US3209828A

US3209828A - Perforating apparatus

Info

Publication number: US3209828A
Application number: US234783A
Authority: US
Inventors: Maurice P Lebourg
Original assignee: Schlumberger Well Surveying Corp
Current assignee: Schlumberger Well Surveying Corp
Priority date: 1962-11-01
Filing date: 1962-11-01
Publication date: 1965-10-05
Anticipated expiration: 1982-10-05

Description

Oct. 5, 1965 M. P. LEBOURG PERFORMING APPARATUS 2 Sheets-Sheet l Filed NOV. l, 1962 INVENTOR.

Wwf/JM Oct. 5, 1965 M. P. LEBQURG PERFORATING APPARATUS 2 Sheets-Sheet 2 Filed Nov. l, 1962 Maar/ce scu/y BMM/1 M4@ United States

Patent

33,2%,828 Patented @on Ei, i965 3,209,828 PERFORATlNG APPARATUS Maurice P. Lebourg, Houston, Tex., assignor to Schlumberger Well Surveying Corporation, Houston, Tex., a corporation of Texas Filed Nov. 1, 1962, Ser. No. 234,783 3 Claims. (Cl. 16d-55.1)

This invention relates to apparatus useful for independent completion of one or more co-extensively extending tubing strings which are disposed in a common oil well borehole. In particular, this invention relates to new and improved apparatus for locating adjacent strings of tubing from a given large diameter string of tubing in a well bore with a greater degree of accuracy, and perforating the given string of tubing in a selected direction of orientation.

The technique of multiple completion involves the positioning of co-extending strings of tubing in a common borehole, cementing the strings in place in the borehole, and using orienting perforating apparatus to selectively perforate one or more of the tubing strings. The orientking perforating apparatus generally includes a pipe or tubing locating apparatus, an indexing device and a directional perforating device which are lowered into one string of tubing to a depth where perforations are desired. The adjacent tubing strings are located by indexing the pipe locating apparatus and the directional perforator is then oriented relative to the co-extending strings of tubing so as to lire in a selected direction, typically away from the other strings of tubing. Each string of tubing is completed in this manner. Heretofore, multiple completion of wells has been limited to tubing strings having a small diameter, say 2 or 21/2 inches, and oriented perforator apparatus is correspondingly sized for operation in this small diameter tubing. Howevera where the string of pipe has a substantially larger diameter, say 41/2 inches, the small diameter orienting perforating apparatus is generally inadequate for several reasons. First of all, the apparatus, when centered in the large diameter casing, has a large standoff distance thereby reducing the performance of the perforating apparatus. The pipe or tubing locating apparatus, which generally is a radioactivity device, has a tremendously decreased sensitivity because of the large standoff spacing and it is, in fact, extremely dilicult to detect the presence of adjacent strings of tubing because of this large standoff.

An obvious solution to this problem is, of course, to increase the diameter of the orienting perforating apparatus to a size comparable to the large diameter casing. But, such a solution requires duplicate tools in a range of sizes, and larger diameter tools correspondingly have increased weight and raise difficulties in orienting the apparatus successfully.

Accordingly, the present invention is to provide new and improved small diameter orienting perforating apparatus for use in large diameter strings of tubing.

Another object of the present invention is to provide new and improved small diameter orienting perforating apparatus for use in a range of different diameter tubing strings.

A still further object of the present invention is to provide new and improved small diameter orienting perforating apparatus providing increased accuracy of orientation and perforating performance in large diameter well bores.

The present invention includes an assembly of small diameter perforating apparatus, radioactivity pipe locating apparatus and indexing means with interconnecting positioning means arranged to position the perforating apparatus and locating apparatus proximate to the wall of the tubing string in which it is positioned.

The novel features of the present invention are set forth with particularity in the appended claims. The .present invention, both as to its organization and manner of operation together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings in which:

FIG. l is a view illustrating apparatus of the present invention disposed in a well bore;

FIG. 2 is a view in cross-section taken along line 2-2 of FIG. 1;

FlG. 3 is a view in cross-section taken along line 3 3 0f FIG. l;

FG. 4 is a View in cross-section illustrating pipe strings in a well bore and apparatus in one pipe string; and

FlG. 5 is a partial plan view of indexing means.

Referring now to FIG. 4, a large diameter string of pipe lid and small diameter string of pipe ltla are shown traversing the earth formations lil and cemented in place by `a column of cement l2. Shown positioned in the string of pipe lll is orienting perforating apparatus 13 according to the present invention. The assembled apparatus 13 is adapted to be lowered into the pipe string l@ by means of an electric armored cable ld (FIG. l) spooled from a winch (not shown) at the earths surface in a conventional manner. The pipe string ill is typically filled with a well control fluid such as mud.

As shown in FIG. l, the apparatus lf3 includes a conventional casing collar locator l5 connected to an indexing device lo, a directional radioactivity pipe locating means i7 and a directional perforator i3. The elements 1648 are sized to pass through a small diameter tubing which is the range of tuhings in 2 and 21/2 inch sizes.

The indexing device la generally includes a tubular mandrel 19 and a tubular cage 2i) slidably received thereon. Cage 2t) is sized to be passed through a small diameter tubing but has attached, peripherally spaced, bow springs 2l sized for frictional engagement with the pipe ill. Mandrel i9 has a slot system 22 in its outer surface while cage 2li has a follower 23 for the slot system. Follower 23 may, for example, be a spring clip ring with an end portion extending through the cage Ztl into register with the slot, the end portion being resiliently movable inwardly and outwardly relative to the cage 2li.

As shown in partial view in PEG. 5, the slot system 2l includes longitudinal slots 2d and transverse connecting slots 25. rl`he end portion of the spring clip ring is shown at 2o. The slots 2li and 2S have inclined portions 27 which extend from a bottom surface of a slot to a shoulder 28 to a point below the outer surface of the mandrel i9. In operation, if the end portion 2d is in a longitudinal slot, it will be guided up an inclined surface 27 and over a shoulder 23 when the mandrel is moved relative to the cage in an upward direction. Movement then in a downward ldirection will bring the end portion 26 into engagement with a shoulder 2%, and end portion 2d will be guided into a transverse slot 25 to rotate the mandrel until the end portion 26 passes over a shoulder 28 of the longitudinal slot.

The directional radioactivity pipe locating means i7 includes a focussed source of radioactivity 3i) and spaced therefrom a suitable distance a focussed detector of radioactivity 31. These devices may, for example, be a gamma radiation source such as Cs 137 and a Geiger-Mueller tube. These devices cooperate in a well-known manner so that radioactivity induced by the source is detected in a directional manner by the detector tube. The directional sensitivity is shown by the arrow 34 in FIGS. 2, 3. For optimized sensitivity, the source and detector should be located proximate to the wall of the tubing in which they are positioned.

The perforating apparatus 1S may, for example, be of the type illustrated in my Patent No. 3,048,102 where the shaped charges are all oriented to iire in a single direction as illustrated by the arrow 33 in FIGS. 2 and 3.

interconnecting the indexing device 16 and the radioactivity pipe orienting device i7 is a coupling member 3d having a centered end 37, an eccentered end 38, and an intermediate centered portion 39. The centered end 37 has a first opening 40 about a first axis 41, the axis dit being coextensive with the central axis of the pipe l@ when the apparatus is centered in the pipe l0. Opening 40 extends into the intermediate portion 39, the opening 40 having a threaded portion adapted to receive a threaded end of the indexing device 16. The intermediate portion 39 has an outer cylindrical surface which is concentrically arranged relative to the tirst opening liti and sized to a diameter just slightly less than the diameter of the large diameter casing, say on the order of 1/2 inch. In the eccentered end 38 of the coupling member is a second opening 43 about a second axis i4 which is offset and parallel to axis 4l. Opening 43 extends into the intermediate portion 39 and opens to the first opening 40. The second opening 43 also has a threaded portion adapted to receive a threaded end of the pipe locating apparatus 17. The common plane defined by the first and

second axes

41, 44 is here dened as a plane or orientation and identified by the numeral 45. The directional sensitivity 34 of the pipe locating means ll? and the direction of tiring 33 of the perforating apparatus i8 lie in plane 45 but face in opposite directions.

Another coupling member 36a interconnects the pipe locating apparatus 17 and a centralizer sub 47, the coupling member 36a being reversed in position relative to the coupling member 36 so that the axis of the opening in the eccentered end 38a. coincides with the axis 44 of coupling 36 while the axis of the opening in the centered end 37 coincides with the central axis of the centralizer sub 47 and the central axis 41 of the pipe 10. The centralizer sub 47 has the usual bow springs 48 thereon for centering the apparatus in the pipe il() and is constructed so that a mandrel is rotatable relative to the outer tubular cage which has the springs 58.

From the foregoing, it will be appreciated that

coupling members

36, 36a are identical but reversed in position so that pipe locating device 17 is eccentered relative to the central axis 4i of the pipe 310, the pipe locating device, however, being within an imaginary cylindrical envelope defined by the cylindrical intermediate portions 39, 39a of the coupling members. The intermediate portions 39, 39a protect the device 17 from damage in the pipe while insuring the close positioning of the device 17 to the wall of the pipe.

At the lower end of the centralizer sub 47, another pair of coupling members 36h, 36C are reversely positioned and connected to the ends of the perforator 18 so that the axis 44a of the perforator is eccentered with respect to the central axis of the pipe i0, the perforator device, however, being within an imaginary cylindrical envelope defined by the intermediate portions 39h, 3% of the coupling members.

From the foregoing description it will be appreciated that the apparatus disclosed resembles a crankshaft wherey the apparatus is centered in a pipe but has components thereof displaced radially from the central axis of the apparatus to place such components proximate to the wall of the pipe.

In operation, the apparatus is lowered in the pipe to the level to be perforated. Bow springs 2l and d8 centralize the apparatus in the pipestring. The cable 14';- is then lifted up a short distance to bring the index pin in the lower end of the slot system and lowered to original position, thus indexing tool to adjacent slot. Radioactivity measurements are made and the cable 14 reciprocated thereby rotating the radioactivity apparatus through the distance between adjacent slots of the slot system. Radioactivity measurements are taken for each rotative position througha 360 arc. From the radioactivity measurements, the location of the adjacent pipestring, or for that matter, any locatable object is determined and the preforator oriented as desired,

While a particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

l. Perforator orienting apparatus for large diameter pipe strings comprising: radioactive pipe-locating means having a given radial direction of sensitivity; an indexing device including wall-engaging means to centraiize the apparatus in such pipe string, and a member rotatable about a central axis of the apparatus relative to said wall-engaging means; perforator means having a given radial direction of fire; means coupling said radioactivity locating means, said rotatable member and said perforator means in fixed relation to one another, said coupling means including an interconnecting member above and coupled to said radioactivity locating means where said radioactivity locating means has a cross-sectional size substantially less than the cross-section of such pipe string, said interconnecting member having an axially offset portion arranged to eccenter said radioactivity locating means relative to the central axis of said apparatus and position said radioactivity locating means proximate to the wall of such pipestring.

2. Perforator orienting apparatus for large diameter pipestrings comprising: an indexing device including wallengaging means for contact with the wall of a pipestring and a member rotatably mounted about a central axis relative to said wall-engaging means, radioactive pipe locating means having a given radial direction of sensitivity; perforating means having a given radial direction of re; said pipe locating means and said perforating means having a cross-section sized for passage through a small-diameter tubing string; and means coupling said rotatable member, said pipe locating means and said perforating means in ixed relation to one another, said coupling means including a pair of interconnecting members having axially olfset connecting portions for each of said pipe locating means and said perforating means arranged to displace said pipe locating means and said perforating means relative to said central axis, said pipe locating means and perforating means being arranged with their respective radial direction of sensitivity and radial direction of lire disposed in opposite directions.

3. As a subcombination, apparatus for use in a pipestring in a well bore having a central axis comprising: radioactivity-sensing means having a given radial direction of sensitivity; means for rotating said radioactivity-sensing means about said central axis; wall-engaging means for centralizing said rotating means along said central axis Within the pipestring; and means dependently coupling said radioactivity-sensing means to said rotating means for eccentering said radioactivity-sensing means relative to said central axis; said coupling means including an axially offset portion arranged to eccentrically displace said radio-f activity-sensing means in said radial direction and into proximity with said pipestring.

References Cited by the Examiner UNITED STATES PATENTS Abendroth 166-555 XR Dunn 175-57 Popham 166--35 True 166--55 Diebold IGZ- 21.8 True 166-55 XR Kenneday et al 166-55.1

CHARLES E. OCONNELL, Primary Examiner.

Claims

3. AS A SUBCOMBINATION APPARATUS FOR USE IN A PIPESTRING IN A WELL BORE HAVING A CENTRAL AXIS COMPRISING: RADIOACTIVITY-SENSING MEANS HAVING A GIVEN RADIAL DIRECTION OF SENSITIVITY; MEANS FOR ROTATING SAID RADIOACTIVITY-SENSING MEANS ABOUT SAID CENTRAL AXIS; WALL-ENGAGING MEANS FOR CENTRALIZING SAID ROTATING MEANS ALONG SAID CENTRAL AXIS WITHIN THE PIPESTRING; AND MEANS DEPENDENTLY COUPLING SAID RADIOACTIVITY-SENSING MEANS TO SAID ROTATING MEANS FOR ECCENTERING SAID RADIOACTIVITY-SENSING MEANS RELATIVE TO SAID CENTRAL AXIS; SAID COUPLING MEANS INCLUDING AN AXIALLY OFFSET PORTION ARRANGED TO ECCENTRICALLY DISPLACE SAID RADIO-