US3601196A

US3601196A - Remote perforating in dual completion wells

Info

Publication number: US3601196A
Application number: US837248A
Authority: US
Inventors: Thomas W Childers; Carl E Reistle
Original assignee: Exxon Production Research Co
Current assignee: ExxonMobil Upstream Research Co
Priority date: 1969-06-27
Filing date: 1969-06-27
Publication date: 1971-08-24
Anticipated expiration: 1988-08-24

Abstract

Method for perforating in a dual, parallel pipe string tubingless well. A crossover passage or port connects these pipe strings. Each pipe string is provided with a landing nipple at about the same depth below the crossover port. A radioactive source tool, which includes a radioactive pill for transmitting radiation in angular directions and a seating member for seating the radioactive source tool in the landing nipple arranged in one of the pipe strings, is pumped through the one pipe string until the seating member is landed in the landing nipple. The radioactive pill is suspended from the seating member a predetermined distance which is approximately the level at which it is desired to perforate. A perforating assembly, which includes a directional perforating gun, a directional radiation detector, a radioactivity-sensitive gun-firing mechanism including a source of electrical power for causing actuation of the perforating gun, a rotation device for causing the perforating gun to rotate, a seating member for seating the perforating assembly in the landing nipple arranged in the other pipe string, and a locomotive device for moving the perforating assembly through the other pipe string, is then pumped through the other pipe string until the seating member lands in the landing nipple. The detector of the perforating assembly is suspended a predetermined distance from the seating member so that it is positioned at the same level as the radioactive pill in the adjacent pipe string. The firing mechanism utilizes a switch which is actuated when the radioactive count detected by the radiation detector reaches a predetermined level. The directional gun is aimed so as to fire in a predetermined angular direction when the directional detector is facing the radioactive pill. The perforating assembly is rotated by circulating fluid in the pipe strings. After the perforating gun has fired, the perforating assembly is removed from the other pipe string. The radioactive source tool is then removed from the one pipe string. The perforating gun may be reloaded and the perforating procedure repeated at a different level in the well bore after repositioning the radioactive source tool and perforating assembly.

Description

FIP -Oll Primary Examiner-David H. Brown Attorneys-Thomas B. McCulloch, Melvin F. Fincke, John S.

Schneider, Sylvester W. Brock,-.lr., Kurt S. Myers and Timothy L. Burgess nipple arranged in one of the pipe strings, is pumped through the one'pipe string until the seating member is landed in the landing nipple. The radioactive pill is suspended from the seating member a predetermined distance which is approximately [72] inventors MVLCIders lasAn eles; Carlhleitkllhmbothof, Cl. [21] AppLNo. 837,248 [22] Filed 27,1969 [45] Patented 24,1971 [73] Assignee Emol'rohetiaalcecehcoqny [5'4] REMOTEPERFORATINGIN DUAL COMPLETION WELIS IOChldDr-awhgib.

[52] USJ 166/297, 166/250, 166/55.1,l75l4.51 [51] H "K216431119 [50] FisldofSearei 166/297, 313, 250, 255, 55.1; 175/451.

[56] Releru'seesClterl UNITEDSTA'I'ESPA'I'EN'IS 3,032,107 5/1962 Rumble etal 175/451 3,097,693 7/1963 'l75/4.51X 3,208,533 9/1965 166/313X 3,294,163 12/1966 l75/4.51X 3,426,851 2/1969 Arendt l75/4.51X

the level at which it is desired to perforate. A perforating assembly, which includes a directional perforating gun, a directional radiation detector, a radioactivity-sensitive gunfiring mechanism including a source of electrical power for I causing actuation of the perforating gun, a rotation device for is then pumped through the other pipe string until the seating member lands in the landing nipple. The detector of the perforating assembly is suspended a predetermined distance from the seating member so that it is positioned at the same level as the radioactive pill in the adjacent pipe string. The firing mechanism utilizes a switch which is actuated when the radioactive count detected by the radiation detector reaches a predetermined level. The directional gun is aimed so as to fire in a predetermined angular direction when the directional detector is facing the radioactive pill. The perforating assembly is rotated by circulating fluid in the pipe strings. After the perforating gun has fired, the perforating assembly is removed from the other pipe string. The radioactive source tool is then removed from the one pipe string. The perforating gun maybe reloaded and the perforating procedure repeated at a different level in the well bore after repositioning the radioactive source tooland perforating assembly.

PATENTED M1824 IHH SHEET 1 [IF 3 G-2A. FIG-2B.

FIG.

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5 0 M: m 2 B 6 :IHI w 3 N INVLNIURS THOMAS W. CHILDERS, CARL E. REISTLE,]I[, i -6 ATTORNEY.

PATENTEU AUB24|971 3.601; 196

sum 2 OF 3 F' I G 2 D R fi k v m I 0 o l/ FIG.2C

THOMAS w. CHILDERS, CARL E. REISTLEJII, %/WZM u- ATTORNEY.

REMOTE PERFORATING IN DUAL COMPLETION WELLS BACKGROUND OF THE INVENTION The present invention concerns method and apparatus for completing parallel, dual-string tubingless oil and/or gas wells which have through fiowline (TFL) servicing capability. Tubingless TFL completions have application to underwater wells, highly deviated offshore wells drilled from platforms, deviated wells drilled from urban drill sites or deviated wells drilled from land'to adjacent underwater reservoirs. One of the problems in completing such wells is to orient properly a perforating gun in one of the pipe strings so as not to shoot in the adjacent parallel pipe string. The ability to perforate using pumpdown techniques facilitates completion of subsea wells, as well as future workovers. In such wells, it is possible to move the drilling rig off location several days earlier than would be the case if the drilling rig were required to perform well-completion operations.

SUMMARY OF THE INVENTION A method for perforating in a tubingless TFL well containing two spaced-apart parallel pipe strings comprising launching into one of said pipe strings a radioactive source; pumping said radioactive source through said one pipe string to adjacent a level therein at which it is desired to perforate; launching into said other pipe string a perforating tool provided with a perforating gun having a selected direction of perforation, a detector of radiation having a selected direction of radiation detection relative to said direction of perforation, means for rotating said perforating gun when the perforating tool is caused to move by hydraulic pressure, a locomotive device for causing the perforating tool to move through and in the other pipe string by hydraulic pressure, a radioactivity sensitive firing mechanism including a source of electrical power for actuating the perforating gun and a switch actuated when the radioactive count detected by the radiation detector reaches a predetermined level; pumping the perforating tool through the other pipe string until the radiation detector is at the level of the radioactive source; moving the perforating tool by circulation of fluid through said pipe strings to cause said perforating gun to rotate until at one horizontal angular position of said perforating gun the detected radiation reaches a preselected level to indicate that the direction of detection of radiation is toward said radioactivesource and said direction of perforation is in a preselected direction, the perforating gun automatically firing or actuating when in such position. After the perforating gun has fired, the perforating tool is first circulated out of the well and then the radioactive source is circulated out of the well.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-sectional view of the earths surface showing a subsea borehole having arranged in it two pipe strings, one of which contains a perforating tool assembly and the other one of which contains a radioactive source tool positioned in accordance with the teachings of the invention;

FIGS. 2A-2F illustrate stepwise the perforating procedure for use in tubingless TFL completed wells;

FIG. 3 is a partly sectional view illustrating one embodiment of a perforating tool assembly rotating device;

FIG. 4 is a partly sectional view illustrating another embodiment of a perforating tool assembly rotating device;

FIG. 5 is a partly sectional view of still another embodiment I FIG. 9 schematically illustrates the firing mechanism circuit in which an overtravel switch is included.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, there is shown a borehole 10 penetrating a subsurface oilor gas-productive formation 11. Two eccentric parallel spaced-

apart pipe strings

12 and 13 are arranged in borehole 10 and cemented therein by means of cement 14. Pipestrings l2 and 13 are connected together by crossover port 15. Pipe string 12 is provided with a landing nipple 16 below crossover port 15 and pipe string 13 is provided with a landing nipple 17 at about the same level. A radioactive or nuclear source tool 18 is located in pipe string 12. The components of this tool include a radioactive pill 19 suspended at a preselected depth from landing nipple 16 to near formation 11 on a line or small-diameter flexible tubing 20 attached to a locating lockdown mandrel 21 provided with a seating shoulder 22 for seating in landing nipple 16, a

packoff 23 for sealing off the space between the interior sursealing off the space between the interior surface of the landing nipple and the outer surface of mandrel 29, and retractable, shearable lugs 32 for locking mandrel 29 in landing nipple 17. Mandrel 29 also contains the rotating mechanism which in this instance is the embodiment shown in FIG. 3 and described later herein. Perforating tool assembly 26 also includes a battery case 33 which is suspended from mandrel 29 by means of aline or small-diameter line flexible tubing 34. Battery case 33 contains electrical power to actuate firing head 35 which in turn detonates fixed directional perforating gun elements 36. A nuclear or radioactive source (radiation) detector 37 is positioned between the electrical power in battery case 33 and electrical firing head 35. Tubing 34 and tubing 20 are cut to suitable lengths to locate radiation detector 37 and radioactive source pill 19 at the same depth level in the well. Radiation detector 37 has a shielded window 38 which allows the radiation detector mechanism only to investigate in effect the radioactive count in a small horizontal angular range when battery case 33, radiation detector 37, firing head 35 and directional perforating gun elements 36 are rotated in a circle by means of the rotating mechanism. The function of the radiation detector 37 is to investigate the level of radiation of the borehole as it is being rotated around in a circle; and when the radioactive count reaches a preset level, indicating that the radiation detector window is directly facing radioactive source pill 19, a switch makes electrical connection between battery case 33 and firing head 36, which in turn detonates directional perforating gun elements 36 which are shown facing directly away from pipe string 12. A swivel 39 connects locomotive device 27 to the other components of the tool.

Any desired radioactive substance may be employed as the radioactive pill, such as radon, radium bromide, radium chloride, uranium bromide, uranium tetrabromide, etc. These are naturally radioactive substances; however, other artificial radioactive substances also may be employed.

Radiation detector 37 may be any device capable of converting radiation energy transmitted from the radioactive source to electrical pulses and which transmits said electrical pulses only when the radiation detected by said detector reaches a specified predetermined level. Suitable for use is a Gieger-Mueller counter or an ionization chamber or a proportional counter, each modified to transmit electrical signals only when the predetermined radiation peak is reached.

The shielding material on the detector is formed of radiation absorbing or moderating substances, such as lead, tungsten, paraffin, boron, cadmium, etc., which substances are capable of absorbing or moderating the detected radiation.

One type of mechanism for rotating the perforating gun elements 36 is illustrated in FIG. 3. Referring to FIG. 3, there is shown a splined keyway 40 connected through mandrel 29 by means of shaft 41 and chuck 42 to flexible tubing 34. A coiled band spring 43 is connected to shaft 41. A splined shaft 44 is initially arranged in splined keyway 40. A support 45 is attached to splined shaft 44 and a compression spring 46 is attached at one end to the support and at the other end thereof to the upper interior end of mandrel 29 to inhibit upward movement of splined shaft 44. The upper end of splined shaft 44 is connected to locomotive device 27 through swivel 39. This rotating mechanism operates as follows. Mandrel 29 is set in landing nipple 17 and fluid is circulated down pipe string 12 through crossover port 15 and up pipe string 13. Swab cups 28 are forced upwardly which causes connected splined shaft 44 to move upwardly against the bias of spring 46 until splined shaft 44 is no longer engaged in splined keyway 40. Coiled band spring 43 then causes slow rotation of shaft 41 which in turn rotates tubing 34 and radiation detector 37 and gun elements 36 in one or more complete revolutions.

Another embodiment of the rotating mechanism, illustrated in FIG. 4, includes a splined keyway 50 connected to the rotatable components by means of shaft 51. A splined shaft 52 is keyed into splined keyway 50 and is initially prevented from vertical movement in the keyway by shear pin 53 which connects keyway 50 and shaft 52. A threaded shaft 54 connects shaft 52 to swivel 39 and locomotive device 27. Shaft 54 extends through a threaded headnut 55. In operation of this embodiment, fluid is circulated down pipe string 12. through bypass 15 and up pipe string 13 to force swab cups 28 upwardly. Movement of swab cups 28 upwardly moves shaft 54 upwardly through threaded headnut 55 to cause shear pin 53 to shear and permit shaft 52 to rotate keyway 50 and shaft 51 connected to keyway 50 through one or more revolutions.

The rotating mechanism shown in FIGS. and 6 is a racheting sawtooth arrangement. As seen in these figures, a rotatable shaft 60 extends through the lower end of mandrel 29 and connects to the rotatable gun elements. The upper end 65 of shaft 60 which is square shaped extends through a collar or sleeve 61 and is slidably arranged within a hollow squareshaped rod 66 attached to collar 61. Rod 66 extends through the upper end of mandrel 29 and connects to swivel 39. Collar 61 is provided with a cam follower 62 which engages in a sawtooth" or Y-shaped cam surface or track 63 formed in the inner wall of mandrel 29. As seen particularly in FIG. 6, track 63 is provided with hinged leaf springs 64 at each juncture of the vertical paths of track 63 to permit cam follower 62 to travel and shaft 60 operably attached thereto to rotate, in only one direction, as indicated by the arrow. In the operation of this embodiment, fluid is circulated down pipe string 12 through bypass and up pipe string 13 to move swab cups and shaft 66 and collar 61 and cam follower 62 upwardly until cam follower 62 travels up to the upper portion of track 63. Then by gravity or by reverse circulation of fluid down pipe string 13 through bypass 15 and up pipe string 12, swab cups and collar 61 and cam follower 62 move down and into the next succeeding leg of each Y section as indicated. As collar 61 is rotated by the travel of cam follower 62, rod 66 is rotated which in turn rotates shaft 65 and shaft 60 attached to shaft 65.

As shown in FIG. 7 a pressure switch 70 is connected into the detector-battery-gun circuit, generally designated 71, to ensure that the gun is only armed for firing at the depth at which it is to be used. Pressure switch 70 is preset for a selected hydraulic pressure in the pipe string.

Another safety precaution is shown in FIGS. 8 and 9. An overtravel switch 75 is provided with a rod contact 76 which engages support member 45 upon movement of that support member upwardly. It is designated to actuate just prior to separation of the splined keyway 40 and key shaft 44 described with reference to FIG. 3. Housing 29 may be filled with a nonconductive liquid when a slipring-type conductor is used. The circuit shown in FIG. 9 includes the pressure switch 70.

The perforating operation is illustrated in FIGS. 2A-2F. In FIG. 2A, radioactive or nuclear source tool 18 to which has been connected a running tool 80, having oppositely facing swab cups 81 and releasable prongs 82 connected to running and retrieving head 24 of nuclear source tool 18, is launched in pipe string 12 and pumped through that pipe string until mandrel 21 is landed in landing nipple 16 to position radioactive pill 19 at a predetermined level.

As shown in FIG. 2B, locomotive running tool 80 is retrieved by reverse circulating fluid down pipe string 13 through bypass 15 and up pipe string 12.

As shown in FIG. 2C, perforator tool 26 has been launched in pipe string 13 and pumped through that pipe string until mandrel 29 is landed in landing nipple 17 by circulating fluid down pipe string 13 through bypass 15 and up pipe string 12 as indicated. Radiation detector 37 is then located at a preselected depth at the same level as radioactive pill 19.

When it is desired to cause perforation of formation 11 fluid is pumped down pipe string 12 through bypass 15 and up pipe string 13 to move locomotive device 27 upwardly and cause radiation detector 37 to rotate in accordance with the operation described with respect to FIG. 3. Either of the other two techniques illustrated and described with respect to FIGS. 4 and 5 may also be used to cause rotation of detector 37. As illustrated in FIG. 2D, when detector window 38 is facing radioactive pill 19, electrical power is applied to firing head 35 to cause gun elements 36 to fire. As indicated by the simple circuits shown in FIGS. 7 and 9, sufficient pressure must exist to actuate pressure switch to complete the circuit (FIG. 7) and if the overtravel switch is used, then that switch must also be actuated to complete the circuit as illustrated in FIG.

As illustrated in FIG. 2E, perforator tool assembly 26 is circulated from pipe string 13 by pumping fluid down pipe string 12 through bypass 15 and up pipe string 13.

Nuclear source tool 18 is then retrieved by pumping a retrieving tool 85, having oppositely facing swab cups 86 and prongs 87 for latching onto retrieving head 24 of nuclear source tool 18, is pumped through pipe string 12 until it latches onto nuclear source tool 18. Then, as illustrated in FIG. 2F, fluid is pumped down pipe string 13 through bypass 15 and up pipe string 12 under sufficient pressure to cause shearable lugs 25 to shear to permit removal of nuclear source tool 18 from pipe string 12.

Having fully described the apparatus, advantages, objects and method of our invention, we claim:

1. A method for perforating in a tubingless TFL well containing two spaced apart, parallel pipe strings comprising:

launching a radioactive source into one of said pipe strings; pumping said radioactive source through said one pipe string to adjacent a level therein at which it is desired to perforate;

launching into said other pipe string a perforating tool provided with a perforating gun having a selected direction of perforation, a detector of radiation having a selected direction of radiation detection relative to said direction of perforation, means for rotating said perforating gun when said perforating tool is caused to move by hydraulic pressure, a locomotive device for causing said perforating tool to move through and in said other pipe string by hydraulic pressure, a radioactivity-sensitive firing mechanism including a source of electrical power for actuating said perforating gun, and a switch actuatable when the radioactive count detected by said radiation detector reaches a predetermined level;

pumping said perforating tool through said other pipe string until the radiation detector is at the level of said radiation pill; and

moving said perforating tool by circulation of fluid through said pipestrings to cause the perforating gun to rotate until at one angular position of said perforating gun the detected radiation by said radiation detector reaches a preselected level to indicate that the direction of detection of radiation is toward said radioactive pill and said direction of perforation is in a selected direction, said perforating gun automatically firing when in such position.

2. A method as recited in claim 1 in which said direction of perforation is away from said one pipe string.

3. A method as recited in claim 1 in which said direction of perforation is toward said one pipe string.

4. A method as recited in claim 1 in which said perforating gun automatically firing when in said one angular position when well pressure adjacent said perforating tool is at a predetermined level.

5. A method as recited in claim 4 in which movement of said perforating tool by circulation of fluid to cause the perforating gun to rotate also actuates a switch to permit said perforating gun to fire.

6. A method as recited in claim 1 including the step of reverse circulating said perforating gun out of said other pipe string after firing of said perforating gun.

7. A method as recited in claim 6 wherein said perforating tool is moved upwardly to cause said perforating gun to rotate.

8. A method as recited in claim 6 including moving said perforating tool upwardly and downwardly to cause said perforating gun to rotate.

9. Apparatus for perforating in a tubingless TFL well containing two spaced apart, parallel pipe strings connected together through a crossover port comprising:

a pumpable perforating tool adapted to be pumped into and out of one of said pipe strings and provided with a perforating gun having a selected angular direction of perforation and a detector having a selected angular direction of radiation detection relative to said direction of perforation, locomotive means for causing said perforating tool to move vertically in one of said pipe strings when acted upon by hydraulic pressure, rotating means

Claims

1. A method for perforating in a tubingless TFL well containing two spaced apart, parallel pipe strings comprising: launching a radioactive source into one of said pipe strings; pumping said radioactive source through said one pipe string to adjacent a level therein at which it is desired to perforate; launching into said other pipe string a perforating tool provided with a perforating gun having a selected direction of perforation, a detector of radiation having a selected direction of radiation detection relative to said direction of perforation, means for rotating said perforating gun when said perforating tool is caused to move by hydraulic pressure, a locomotive device for causing said perforating tool to move through and in said other pipe string by hydraulic pressure, a radioactivity-sensitive firing mechanism including a source of electrical power for actuating said perforating gun, and a switch actuatable when the radioactive count detected by said radiation detector reaches a predetermined level; pumping said perforating tool through said other pipe string until the radiation detector is at the level of said radiation pill; and moving said perforating tool by circulation of fluid through said pipe strings to cause the perforating gun to rotate until at one angular position of said perforating gun the detected radiation by said radiation detector reaches a preselected level to indicate that the direction of detection of radiation is toward said radioactive pill and said direction of perforation is in a selected direction, said perforating gun automatically firing when in such position.

9. Apparatus for perforating in a tubingless TFL well containing two spaced apart, parallel pipe strings connected together through a crossover port comprising: a pumpable perforating tool adapted to be pumped into and out of one of said pipe strings and provided with a perforating gun having a selected angular direction of perforation and a detector having a selected angular direction of radiation detection relative to said direction of perforation, locomotive means for causing said perforating tool to move vertically in one of said pipe strings when acted upon by hydraulic pressure, rotating means for rotating said perforating tool when said perforating tool is moved vertically in said one pipe string by hydraulic pressure, and means for automatically firing said perforating gun when the level of radiation detected is at a preselected value; and a radiation source adapted to be pumped into and out of said other pipe string.

10. Apparatus as recited in claim 9 including means arranged on said perforating tool adapted to prevent firing of said perforating gun until a predetermined pressure is reached in said one pipe string at the level of said perforating tool.