US3730282A

US3730282A - Mechanically oriented perforating system

Info

Publication number: US3730282A
Application number: US00123344A
Authority: US
Inventors: R Chapman
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1971-03-11
Filing date: 1971-03-11
Publication date: 1973-05-01
Anticipated expiration: 1990-05-01

Abstract

There is disclosed an apparatus for mechanically orienting a through-tubing perforating gun in a multiple completion wall for perforating an upper formation without damage to other tubing strings in the well. The apparatus comprises an inclined plane in the tubing string and an inclined plane on the perforating gun to rotate the perforating gun about the long axis thereof. The gun carried orienting plane is positioned below the perforating elements and an end of tubing locator is positioned adjacent the bottom of the orienting plane. Suitable electrical controls are provided to prevent firing of the perforating gun until the orienting surfaces are parallel and until the end of tubing locator sensibly engages the bottom of the tubing.

Description

United States Patent 1 Chapman MECHANICALLY ORIENTED PERFORATING SYSTEM [75] Inventor: Ronald W. Chapman, Metairie, La. [73] Assignee: Shell Oil Company, New York, NY. 22 Filed: Mar. 11, 1971 211 AppL No; 125,344

1521 us. 121...; ..17s/4.s1, 166/297 511 Int. Cl. ..E2lb 43/119 [58] Field of Search ..175/4.5l, 4.56, 45,

[56] References Cited UNITED STATES PATENTS 3,130,784 4/1964 Pennington 166/297 X 3,031,965 5/1962 Nelson l 75/4.5l

1,330,954 6/1921 Hall et al. ....l66/255 X 3,011,550 12/1961 Kenneday .....l75/4.5l

3,070,166 12/1962 Knauth 166/243 X 3,104,710 I Pitts ..l75/4.5l

14 1 May 1, 1973 6/1969 Kinley et a1 ..l75/4.56 X

3,447,604 3,465,836 9/1969 Fields ..l75/4.51 3,550,695 12/1970 Shore ..l75/4.56 X

Primary Examiner-David H. Brown Attorney--H. W. Coryell and Harold L. Denkler [5 7] ABSTRACT There is disclosed an apparatus for mechanically orienting a through-tubing perforating gun in a multiple completion wall for perforating an upper formation without damage to other tubing strings in the well, The apparatus comprises an inclined plane in the tubing string and an inclined plane on the perforating gun to rotate the perforating gun about the long axis 7 thereof. The gun carried orienting plane is positioned below the perforating elements and an end of tubing locator is positioned adjacent the bottom of the orienting plane. Suitable electrical controls are provided to prevent firing of the perforating gun until the orienting surfaces are parallel and until the end of tubing locator sensibly engages the bottom of the tubing.

' 17 Claims, 8 Drawing Figures Patented May 1 1973 I 3,730,282

3 Sheets-Sheet l FIGURE 2 INVENTOR v RONALD W. CHAPMAN BY 1., f M

' ATTORNEY Patented May 1, 1973 3 Sheets-Sheet 2 /J A A; g

FIGURE 8 FIGURE 3 FIGURE 4 INVENTOR RONALD w. CHAPMAN BY /a M ATTDRNEY 3 Sheets-Sheet S N 00 LO\ LO 0 J 5; (13 6 qr v I v m (\1 st A Q "We 2 N O 7 00 L0 t/ Q l O [U N (\1 9 FIGURE 6- FIGURE 7 FIGURE 5 INVENTOR RONALD W, CHAPMAN ATTORNEY MECHANICALLY ORIENTED PERFORATING SYSTEM BACKGROUND OF THE INVENTION Early perforating techniques involve running a wire line perforating gun in a cased hole, perforating the desired formation, removing the perforating gun and then running tubing into the well. For a number of reasons well known to those skilled in the art, it is now preferred practice to run a string of production tubing into the well, set necessary packers, remove mud or completion fluid from below the packer, run aperforating gun through the tubing, perforate the desired formationand then remove the perforating gun. The problems associated with this technique have been largely solved in perforating single completion wells or in perforating the lower formation of a multiple completion well.

When perforating an upper formation in a multiple completion well having multiple tubing strings, it is necessary to orient the perforating gun to avoid the rupturing of an adjacent tubing string which extends to a lower formation. Numerous systems have been proposed by the prior art to mechanically orient a gun for perforating adjacent a long tubing string without rupturing the same. One type of device for this purpose is, called a sidekicker and is disclosed in U.S. Pat. Nos. 3,168,141; 3,338,317 and 3,419,088. Devices of this type typically comprise a plurality of moving parts some or all of which are apt to malfunction atinopportune moments. Another type of orienting device for through-tubing perforating guns are key way devices which typically comprise a properly oriented guide slot on the short tubing string which acts as a cam and suitable guide lugs on the perforating gun to rotate the perforating gun during its terminal downward movement to position the perforating elements in the desired location. Typical disclosures of this type are found in US. Pat. Nos. 3,012,608; 3,031,968; 3,154,147 and 3,361,204. A major disadvantage of this type orienting device is that the guide slot tends to accumulate debris and accordingly cannot function properly to orient the perforating gun. I

Other disclosures of interest with respect to this invention are found in US. Pat. Nos. 3,104,710 and 3,104,718 where a perforating gun is illustrated as having a depending orienting device cooperating with a properly oriented guide mechanism carried by the short tubing string. Also of interest are [1.8. Pat. Nos. 1,636,032; 2,081,294 and 3,349,845 which show an inclined plane within a drill string to sidetrack a hole to be drilled.

SUMMARY OF THE INVENTION It is an object of this invention to provide a simple system for mechanically orienting a perforating gun which is not apt to malfunction and which is not susceptible of collecting debris rendering the system inoperative.

Another object of this invention is to provide a well assembly comprising long and short tubing strings ing gun and a positioning and orienting assembly depending therefrom including orienting means for turning the perforating gun about the long axis thereof and an end-of-tubing locator disposed below the orienting means for sensibly engaging the lower end of a tubing String.

Another object of the invention is to provide apparatus for orienting a through-tubing perforating apparatus comprising an elongate perforating gun lowerable through a tubing string having a plurality of oriented perforating elements thereon and orienting means rigid with the perforating gun and lowerable therewith for turning the perforating gun about the long axis thereof.

Another object of the inventionis to provide well perforating apparatus including an electrically fired perforating gun, means for orienting the perforating gun in a tubing string, an end-of-tubing locator and means preventing firing of the perforating gun until the gun is properly oriented and until the end-of-tubing locator sensibly engages the lower end of the tubing string.

One aspect of this invention comprises a well perforating apparatus comprising an, elongate perforating gun and a positioning and orienting assembly. depend ing therefrom and comprising an; orienting means for engaging an orienting mechanism in the lower part of a tubing string for turning the perforating gun about the long axis thereof and an end-of-tubing locator disposed below the orienting means and passable throughthe orienting mechanism for detecting the lower tubing end. 3

Another aspect of this invention comprises a well as sembly comprising first and second spaced apartwell conduits, guide means for cooperating between the conduits for orienting the secondconduit with respect to the first conduit, and. orienting means in the lower part of the second conduit for turning an elongate tool,

lowerable through the second conduit about the long axis thereof wherein the orienting means comprises a surface inclined to the axis of the second conduit progressively closing a greater part ofthe cross sectional area thereof 'upon approaching the lower end thereof. t

A further aspect of this invention .comprises apparatus for orienting a through-tubingperforating apparatus comprising an elongate perforating gun lowerable through a tubing. string having a plurality of operative perforating elements disposed in predetermined manner about the periphery thereof; and orienting means rigid with the perforatinggun and lowerable therewith for turning the perforating gun about the long axis thereof wherein the orienting means includes a side downwardly inclined to the long axis of the perforating gun.

BRIEF DESCRIPTION OF THE DRAWINGS perforating apparatus of this invention;

FIG. 4 is an enlarged cross sectional view of the well assembly of FIGS. 1 and 2 taken substantially along line 4-4 of FIG. 2 and illustrating the perforating apparatus of FIG. 3 being inserted therein;

FIGS. 5-7 are views showing the sequence of operation of the well perforating apparatus of this invention; 'and FIG. 8 is a schematic view of an electrical diagram for firing the perforating gun.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, a bore hole 10 has been drilled through a plurality of permeable formations, one of which is illustrated at 12. A string of production casing 14 is bonded to the bore hole 10 as by a cement sheath 16. A long tubing string 18 is disposed in the casing 14 and extends below a production packer 20.

. Although not illustrated, a lower permeable formation is placed in communication with the tubing string 18 in any conventional manner. The long string 18 extends through an upper production packer 22 toward the surface. An upper or short tubing string 24 extends through the packer 22 toward the surface to provide a flow path between the surface and the permeable formation l2. Suitable centralizers, slip joints and other typical production equipment may be used to position the

tubing strings

18, 24 as is well known in the art.

As shown in FIG. 1, the formation 12 has been perforated by bullets, shaped charges or the like to form perforations 26 through the casing 14 and the cement sheath l6. Burrs 28 are typically formed on the exterior of the short tubing string 24 during the perforating operation. As illustrated in FIG. 1, the perforations 26 are disposed in a vertical plane extending substantially oppositely to the long tubing string 18. The perforations 26 need not be in a vertical plane nor need they be exactly oppositely directed from the long string 18. It is, of course, imperative that the perforations 26 not penetrate the long tubing string 18.

To this end, the well assembly of FIG. 1 is illustrated as comprising first guide means 30 extending from the exterior of the long tubing string 18 and second guide means 32 extending from the exterior of the short tubing string 24. The second guide means 32 is preferably connected to an orienting sub 34 which may be attached to or considered part of the lower end of the short tubing string 24. If desired, the guide means 30 may be secured to the long tubing string 18 above the level of the orienting sub 34 and the guide means 32 may be secured to part of the tubing string 24 above the orienting sub 34.

The guide means 30, 32 may be of any desired type and installed in any desired manner. The guide means 30 may conveniently comprise a collar 36 welded to the tubing string 18 before running in the well. The guide means 32 comprises an elongate lug 38 extending from the exterior of the sub 34 as shown in FIGS. 1 and 2. The collar 36 is designed such that the orienting sub 34 cannot twist as much as 90 degrees from the position illustrated in FIG. 2 since the lug 38 will either abut the tubing string 18 or the end of the collar 36. In

, use the long tubing string 18 having the guide means 30 thereon, the

production packers

20, 22 and that portion of the short tubing string 18 below the packer 22 are run into the casing 14. The remainder of the tubing string 18 is then run into the casing 14 and landed in the packer 22. Thus the orientation of the guide means 30,32 may be established at the surface without relying on downhole orientation of the tubing string 24.

The orienting sub 34 is best illustrated in F IGS. 2 and 4 where it is shown to comprise a section of tubing 42 of any suitable type, e. g. externally upset or regular. A collar 44 secures the tubing section 42 to the remainder of the tubing string 24. Positioned in the tubing section 42 is orienting means 46 comprising an important part of this invention. The orienting means 46 is illustrated as including a generally wedge shaped structure 48 secured in the tubing section 42 in any suitable manner. The wedge shaped structure 48 provides a surface 50 downwardly inclined with respect to the axis of the tubing 42, progressively closing a greater part of the cross sectional area thereof upon approaching the bottom of the tubing string 24. The surface 50 is preferably planar to avoid accumulation of well debris and the like although smoothly arcuate surface may likewise be satisfactory. The convergence of the wedge shaped structure 48 may vary as desired although a 3 convergence is satisfactory. The surface 50 defines, in part, a passage 52 through the orienting sub 34 which eccentrically narrows to receive and orient a well perforatin apparatus 54.

Referring to FIG. 3, the well perforating apparatus of this invention comprises an elongate perforating gun 56 having a plurality of operative perforating elements 58 disposed around not more than about 310 of the periphery of the perforating gun 56. Since the guide means 30, 32 allow some relative rotation between the tubing strings 18, 24 the operative perforating elements 58 are desirably disposed in a vertical plane. The gun 56 also comprises a wireline attachment 60 for securing a wireline 62 thereto in a conventional manner in order to raise and lower the perforating apparatus 54 through the tubing string 24. 7

Depending from and rigid with the perforating gun 54 is a positioning and orientingassembly 64 comprising as major components a spacing sub 66, orienting means 68 and an end-of-tubing locator 70. The spacing sub 66 is equipped with releasable fastening means, conveniently threaded, on both ends thereof. Spacing subs of different lengths may be provided to position the perforating gun 56 a predetermined distance from the orienting means 68 for reasons apparent to those skilled in the art.

The orienting means 68 comprises an'important part of this invention and includes an elongate body 72 of a size to pass readily through the tubing string 24. The

body 72 includes a side 74 downwardly inclined to the long axis of the perforating gun 54 with the side 74 being disposed to position the perforating elements 58 away from the tubing string 18. The side 74 inclines at substantially the same angle as the surface 50 for engagement therewith. Upon lowering of the perforating apparatus 54 into the orienting sub 34, any misalignment of the side 74 and surface 50 will act to rotate the orienting means 68 and consequently the perforating gun 56 about the longitudinal axis thereof to orient the operative perforating elements 58 away from the surface 50. It will be apparent that the surface 50 may be arranged on the opposite side of the tubing string 24 so long as the side 74 is adjusted to position the perforating elements 58 away from the tubing string 18.

The end-of-tubing locator 70 is positioned at the bottom of the orienting means 68 and is sized to pass through the bottom of the passage 52 as shown in FIGS. 4 and 5. The locator 70 is disposed in a slot 76 in the bottom of the body 72 and comprises a latch or lug 78 mounted by a pin 80 for sequential pivotal movement from a travelling position(FlG. 4), a partially extended position (FIG. 5),I a fully extended position (FIG. 6) and a second travelling position (FIG. 7) for upward movement through the tubing string 24. A suitable spring 82 biases the lug 78 from the travelling position shown in F IG. 4 toward the partially extended position of FIG. 5. A low order shear pin 84 is positioned in the pathof movement of the latch 78 to resist further rotation thereof as the locator 70 emerges from the end of the tubing string 24.

As the end-of-tubing locator 70 exits from the passage 52, the latch 78 is biased to position shown in FIG. 5. This situation maybe sensed by the wire line operator since the well perforating assembly 54 is supported by the surface 50 and little or no tension is sensed in the wireline 62. Pulling on the wireline 62 places the latch 78 in engagement with the wedge like structure 48 or the bottom of the tubing string 24 depending on the design of the latch 78 and the orientation thereof. Tensioning the wireline 62 a predetermined amount, for example 300 pounds, causes the latch 78 to shear the low order pin 84 and abut a high order shear pin 86 as shown in FIG. 6. Shearing of the low order pin 84 is sensible at the surface since the tension in the wireline 62 increases to the predetermined amount and then decreases since the perforating assembly 54 moves a short distance upwardly in the tubing string 24. I

FIG. 6 illustrates the perforating position of the assembly 54. The distance between the latch 78 and the perforating elements 58 are known by measurement at the surface. The length of the spacing sub 66 is selected at the surface before running the perforating apparatus 54 to place the operative perforating elements 58 a predetermined distance above the lug 78. It will accordingly be seen that the end-of-tubing locator facilitates positioning of the perforating gun 576 in the desired position.

An important part of this invention resides in an elec- -.trical control network 88 illustrated in FIG. 8. The network 88 includes conventional control wires 90,92 comprising part of the wireline 62. The control wire 90 passes into the perforating gun 56 in communication with conventional perforating gun circuitry which is illustrated as comprising a safety resistor 94 and a parallel firing circuit 96. The spacing sub 66 is equipped with an electrical path 98 leading from the perforating gun circuitry to an electrical path 100 in the orienting 'means 68.

The electrical path 100 is connected to a first switch 102 which may comprise a conventional hermetically sealed microswitch disposed in a recess 104 communicating with the side 74.0f the orienting means 68. The

switch 102 is connected in series by an electrical path 106 to a second switch 108 positioned in the path of movement of the lug 78 for operation thereby in the fully extended position shown in FIG. 6. The second switch 108 may comprise another hermetically sealed conventional microswitch connected by an electrical path 110 to an electrical path 112 in the spacing sub 68 which in turn is connected to an electrical path 114 to the control wire 92. The network 88 may be grounded in any suitable manner as by a ground connection 1 16.

It will be apparent that the firing circuit 96 cannot be actuated until the

switches

102, 108 are both closed. Consequently, the perforating gun 56 cannot be fired until the orienting surface 74 is flush with the surface 50 and the lug 78 has been moved to and retained in the fully extended position of FIG. 6. It will accordingly be seen that the electrical network 88 is a simple and expeditious means of preventing premature firing of the perforating gun 56.

Upon firing of the perforating gun 56, the short tubing string 24 is ruptured and the perforations 26 formed in the formation 12 as shown in FIG. 1. It then becomes necessary to remove the perforating apparatus 54 from the tubing string 24. The wireline 62 is accordingly tensioned to a second predetermined force, preferably substantially in excess of the force necessary to rupture the low order shear pin 84, in order to rupture the high order shear pin 86. The second predetermined force may, for example, be in the neighborhood of 1,000 pounds. The high order shear pin 86 fails allowing the lug 78 to rotate by contact with the wedge shaped structure 48 into the second travelling position illustrated in FIG. 7. The perforating apparatus 54 is then removed from the tubing string 24 by reeling in the wireline 62.

It will accordingly be seen that there is provided a simple mechanically oriented perforating system.

In a preferred embodiment of the invention, the short tubing string 24 is slotted along its axis in a location that provides a window through which the jets or bullets from the perforating elements 58 are directed when the gun 56 is aligned bythe mating of the tubingattached and gun-attached wedge shaped orienting means 46 and 68. Where desirable, the orienting means 46 in the tubing string 24 can be located above the end of the string. The end of tubing locator 70 contains latch 78 which engages the bottom edge of wedge shaped portion 48 of the tubing-attached orienting means 46. This is, in effect, the end of the tubing, in the sense that passage through the tubing is impeded by the presence of the wedge 48.

I claim as my invention:

1. Well perforating apparatus for perforating through a tubing string having an orienting mechanism in the lower part thereof, the apparatus comprising an elongate perforating gun having a wire-line attachment on the upper end thereof; and a positioning and orienting assembly depending from the perforating gun comprising orienting means for engaging the orienting mechanism and turning the perforating gun about the long axis thereof; and

an end-of-tubing locator disposed below the orienting means and passable through the orienting mechanism for detecting the lower tubing end.

2. The apparatus of claim 1 wherein the end-of-tubing locator comprises a latch mounted for biased movement from a travelling position toward an extended position for engaging the underside of the bottom of the tubing string.

3. The apparatus of claim 1 wherein theperforating gun includes an electrically operated firing circuit and the apparatus further comprises means for activating the gun firing circuit comprising a first switch adjacent the end-of-tubing locator and actuated thereby during detection of the lower tubing end;

a second switch carried by the orienting means and actuated by contact with the orienting mechanism upon engagement therewith; and

circuit means for operating the gun firing circuit only upon operation of both the first and second switches.

4. The apparatus of claim 3 wherein the circuit means comprises means connecting the first and second switches in series.

5. In a well assembly comprising first and second spaced apart well conduits; first guide means extending from the exterior of the first conduit above the bottom thereof; second guide means extending from the exterior of the second conduit adjacent the lower end thereof in mating engagement with the first guide means for orienting the second conduit with respect to the first conduit; and orienting means in the lower part of the second conduit for turning an elongate tool, lowerable through the second conduit, about the long axis thereof, the improvement wherein the orienting means comprises a surface inclined to the axis of the second conduit progressively closing a greater part of the cross sectional area of the second conduit upon approaching the lower end thereof.

6. The well assembly of claim 5 wherein the surface is generally planar.

7. The well assembly of claim 5 wherein the first guide means comprises a collar and the second guide means comprises a lug.

8. The well assembly of claim 5 wherein the inclined surface is adjacent the first conduit.

9. Apparatus for orienting a through-tubing perforating apparatus comprising an elongate perforating gun lowerable through a tubing string having a plurality of operative perforating elements disposed around not more than about 310 of the periphery of the perforating gun;

orienting means rigid with the perforating gun and lowerable therewith for turning the perforating gun about the long axis thereof, the orienting means including a side downwardly inclined to the long axis of the perforating gun; and

an orienting sub for attachment to a tubing string for receiving the orienting means and turning the same about the long axis of the perforating gun, the sub having a passage therethrough including a downwardly inclined side generally parallel to the side of the orienting means for engagement therewith.

10. The apparatus of claim 9 wherein the side is disposed in the sector free from operative perforating elements.

11. The apparatus of claim 9 wherein the orienting means depends from the perforating gun.

12. The apparatus of claim 9 further comprising means for positioning the orienting sub relative to another tubing string for disposing the inclined side of the sub passage in predetermined relation to another tubing string.

13. The apparatus of claim 12 wherein the positioning means extends from the exterior of the orienting sub.

14. A process for perforating a casing in a well that contains at least one tubing string, comprising:

attaching a wedge shaped element with thin edge down to a perforating gun;

attaching a wedge shaped element with thin edge up within a tubing string;

positioning and orienting said perforating gun by lowering the gun and attached wedge shaped element through said tubing string into contact with the wedge shaped element attached to the tubing string;

moving a latching means attached to said perforating gun into latching engagement with an element attached to said tubing string when said wedge shaped elements are substantially in contact with each other; and

verifying that said wedge shaped elements are substantially in contact with each other by raising the perforating gun until that motion is distinguishably resisted by said latching means.

15. In a well completion process in which spaced apart long and short well conduits are installed within a cased portion of a well borehole with guide means attached to the exteriors of the conduits near the end of the short conduit, for maintaining their relative orientation, and a tool orienting means positioned within and near the end of the short conduit, for turning an elongated tool being lowered through the conduit about the long axis of the tool, the improvement which comprises:

positioning within and near the end of the short conduit a surface which is inclined to the axis of the conduit and progressively closes a greater portion of the cross-sectional area of the conduit as it approaches the end of the conduit; and

attaching said inclined surface to the short conduit to provide said tool orienting means.

16. The process of claim 16 in which the well is perforated by:

providing the lower end of a perforating gun with an inclined surface that is adapted to engage and be turned by the inclined surface position within and near the lower end of the short conduit;

lowering said perforating gun through the short conduit;

turning said perforating gun to the extent required to attain a selected orientation relative to the long conduit by moving the gun so that said inclined surfaces are moved into a substantially face-toface contact with each other; and

actuating said perforating gun to perforate the casmg. 17. The process of claim 17 in which the attainment of the selected perforating gun orientation is verified by:

attaching to said perforating gun, in a position below said inclined surface, and end of tubing locator means that is adapted to be lowered through the short conduit beyond the tool orienting inclined surface mounted within the conduit and to indicate its arrival at the end of the conduit;

adjusting the position of said end of tubing locator relative to the positions of the inclined surfaces on the perforating gun and the short conduit, so that the end of tubing locator does not arrive at the end of the conduit until the inclined surfaces have become substantially contiguous; and

the end of tubing has been indicated by the end of tubing locator.

Claims

1. Well perforating apparatus for perforating through a tubing string having an orienting mechanism in the lower part thereof, the apparatus comprising an elongate perforating gun having a wire-line attachment on the upper end thereof; and a positioning and orienting assembly depending from the perforating gun comprising orienting means for engaging the orienting mechanism and turning the perforating gun about the long axis thereof; and an end-of-tubing locator disposed below the orienting means and passable through the orienting mechanism for detecting the lower tubing end.

3. The apparatus of claim 1 wherein the perforating gun includes an electrically operated firing circuit and the apparatus further comprises means for activating the gun firing circuit comprising a first switch adjacent the end-of-tubing locator and actuated thereby during detection of the lower tubing end; a second switch carried by the orienting means and actuated by contact with the orienting mechanism upon engagement therewith; and circuit means for operating the gun firing circuit only upon operation of both the first and second switches.

6. The well assembly of claim 5 wherein the surface is generally planar.

9. Apparatus for orienting a through-tubing perforating apparatus comprising an elongate perforating gun lowerable through a tubing string having a plurality of operative perforating elements disposed around not more than about 310* of the periphery of the perforating gun; orienting means rigid with the perforating gun and lowerable therewith for turning the perforating gun about the long axis thereof, the orienting means including a side downwardly inclined to the long axis of the perforating gun; and an orienting sub for attachment to a tubing string for receiving the orienting means and turning the same about the long axis of the perforating gun, the sub having a passage therethrough including a downwardly inclined side generally parallel to the side of the orienting means for engagement therewith.

14. A process for perforating a casing in a well that contains at least one tubing string, comprising: attaching a wedge shaped element with thin edge down to a perforating gun; attaching a wedge shaped element with thin edge up within a tubing string; positioning and orienting said perforating gun by lowering the gun and attached wedge shaped element through said tubing string into contact with the wedge shaped element attached to the tubing string; moving a latching means attached to said perforating gun into latching engagement with an element attached to said tubing string when said wedge shaped elements are substantially in contact with each other; and verifying that said wedge shaped elements are substantially in contact with each other by raising the perforating gun until that motion is distinguishably resisted by said latching means.

15. In a well completion process in which spaced apart long and short well conduits are installed within a cased portion of a well borehole with guide means attached to the exteriors of the conduits near the end of the short conduit, for maintaining their relative orientation, and a tool orienting means positioned within and near the end of the short conduit, for turning an elongated tool being lowered through the conduit about the long axis of the tool, the improvement which comprises: positioning within and near the end of the short conduit a surface which is inclined to the axis of the conduit and progressively closes a greater portion of the cross-sectional area of the conduit as it approaches the end of the conduit; and attaching said inclined surface to the short conduit to provide said tool orienting means.

16. The process of claim 16 in which the well is perforated by: providing the lower end of a perforating gun with an inclined surface that is adapted to engage and be turned by the inclined surface position within and near the lower end of the short conduit; lowering said perforating gun through the short conduit; turning said perforating gun to the extent required to attain a selected orientation relative to the long conduit by moving the gun so that said inclined surfaces are moved into a substantially face-to-face contact with each other; and actuating said perforating gun to perforate the casing.

17. The process of claim 17 in which the attainment of the selected perforating gun orientation is verified by: attaching to said perforating gun, in a position below said inclined surface, and end of tubing locator means that is adapted to be lowered through the short conduit beyond the tool orienting inclined surface mounted within the conduit and to indicate its arrival at the end of the conduit; adjusting the position of said end of tubing locator relative to the positions of the inclined surfaces on the perforating gun and the short conduit, so that the end of tubing locator does not arrive at the end of the conduit until the inclined surfaces have become substantially contiguous; and actuating said casing perforation after the arrival at the end of tubing has been indicated by the end of tubing locator.