 define therebetween an annular space within which end 16 of tubing 12 is received. Disposed about tubing 12 is an O-ring type seal 26 above which is carried an annular washer 27.

Also placed and spaced about tubing 12 are a plurality of slips 28, as particularly illustrated in FIG. 6, which have oblique outer surfaces 29 that taper radially inward toward the tubing 12 oriented end of the collar 21 as illustrated. Carried about slips 28 is an annular slip ring 31 provided with a mating oblique surface 32 which also tapers radially inwardly toward the tubing 12 oriented end of collar 21. To permit slip ring 31 to be forced downward to drive slips 28 into engagement with end 16 of tubing 12 and thereby fixedly secure end 16 between slips 28 and sleeve 23, tubing 12 loosely carries an annular connector 33 provided with threads adapted to mate with the threads on collar 21. Connector 33 has a recess 35 which terminates in a shoulder 34. As collar 21 is threadably engaged with connector 33, by relative rotation, the slips 28 will be driven into engagement with end 16 of tubing 12. Sleeve 23 serves as a supporting element to prevent collapse of end 16 as slips 28 move radially inward. While tubing 12 is substantially inflexible, it nevertheless is flexible to a degree to permit feeding from 11 and could collapse radially inward if too great a pressure was applied.

As slips 28 move radially inward they will move downward to some extent causing Washer 27 to deform O-ring type seal 26 to insure an adequate fluid seal between conduit 19 and tubing 12.

Conduit 19 intermediate its ends carries a lug 36 and brackets 37 and 38 which in a conventional manner support a conventional gas lift valve .18. Typical of valves which may be used are the Macco valves illustrated in the 1964-1965 Composite Catalog of Oil Field Equipment and Services, pp. 3032-3035. Valve 18 communicates with the interior of tubing 12 through a conventional recess 39, passageway 40 and aperture 41.

To attach mandrel 17 to tubing 12 by interposition, mandrel 17 is positioned between ends 15 and 16 which are inserted, at their respective ends of mandrel 17, between sleeves 23 and slips 31. The collars 21 and connectors 33 are threadably engaged as described above thus securely interposing the mandrel 17 and gas lift valve 1 8 in tubing 12.

Once mandrel 17 has been interposed in tubing 12, slips 13 may be removed from well head 1 and an additional length of tubing 12 fed into the well. Should it be necessary to interpose other mandrels 17, the slips 13 are again placed in well head 1 and another mandrel 17 with gas lift valve 18 is interposed as described above.

As particularly illustrated in FIG. 3, a plurality of the mandrels 17 may be interposed. Once the desired number of mandrels 17, at the desired spacing, have been interposed in tubing 3, slips 13 are set and packing elements'42 are sealingly set in well head 1 by threadable engagement of sleeve 43.

The tubing injector apparatus 9 is removed and tubing 12 is coupled to a source. of pressurized gas 44. Gas lift valves 18 then function in a'conventional fashion to aid production of formation fluid through the annulus between injector tubing 12 and production tubing 3.

Another embodiment of apparatus permitting attachment of a gas lift valve to the injector tubing 12 is illustrated in FIGS. 7-10.

The alternative apparatus illustrated in FIGS. 7-10 includes a clamp 45 having arcuate tubing encompassing members 46 and 47 which are pivotally mounted by a pin 48. Pin 48 passes through registering hinge portions 49 and 51 of members 46 and 47, respectively.

Members 46 and 47 are securely fixed to tubing 12 by means of allen screws 52 or the like which threadably engage member 46 moving the members 46 and 47 radially inward. Member 47 is provided with a scored surface 53, as particularly illustrated in FIGS. 9 and 10, for grippingly engaging tubing 12.

Clamp 45 is provided with an integral lug 54 and brackets 55 and 56 which retainingly receive a conventional lgas lift valve 57 such as the Macco valves referred to above. Lug 54 is provided with a recess 58 which through passageway 59 and aperture 61 in tubing 12 permit communication between the gas lift valve 57 and the interior of tubing 12. To assure a seal between the clamp 45 and tubing 12, member 46 carries an imbedded circular resilient seal 62 which has a concave face 63 to assure engagement with the exterior of tubing 12.

To attach the clamp 45 totubing 12, a portion of tubing 12 is run into the well head 1 as illustrated in FIG. 1, the end of tubing 12 being closed. An aperture 61 is drilled in tubing 12. at a desired spot and the members 46 and 47 are pivotally opened and placed about tubing 12. When passageway 59 has been registered with aperture 61, the members 46 and 47 are pivotally closed and fixedly secured to tubing 12 by threadable engagement of screws 52; An additional length of tubing 12 may be fed from drum 11, and when a desired length has been reeled from the drum, another aperture'may be drilled in tubing 12 and another clamp 45 attached.

FIG. 11 illustrates a length of tubing 12 to which a plurality of the clamps 45 have beenv attached.

Once a desired number of claimps 45 have been aflixed, as illustrated in FIG. 11, the Well head 1 is packed off as described before and tubing 12 is connected to a source of pressurized gas.

Another embodiment of the invention is illustrated in FIG. 12. In FIG. 12, two clamps 63 and 64 are provided. Clamp 63 includes arcuate tubing encompassing members 65 and 66 which are pivotally mounted by pin (not illustrated) in much the same manner as members 46 and 47 of the previously described embodiment. Clamp 63 through member 66 retains the top of gas lift valve 68, the bottom of which is carried by member 69 of clamp 64. Clamp 64, like clamp 63, comprises members 69 and 71 pivotally mounted by a pin (not illustrated).

Member 69 of clamp 64 retainingly receives the gas lift valve 68 and through the recess 74 and passageway 75 therein permits the gas lift valve 68 to communicate with the interior of tubing 12 through aperture 61.

The FIG. 12 embodiment is assembled on tubing 12 in m h the same a e as the embodiment illustrated in FIGS. 7l0, except clamp 63 is fixedly secured by screws 76 after passageway 75 has been registered with aperture 61 and clamp 64 has been secured to tubing 12 by similar engagement of its screws 76.

A plurality of the embodiments illustrated in FIG. 12 may be used in the same manner as was described in connection with the embodiment illustrated in FIGS. 7-10. The well head 1 is packed off in the previously described manner and tubing 12 communicated with a gas source.

While the embodiments illustrated in FIGS. 7-10 and 12 utilize a hinge as a means for mounting the tubing encompassing members, various other means may be employed. For example, the two members may be joined by a dovetail type connection or any other suitable mechanical expedient.

Because in a typical well the spacing between gas lift valves may be 700 feet, it is less time consuming and more economical to feed substantial lengths of continuous tubing into the well and apply gas lift valves as desired than to make up conventional joints of tubing between which are interposed mandrels carrying gas lift valves.

By use of the apparatus of the present invention gas lift valves may be attached rapidly and at desired intervals. With the preferred embodiment of the invention, it

is not even necessary to sever the tubing to attach a gas lift valve. As will be obvious from the above, the inventive method and apparatus may be used to produce through tubing 12 rather than through the annulus between tubings 12 and 13.

While rather specific terms have been used to describe several embodiments of the methods and apparatus of the present invention, they are not intended nor should they be construed as a limitation on the invention as defined by the claims.

What is claimed is:

1. A method of installing gas lift valves and appurtenant tubing in a well comprising the steps of:

inserting through a well head a length of substantially inflexible tubing which is fed into the well from a reel of the tubing positioned proximate the well head;

severing the length of tubing;

interposing between the ends of tubing formed by the severing a mandrel provided with a gas lift valve; inserting the mandrel and valve into the Well by feeding an additional length of tubing from the drum; and severing the length of tubing at a point above the first mandrel and interposing between the ends thus formed another mandrel provided with a gas lift 6 valve and continuing to insert tubing, sever and interpose mandrels until a desired length of tubing provided with a desired number of mandrels has been positioned in the well. 2. A method of installing a gas lift valve and appurtenant tubing in a well, comprising the steps of:

inserting through a well head a length of substantially inflexible tubing which is fed into the well from a reel of tubing positioned proximate the well head; attaching to the tubing at least one body equipped with a gas lift valve which communicates with the interior of the tubing; and feeding an additional length of tubing from the reel to position the gas lift valve within the well. 3. A method of installing a gas lift valve and appurtenant tubing into a well comprising the steps of:

inserting through the well head a length of continuous substantially inflexible tubing which is fed into the well from a reel of the tubing positioned proximate the well head; drilling an aperture in a portion of the tubing exposed above the well head; and securing about the tubing a clamp upon which is mounted a gas lift valve adapted to communicate with the tubing through the aperture drilled therein; continuing insertion of the tubing into the well to position the gas lift valve within the well. 4. The method of claim 3 containing the additional steps of:

drilling at least one additional aperture in the tubing above the first mentioned aperture; clam-ping about the tubing another body upon which is mounted a gas lift valve; and continuing to insert the tubing into the well to position the gas lift valve within the well.

References Cited UNITED STATES PATENTS 2,548,616 4/1951 Priestman et al. -203 X 3,116,793 1/1964 McStravick 16646 X 3,313,346 4/1967 Cross 166-77 X FOREIGN PATENTS 621,470 6/ 1961 Canada. 712,923 7 1965 Canada.

CHARLES E. OCONNELL, Primary Examiner.

DAVID H. BROWN, Examiner.

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