CA3203289A1 - Shaped charge assembly, explosive units, and methods for selectively expanding wall of a tubular - Google Patents

Abstract

A shaped charge assembly for selectively expanding a wall of a tubular includes a housing comprising an outer surface feeing away from the housing and an opposing inner surface facing an interior of the housing. First and second explosive units each includes a predetermined amount of explosive sufficient to expand, without puncturing, at least a portion of the wall of the tubular to form a protrusion extending outward into an annulus adjacent the wail of the tubular.

Description

$HApEo CHARGE ASSEMBLY, EXPLOSIVE UNITS, AND METHODS
FOR SELECTIVELY EXPANDING WALL OF A TUBULAR
CROSS .REFERENCE .To RELATED APPLICATIONS
W011 The present application is a Patent cooperation Treaty (PCT) application that claims priority to, and the benefit of, U.S. Patent Application No. 17/126,982, filed on December 18, 2020 as a continuation-in-patt of UpS. Patent Application No. 16/970,602, filed on August '17, 2020, 'which is a national phase of International PCT Application No, PC112019/046920, filed on August 16, 2019, which claims priority to U,S, Provisional PtOcnt Application No, 62/76408, filed on August 16, 2018, with all prior applications, as set forth above, having the title of "Shaped Charge Assembly, Explosive Units, and Methods for Selectively Eipanding Wall of a Tubular.- The contents of the prior applications are hereby incorporated by reference herein in their entireties, FIELD OF THE INVENTION
[00021 Embodiments of the present invention relate, generally, to shaped charge tools for selectively expanding a wail of tubular goods including, but not limited to, pipe, tube, casing and/or easing liner, in order to compress micro annulus pores and reduce micro annulus leaks, collapse open channels in a cemented annulus, and minimize other inconstancies or defects in the cemented annulus. The present disclosure also relates to methods of selectively expanding a wall of tubular goods to compress micro annulus pores and reduce micro annulus leaks, collapse open channels in a cemented annulus, and minimize other inconstancies or defects in the cemented annulus, The present disclosure further relates to a set of explosive units that may be used in:shaped charge: tools.

BACKOROUND
[0003] Pumping cement into a wellbore may be part of a process of preparing a well for further drilling, production or abandonment The cement is intended to proteet and seal tubulars in the WellbOre,:c:etnenting s COMITIOWOW1 to permanently shut off water and gas Migration into the well. As part of the completion process of a prospective production well:, cement may be used to seal an annulus after a casing string has been run in the wellbore.
Additionally, cementing may be used to seal a lost circulation zone, or an area where there is a reduction or absence of flow within the well. Cementing is used to plug a section of an eNisting well, in order to run a deviated Well from that point Also, cementing may be used to seal off all leak paths from the earth's downhole strata to the surface in plug and abandonment operations, at the end of the Weirs %eh! life.
[0004] Cementing is performed when a cement slurry :is pumped into the well, displacing the drilling fluids still located within the well, and replacing them with cement.
The cement shiny floW$ to the bottom of the wellbore through the casing_ :frOm there, the cement fillS in the annulus between the casing and the actual weilbore, and hardens. This et:WO a seal intended to impede outside materials from entering the Well, in addition to permanently positioning the casing in place. The casing and cement once cured, helps maintain the integrity of the wellbore.
[0005_1 Although the cement material is intended to fOrm a Water tight seal for preventing outside materials and fluids florn entering the Wellbore, the cement material is generally porous and, over time, these outside materials and fluids can seep into the micro pores of the cement and cause cracks, micro annulus leak paths, decay andlOr contamination of the cement material. and the wellbore. Further, the cement in the cemented annulus may inadvertently include open: channels, sometimes referred to as "channel columns" that undesirably allow gas and/or fluids to flow through the channels, thus raising the HSI( of crackk det ay and/or contamination of the cement and wellbore. In other situations, the cement may :inadvertently not be provided around the entire 360 degree circumference of the casing,. This May occur especially in horizontal wells, Where gravity acts on the cement above the caSing:in the hOritontal wellbore. Further, Shifts in the Strata (formation) of the earth may canse Cracks in the cement, resulting in "channel columns" in the cement where annulus flow would otherwise not occur. Other inconsistencies or defects of the atpent. in the annulus may

2 arise from inconsistent viscosity of the cement, oci,ipf from a pressure differential in the formation that causes the cement lobe iticoeli!*tit in different areas of the annulus.
[0006] Therefore, a need exists for systems and methods that are usable to effectively reduce andlor compress micro annulus pores in the cement or other seaiing materials for minim4ingõ
Or eliminating the fOrmation craCks, initto annulus 10*, decay and/or contamination of the cement and wellbore..
[0007] in addition, a need exists for cost effective :systems and methods that are usable to selectively expand a wall or portion of a. wall of tubular gOods to compress micro annulus pores and reduce or eliminate micro annulus leaks.
[0008] A further need exists for Systems and methods that selectively expand a. wall or portion of a wall of tubular goods to effectively collapse and/or compress open channels in a cemented annulus, and/or compress the cemented annulus to cure other defects or inconsistencies in the cement to minimize or eliminate the unintended flow of gas and/or fluids through the cemented annuls.
[0009] The embodiments of the present invention meet all of these needs.
SUMMARY
[0010] At Set forth above, because cement material can be porous, Water, gas, or Other outside materials may eventually seep into the micro pores of the cement, and penetrate through the hardened concrete seal. The seepage, when driven by hydrostatic formation pressure, May Cause cracks, micro annulus leak paths from downhole to surface, decay and/or contamination of the cement, casing and weilbore, And, the cemented annulus may inadvertently include open channels (e.A., "channel columns") that allow gas and/or fluids to flow through the channels, Furthermore, the cement: may inadvertently .riot be provided around the entire circumference of the casing, and may have other inconsistencies or defects due to inconsistent viscosity of the cement, and/or a pressure differential in the formation that causes the cement to be inconsistent in different areas of the annulus.

3 [00111 in view of the foregoing, an object of the present disclosure is to provide tools and methods that compress Micro annulus pores in cement to further reStrittiseal off micro annulus leaks migrating up a cement column in a well bore to conform to industry and/or regulatory standards. Compressing the cement reduces the porosity of the cement by reducing the number of micro annulus pores. The reduced number of micro annulus pores reduces the risk of seepage into the cement as well as the formation of micro annulus leak paths. Another object of the present disclosure is to provide tools and methods that eflectiv-ely collapse and/or compress open channels in a cemented annulus, and/or that effectively compress the cemented annulus to cure other defects or inconsistencies in the cement that would otherwise allow unintended flow of gas and/or fluids through the cemented annuls.
Generally, all deleterious flow through the cemented annulus Caused by the above situations may be referred to as 41111111US flow, and the disclosure herein discusses apparatus and methods for reducing or eliminating annulus flow.
[00121 Explosive, mechanical, chemical or thermite cutting devices have been used in the petroleum drilling and exploration industry to clearlly sever a joint of tithing or casing deeply within a welibote. Such devices are typically Conveyed into a well for detonation on a wireline or length of coiled tubing. The devices may also be pumped downhole.
:Known shaped charge explosive cutters include a consolidated amount of explosive material having an external surface dad with a thin metal liner. When detonated at the axial center of the packed material, at explosive shock wave, which may have a pressure force as high as 3,000,000 psi, can advance radially along a plane against the tiller to fluidize the liner and drive the fluidized liner lineally and radially outward against the surrounding pipe. The fluidized liner forms a jet that hydro-dynamically cuts through and severs the pipe. Typically, the diameter of the jet may be around 5 to 10 mm.
[0013] The inventor of the present application has determined that, in some cases, removing the liner from the explosive material reduces the focus of the explosive shock Wave So that the wall of a pipe or other tubular member is not penetrated or SeVered.
Instead, the explosive shock wave results in a selective, controlled expansion of the wall of the pipe or other tubular member. The liner-less shaped charge has a highly focused explosive wave front where the tubular expansion may be limited to a length of about 10.16 Centimeters (4 inches) along the outside diameter of the pipe or other tubular member. Too much explosive material, even without a liner, may still penetrate the pipe or other tubular member. On the other hand, toe

4

5 PCT/US2021/064072 little 00.10,51V* material may not expand the pipe or other tubular member enough to achieve its intended effeet. Selective expansion of the pipe or other tubular member at strategic locations along the length thereof can compress the cement that is set in an annulus adjacent the wall of the pipe or other tubular member, Or of the wellbore, beneficially reducing the porosity of the cement by reducing the number of micro annulus pores, and thus the associated tiSk of :micro annulus leaks. The expanded wall of the pipe or other tubular member, along with the compressed cement, forms a barrier The expanded wail of the pipe or other tubular member May also collapse and/or compress open channels in a cemented annulus, and/or may compress the cemented ZIMMIUS to cure other defects or inconsistencies in the cement (such as due to inconsistent viscosity of the cement, and/or a pressure differential in the formation).
[0014] One embodiment of the disclosure relates to a shaped charge assembly for selectively expanding at least a portion of a wall of a tubular. The shaped charge assembly may comprise: a housing comprising an outer surface facing away from the housing and an inner surface facing an interior of the h04,441g; a first explosive unit and a second explosive unit, Wherein each of the first explosive unit and the second explosive unit comprises an explosive material, wherein each of the first eXploSive unit and the second explosive unit comprises liner facing the inner surface of the housing. The density of the liner i or can be, 6 gicc or less, and the liner is, or can be, less ductal than copper, nickel, zinc, zinc alloy, iron, tin, bismuth, and tungsten. In this embodiment, the liner is configured to cause the first explosive unit and the second explosive unit, upon ignition, to expand, without puncturing, said at least a portion of the wall of the tubular to form a protrusion extending outward into an annulus adjacent the wall of the tubular.
[0015] in an embodiment, the liner may be formed of a glass material.
[0016] in an embodiment, the liner may be firmed of a plastic material, [00171 In an embodiment, the liner may be perforated.
[0018] In an embodiment, each of the. first explosive unit and the second explosive unit may be geoinetrically symmetrical about an axis of reyO1utio0, [0019) In an embodiment, the density of the liner may be as.yrametric around at least one of the fist explosive unit and the second explosie unit, [0020] In an embodiment, the shaped charge assembly timber comprise: a first backing plate adjacent the first explosive unit,, a aecOnd backing plate adjacent the second explosive unit, en aperture extending along said axis revolution from an outer stirface of the !fitst backing plate to at least an inner surface of the second backing plate, and an explosive detonator positioned along said axis of revolution and externally of the first backing plate.
[0021] Another embodiment Of the diselOtife relates to a shaped charge assembly for selectively expanding at least a portion of a Wall of a tubular. The shaped charge assembly may comprise a housing comprising an outer surface facing away from the housing and an inner surface facing an interior of the housing, a first explosive unit and a second explosive unit, 'Wherein each of the first explosive unit and the second explosive unit comprises an explosive material and a liner, and wherein each of the first exploSive unit and the second explosive unit comprise an exterior surthce facipt; the inner surface of the housing, 'Me exterior surface and the liner can have a generally hemispherical shape, wherein the first explosive unit and the second explosive unit cornpriS,e a predetermined amount of explosive sufficient to expand, without puncturing, said at least a portion of the wall of the tubular to form a protrusion extending outward into an annulus adjacent the wail of the tubular, [0022] in an embodiment, a jet formed by igniting the first explosive Unit and the world explosive unit may be less focused than a jet formed by igniting non-hemispherical explosive units.
[0023] In an embodiment, each of the first explosive unit and the second explosive unit may be ueometricalty symmetrical about an axis of evolution.
[0024) A further embodiment of the disclosure relates to a shaped charne assembly for selectively expanding at least a portion of a wall of a tubular. The shaped charge assembly can comprise: a housing comprising an outer surface facing away from the housing and an inner surface facing an interior of the houSirig; ft first exploSive unit and a second explosive unit. Wherein each of the: fi't.st explosive unit and the second explosive unit comprises an e4),ItiaiNt material and a liner facing the inner surface of the housing; and an extraneous

6 object located between the inner surface of the housing and the liner of 'lot explosive unit and the Second explosive unit, wherein the extraneous object fouls a jet formed by igniting the first explosive unit and the second explosive unit, so that the jet expands, without puncturing Said at least a portion of the wall of the tubular to form a protrusion extending outward into an annulus adjacent the Wall of the tubular.
[00251 In an embodiment, the extraneous object may be one of a foam object, a rubber object, a wood object, and a liquid object.
[00261 In an embodiment,: each of the first eXplosive unit and the second explosive unit may be geotnetrically symmetical about an axis of revolution.
[00271 A further embodiment of the disclosure relates to a shaped charge assembly for selectively expanding at least a portion of a wall of a tubular, in this embodiment, the shaped charge assembly comprises: a housing comprising an outer surface facing away from the housing and an opposing inner surface facing an interior of the housing; a first explosive unit and a second explosive unit, wherein the fipt otplosive unit Comprises an explosive material formed adjacent a first ZifiC zinc alloy backing plateõ wherein the second explosive unit comprises an explosive material formed adjacent to a second zinc or zinc alloy backing plate;
and an aperture extending along said axis from an outer surface of the first zinc or zinc alloy backing plate to at least an inner surface of the second zinc or zinc alloy hacking plate. The first explosive unit and the second explosive unit comprise a predetermined amount of explosive sufficient to expand, without puncturing, said at least a portion of the wail of the tubular to form a protrusion extending outward into an annulus adjacent the wall of the tubular.
[00281 In an embodiment, the housing may be fordied of a zinc Or zinc alloy Material.
[00291 in an embodiment, the shaped charge assembly further comprises an explosive detonator positioned along said axis adjacent to, and externally of, the first zinc or zinc alloy backing plate, [00301 In an embodiment, each of the first backing plate and the second hacking plate comprises an external surface opposite from said explosive material and peipendicular to said

7 axts Of reN.,olution, 40 wherein the external surlace Of at least one of the first .4.inc or 40c.
alloy baCking .plate and the second zinc or .zinc alloy backlog plate has a plurality of blind pockets therein distributed, in a .pattern about said axis of revolution.
[00311 In an embodiment, each of the first explosi'e. unit and the second explosive unit may be symmetrical about an axis of revolution.
[0032] Another embodiment of the disclosure relates to a method of reducing a leak in an annulus adjacent an outer surface of a tubular in a wellboreõ the method comprising: inserting a plug into the tubular, and positioning an expansion tool Within the tubular at a Ideation uphole ..of the plug, wherein the -expansion tool contains an anlount of explosive material based at least in part on a hydrostatic pressure bearing on the tubular, the 'amount of explosive material for producing an .expiOsive: forcee-sufficient to expand, without puncturing, the wall of the tabtflar. The method steps continue by actuating the expansion tool to expand the wall of the tubular radially outward., without perforating or cutting through the wall of the tubular, to tbrm a protrusion that extends into the annulus adjacent the outer surface of the wall of the tubular, wherein the protrusion seals the leak in the annular, [00331 in an enibodimentõ the method further compris.es actuating one or more puncher charges in the tubular to punch holes in the wall of the tubular at a ideation uphole of the plug; mid providing a sealant into the annulus through the holes in the wall of the tubular..
[00141 A further embodiment of the disclOsthe relates to a method of selectively expanding walls of two concentric tubulars comprising an inner tubular and an outer tubular. The method can comprise the steps. of: positioning an expansion tool within the inner tubular, Wherein the expansion toot can contain an amount of explosive material, which is based at least. in part on .a hydrostatic pressure bearing on at. least the inner tubular and the outer tubular, and the amount of exOlOsiVe .marterial -produces an explosive forte suflieient to expand, without puncturing, a wall of the inner tubular and a wall of the outer tubular, The method .steps can continue by actuating: the expansion tool once to expand both the wall of the inner nibular and. the wall of the outer tubular =radially outward., without perforating or cutting through the wall of the inner tubular and the wall of the outer tubular, to form protrusion of the wall-af the inner tubular that extends intC) an annulus between the inner tubular and the outer tubular, and to forth a concentric protrusion of the wall of the outer tubular into an amiulus adjacent the outer surface of the wall of the outer tubular.

8 [0035] Another embodiment of the disclosure relates to a method of selectively expanding a wall of a tubular comprising a central bore. The method can comprise the steps of:
positioning an expansion tool within the tubular, wherein the =expansion tool can contain an amount of explosive material for producing an explosive force sufficient to expand, without puncturing, the wall of the tubular; and actuating the expansion tool to expand the wall of the tubular radially outward, without perforatin or cutting through the wall of the tubular, to fk.vm a protrusion that extends outward from the central bore of the tubular.
The steps of the method can conclude by inserting the selectively expanded tubular into a wellbore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Various embodiments are hereafter described in detail and with reference to the drawings wherein like reference characters designate like or similar elements throughout the several figures and views that collectively comprise the drawing&
[00371 FIG. 1 is a cross-section of an embodiment of a tool, including a shaped charge assembly. IN- selectively expanding at least a portion of a wall of a tubular, [ÃO38] FIG. 2A to FIG. 2F illustrate methods. of selectively expanding at least a portion of the w1l of a tubular using the tool.
[0039] FIG: 2G -to FIG. 21 illustrate embodiments of a tool that may be used in some of the methods illustrated in FIG. 2A to FIG. 2F, [0040S1 FIGS, 21 to 2L illustrate methods of selectively expanding at least a portion of the wall of a tubular surround by formation, [0041] FIGS. 2N-1 and 2N illustrate a method of selectively expanding the wails of two concentric tubular&
[0042] FIG. 3A and FIG, 3B illustrate graphs showing swell profiles resulting from tests of a pipe and an outer housing,

9 [0043] FIG, 4 is a crosS-section of m1 ernbodiment of the tool, including a shaped charge assembly, [0044] FIG. 5 is a cross-section of an embodiment of the tool, including a shaped charge assembly.
[0045] FIG. 6 is a cross4Oction of an embodiment of the tool, including a shaped charge assembly, [0046] FIG, 7 it a plan view of an embodiment of an end plate showing marker pocket borings, [0047] FIG. a is a cross-section view of an embodiment of an end plate along plane 84 Of Fla 7, [0048] FIG, 9 is a bottom plan view of an embodiment of a top sub after detonation of the explosive material.
[0049] FIG. 10 illustrates an embodiment of a set of explosive units.
[0050] FIG: I illustrates a perspective view of exptpsive units in the set, [0051] FIG. 12 shows a plan form view:of an explosive unit in the set.
[0052] [0039] FIG.....3 shows a: plant:ban view of an alternative embodiment of an explosive unit in the set.
[0053] FigS, 14-17 illustrate another embodiment of an exploSive unit that may be included in a set of several similar units.
[0054] FIG, 18 illustrates an embodiment of a centralizer assembly.
[0055] FIG. 19 illustrates an alternative embodiment of a centralizer assembly.

[0056] FIG. 20 illusfrates another embodiment of a centralizer assembly.
[0057] FIGS. 21 and 22 illustrate a further embodiment of a centralizer assembly.
[0058] FIG. 23 is a cross-section of another erribodiment of a tool:.
including a shaped charge =assembly, for selectively expanding at least a portion of a wall of a tubular.
[0059] FIG, 24 is a cross-section of further embodiment of a tool, including a shaped charge assembly, for selectively expanding at least a portion of a wall of a tubular, [0060] FK1. 25 is a cross-section of further embodiment of a toot, including a shaped charge assembly, for selectively expanding at least a portion of a wall of a tubular, [0061] FIGS. 26A-26D illustrate a method of reducing an annulus leak in a wellbore, according to an embodiment.
[0062] FIGS, 27A-27E illustrate another method of reducing an annulus leak in a wellbore, according to an embodiment [0063] FIG 28 is a cross-section of an embodiment of a dual firing end explosive column tool, as assembled for operation, for selectively expanding at least a portion of a wall of a tubular.
[0064] FIG. 29 is an enlargement of Detail A in FIG. 28.
[0065] FIG. 30 is an enlargement of Detail B in FIG. 28.
[0066] FIG. 31 is a cross-section of an embodiment of a dual end firing explosive column tool, as assembled for operation, for selectively expanding at least a portion of a wall of a tubular.
[0067] FIG, 32 is an enlargement of Detail A in FIG. 31, [0068] FIG. 33 is an enlargement of Detail 13 in FIG. 31, [0069] FIGS, 34A: to 34c illustrate a method of selectively expanding at least a portion of the wall of a -tubular Using the dual end firing explosive cOlumn toOL
DETAILED DESCRIPTION OF THE INVENTION
[0070] Before explaining the disclosed embodiments in detail, it is to be understood that the present disclosure is not limited to the particular embodiments depicted or described, and that the invention can be practiced or carried out in various ways. The disclosure and description herein are illustrative and explanatory of one or more presently preferred embodiments and variations thereof, and it will be appreciated by those skilled in the art that various changes in the design, organization, riWarts of operation, strnetures and location, methodology, and use of mechanical equivalents 'Maybe made Without departing from the spirit of the invention, [0071] As well, it should be understood that the drawings are intended to illustrate and plainly disclose presently preferred embodiments to one of skill in the art., but are not intended to be manufacturiniz level drawings or renditions of final prodiacts and may include simplified conceptual views to facilitate understanding or 04lanation.
Further, the relative skit and arrangement of the components May differ from that shown and still operate within the spirit of the invention.
[0072] Moreover, as used herein, the terms 'pp:" and "down", "upper" and "lower", "upwardly" and downwardly". "upstream" and "downstream" ; "above" and "below"
and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some. embodiments discussed herein. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate In the specification and appended claims, the :terms "pipe", "tube", "tubular", "casing" andior 'other tubular goods" are to be interpreted and defined generically to Mean any and all of such elements without limitation of industry usage. Because many varying and different embodiments may be made Within the scope of the concept(s) herein taught, and because many modifications may be made in the embodiments described herein, it is to be understood that the details herein are to be interpreted as illustrative and nowlitniting, 100731 fl:(3. 1 shows tool 10 for Selectively expanding at least a portion of a wall of a tubular, The tool 10 compriSeS a top sub 12 having a threaded internal socket 14 that axially penetrates the "upper" end of the top sub 12. The socket thread 14 prOvides a secure mechanism for attaching the tool 10 with an appropriate wire line or tubing suspension string (not $1)004 PIO tool 10 can have a substantially Circular cross,section, and the outer cOnfiguration of the tool 10 can be substantially cylindrical, The "lower" end of the top sub 12, as shown, can include a substantially flat end thee 15. As shown, the flat end face 15 perimeter of the top sub can be delineated by an assembly thread 16 and an 0-ring seal 18.
The axial center 13 of the top sub 12 can be bored between the assembly socket thread 14 and the end face 1:5 to provide a. socket 30 for an explosive detonator. 31. In some enthodiments, the detonator May comprise a bi-directional booster With a detonation cord.
[0074] A housing 20 don be secured to the top sub 12 by; Ar example, an internally threaded houSing sleeve 22. The 0-ring /8 can seal the interface from fluid invasion of the interior housing volume.. A window section 24 of the housing interior is an inside wall portion of the housing 20 that bounds a cavity 25 around the shaped charge between the outer or base perimeters 52 440 54, In an embodiment, the upper and lower limits of the window 24 are coordinated with the shaped charge dimensions to place the window 'sills" At the approximate mid-line between the inner and outer surfaces of the ejcplOSi've material 60. The housing 20 may be a frangible steel material of approximately 55-60 RoCkWell.
"C" hardness.
[0075] As shown, below the :window :24, the *Ong 20 can be internally terminated by an integral end wall 32 having a substantially flat. internal end-face 33. The external end-face 34 of the end Wall may he frusto-conical about a central end boss 36. A hardened steel centralizer assembly 38 can be secured to the end boss by assembly bolts 39a, 39b, wherein each blade of the centralizer assembly 38 i5 secured with a respective one of the assembly bolts:39a, 39h (ie.., each blade has its own assembly bolt).
[0076] A shaped charge assembly 40 can be spaced between the top sub end face 1.5 and the internal end-lice 33 of the housing 20 by a pair Of resilient, eleettically non-conductiVe, ring spacers 56 and 58. In some embodiments, the ring spacers may comprise silicone sponge washers. An air space of at least 0.25 centimeters (0.1 inches) is preferred between the top sub end face 15 and the adjacent face of a thrust disc 46. Similarly, a resilient, non-conductive lower ring spacer 58 (or silicone sponge Washer) provides an air spec that can be., at W.4 0..25 Centimeters (0:1 inches) between the internal end-face 33 and an adjacent assembly lower end plate 48.
[0077] Loose explosive partieles cm be ignited by impact or friction M
handling, bumping or dtripping the assembly: Ignition that is capable of propagating a premature explosion may occur at contact points between a steelõ shaped charge thrust disc 46 or end plate 48 and a steel housing 20, To minimize such ignition opportunities, the thrust disc 46 and lower end plate 48 can be fabricated of non-sparking brass. In an embodiment, the thrust disc 46 and lower end plate 48 may be formed of zinc, Or a zinc alloy material. For instance, the thrust disc 4 and lower end plate 48 may be formed of zinc powder or powder including zinc, UpOn detonation of the explosive Material 60, the Zinc is cOnsumed by the resulting eXplOsion such that there is very little, if any, debris left over from the thrust disc 46 and lower end plate 48* As a result, there maybe less debris in the well that could later obstruct the naming of other tools in the well. For the same reasons, i.e., to minimize the amount of debris after detonation of the explosive material 60, the housing 20 may also be formed of zinc, or a zinc alloy material, [0078] The outer faces 91 and 93 of the end pates 46 (upper thrust disc or back up plates) and 483 as respectively shown by FIG. 1õ can be blind bored with marker pockets 95 in a prescribed pattern, such as a circle with uniform arcuate spacing between adjacent pockets as illustrated by FIGS. 7 and. The pockets 95 in the outer faces 91., 93 are shallow surface cavities that are stopped short of a complete aperture through the end plates to form selectively weakened areas of the end plates, When the explosive material 60 detonates, the marker pocket walls are converted to jet material. The jet of fluidized end plate material scar the lower end face 15 of the top sub 1./ with impression marks =n a pattern corresponding to the original pockets as Shown by FIG, 9.. When the top sub 12 is retrieved after detonation, the uniformity and distribution of these iptpissitctt) marks 99 reveal, the quality and uniformity of the detonation and hence, the quality of the explosion. For example, if the top sub face 15 is marked with only a half section of the end plate pocket pattern, it May be reliability concluded that only half of the explosive material 60 correctly detonated.
[0079] The explosive material 60 may be formed into explosive 'Units 60 explosive units 60 traditionally used in the composition a shaped charge tools comprises a precisely measured quantity of powdered, high explosive material, such as RDXõ TINS or MIX: The O(Oiet*e: material. 60 may he formed into units 60 shaped as a truncated col*
by placing the explOSive Material in a press Mold fixture. A .preeistly measured quantity of powdered explosive material, such as RDX, RN'S or MIX, is distributed within the internal cavity of the mold. Using a Central core post as a guide mandrel through an axial aperture 47 in the :upper thrust disc 46, the thrust disc is placed over the explosive powder alid the assembly subjected to a specified compression pressure This pressed lamination comprises a half section of the shaped charge assembly 40. The explosive units 60 may be symmetric about a longitudinal axis 13 extending through the units 60.
[0080] The lower half section of the shaped charge assembly 40 can be formed in the same Manner as described aboNie, having a central aperture 02 of about 0,3 centimeters inches) diameter in axial alignment :with thrust disc aperture 47 and the end plate aperture 49.
A complete assembly comprises the contiguous union t)f the lower and upper half sections along the juncture. plane 64. Notably, the thrust disc 46 and end plate 48 are each fabricated around respective annular boss sections 70 and 72 that provide a protective material mass between the respective apertures 47 and 49 and the explosive material 60.
These bosses are terminated by distal end faces 71 and 73 within a critical initiation distance of about 0A3 centimeters (0.05 inches) to about 0:25 .centimeters (0.1. inches) from the assembly juncture plane 64. The critical initiation distance may be increased or decreased proportionally for other sizes. Hence, the explosive material 60 is insulated from an iimition wave issued by the detonator 31 until the woe ain the prox,imity of the juncture plane 64.
[0081] The apertures 47, 49 and 62 for the FIG. I embodiment remain open and free of boosters or other explosive materials. Although an original explosive initiation point for the shaped charge assembly 40 only occurs between the boss end faces 71 and 73, the original detonation event is generated by the detonator 31 outside of the thrust disc aperture 47. The detonation 'woe can be channeled along the empty thrust disc aperture 47 to the empty central aperture 62 in the explosive material, Typie4y, An explosive load quantity Of 38.8 grams (1,4 ounces) of HMX compressed to a loading pressure of 20,7 Mpa (3,000 psi) may require a moderately large detonator 31 of 420 mg (0.02 ounces) HMX for detonation.
[0082] The FIG. 1 embodiment obviates any possibility of oriewation error in the field while loading the housing 20. A detonation wave may be channeled along either boss aperture 47 or 49 to the -kt-)losii,,,e material. 60 around the central aperture 62.
Regardless of which orientation the shaped charge assembly 40 is given when inserted in the housing 20, the detonator 31 will initiate the explosive material O.
[00831 In this embodiment, absent from the explosive material units 60 is a liner that is conventionally provided on the exterior surface of the explosive material and used to cut through the wall of a tubular. Instead, the exterior surface of the explosive material is exposed to the inner surface of the housing 20. Specifically, the housing 20 comprises an outer surface 53 facing away from the housing 20, and an opposing inner surfitce 51 facing an illiefiOr of the housing 20. The explosive units 60 each comprise an exterior surface 50 that faces and is exposed to the inner surface 51 of the housing 20. Describing that the exterior surface SO of the explosive units 60 is ei(pm.3ed to the inner surface 51 of the housing 20 is meant to indicate that the exterior surface 50 of the explosive units 60 is not provided with a liner, as is the case in conventional cutting devices. The explosive units 60 can comprise a predetermined amount of explosive material sufficient to expand at least a portion of the wall of the tubular into a protrusion extending outward into an annulus adjacent the wall of the tubular. 1'ot instance, testing conducted with a 72 grams (2.54 ounces) MIX, 6.8 centmeter (2.7 inches) outer diameter expansion charge on a tubular having a 11A
centimeter (43 inch) outer diameter and a 10.1 centimeter ('198 inch) inner diameter resulted in expanding the outer diameter of the tubular to 13,5 centimeters (532 inches), i.e expansion was limited to a 10,2 centimeter (4 inch) length along the outer diameter of the tubular. It is important to note that the expansion is a controlled outward expansion of the wall of the tubular, and does not cause puncturing, breaching, penetrating or severing' of the Wal I of the tubular. The annulus may be formed between an outer surface of the wall of the tubular being expanded and an inner wall of an adjacent tubular or a formation. Cement located in the annulus is compressed by the protrusion, reducing the porosity of the cement by reducing the number of micro annulus pores in the cement or other sealing agents. The reduced-porosity cement .provides a seal against moisture seepage that WOtild otherwise lead to cracks, decay and/or contamination of the cement, casing and wellbore. The compressed cement may also collapse and/or compress open channels in a cemented annulus, aridior may compress the cemented annulus to cure other defects or inconsistencies in the cement (such as due to inconsistent viscosity of the cement, and/or a pressure differential in the formation).
[00841 A method of selectively expanding at least a portion of the wall of a tubular using the tool 10 described herein may be as {-Mows. The tool 10 is assembled including the housing 20 containing explosive material 60 adjacent two end plates 46, 48 on opposite sides of the explOSive material 60, As discussed in the embodiment above, the housing 20 eompriks an inner surface 51 facing an interior of the housing 20, and the explosive material 60 comprises an exterior surface 50 that faces the inner surface 51 of the housing 20 and is exposed to the inner surface 51 of the housing 20 (te there is to liner on the exterior surface 50 of the explosive material 60), [0085] A detonator 31 (see Fig. 11) can be positioned adjacent to one of the two end plates 40, 48, The tool 10 can then be positioned within an inner tubular Ti that is to be expanded, as shown in Fa 2A. The inner tubular T1 may be within an outer tubular T2, such that an annulti "A" eXists betWeen the outer diameter of the inner tubular TI and the inner diameter of the outer tubular TZ A sealant, such as eement "C" May be provided in the annulus "A":
When the tool 10 reaches the desired location in the inner tubular T1, the detonator 31 is actuated to ignite the explosive material 60: causing a shock wave that travels radially outward to impact the inner tubular Ti at a first location and expand at least a portion of the Wall of the inner tubular Ti radially outward without perforating or putting through the portion of* wall, to form a protrusion "Pr of the inner tubular Ti at the portion of the wail as shown in FIG. 28. The protrusion '1?" extends into the annulus "A". The protrusion "P"
compresses the cement "Cr to reduce the porosity of the cement by reducing the number of micro pores. The compressed cement is shown in FIG, 2B with the label "CC".
The reduced number of micro pores it the compressed cement "CC" reduces the risk of seepage into the cement. FUrther, the protrusion '1'" creates a ledge or barrier that helps seal that portion of the wellbore from seepage of outside materials. Note that the pipe dimensions shown in F [GS.
2A to 2F are exemplary and for context, and are not limiting to the scope of the invention, [0086) The protrusion "Pr may impact the inner wall of the outer tubular12 after detonation of the explosive material 60, in some embodiments, :the protrusion 7" may Maintain contact with the inner wall of the outer tubular T2 after expansiOn :is complete, In other embodiments, there may be a, small space between the protrusion "P" and the inner wall of the outer tubular T2. For instance, the embodiment of Fig. 3B shows that the space. between the protrusion and the inner wall of the outer tubular T2 may be 0,07874 centimeters (0.0310 inches), However, the size of the space will v4,ty depending on several factors, including, but -not limited to, the : ize thickness), strength and material of the inner tubular TI. the type and amount of the explosive material in the explosive units 60, the phygat profile of the exterior SI:04e 50 of the explosive units 60; the hydrostatic pressure heating on the inner tubular Ti the desired size of the protrusion, and the nature Of the *tillbore operation:
The small space between the protrusion "P" and the inner wall of the other tubular 12 may still be effective for blocking flow of cement, .barite, other sealing materials, drilling mud, etc., so long is the protrusion "P" approaches the inner diameter of the outer tubular T2. This is because the viscosity of those materials generally prevents seepage through such a small space. That is, the protrusion may form a choke that captures (restricts flow of) the cement long enough for the cement to set and form a seal. Expansion of the inner tubular Ti at the protrusion "r causes that portion of the wall of the inner tubular TI to be work-hardened, resultinrz in greater yield strength of the wall at the protrusion "P", The portion of the wail haying the protrusion "P" is not weakened. In particular, the yield strength of the inner tubular 11 increases at the protrusion "F% while the tensile strength of the inner tubular TI at the protrusion 1)" decreases only nominally, Expansion of the inner tubular Ti at the protrusion "P" thus strengthens the tubular without breaching the inner tubular Ti.
[00871 The ;.p4nitude of the proU'usion in the embodiment discoed above depends on several factors, including the amount of explosive material in the explosive units 69, the type of explosive thaterialõ the physical profile of the exterior surface 50 of the explosive units 60, the strength of the inner tubular IL the thickness of the tubular wall, the hydrostatic pressure bearing on the inner tubular TI, and the clearance adjacent the tubular being expanded, i.e., the width of the annulus 'A" adjacent the tubular that is to be epanded. In the embodiment if FIG. the physical profile of the exterior surface $0 of the explosive units 60 is Shaped as a side-ways "V". The angle at which the legs of the "V" shape intersect each other may be varied to adjust the size andlor shape of the protrusion_ Generally, a smaller angle will generate a larger protrusion 'P", Alternatively, the physical profile of the exterior surface 50 may he curved to define a generally hemispherical shape, such as shown in the example of HO_ 23, in that ernbodimeni, the exterior surface 50b of the explosive Ian* 60 is shaped*ith a curve or curves, instead of the sideways "V' shape having, an intersection at the convergence of two linear lines as Shown in Figs. I, 2G, 2H, 21, 4-6, 24 and 25. As used herein, the phrase "generally hemispherical shape' means that the exterior surface 50 of the explosive units 60 may have a perfect hemispherical shape, a flattened hemispherical shape, an oblong hemispherical, shape, or a shape formed only of curves or curved lines. in some embodiments, the "generally hemispherical shape" May also mean that the exterior surface 59 of the exploSive units 60 may he composed of a series of three or more linear lines that together -form a concave shape towards the cavity 25 around the shaped charge.
in further embodiments, the "generally hemispherical shape' may include a sideways "U"
shape.
Generally speaking, the "generally hemispherical shape of the explosive units 60 results in such explosive units 60 producing, upon ignition, a jet that is not as focused as the "V" shape explosive units 60. Accordingly, even. when the explosive units 60 having the generally hemispheric& exterior surface 50b include a liner, according to one embodiment herein, the shape of the exterior surface 50b may controlled so that the collapsed liner fbrms a jet that is not focused enough to penetrate the inner tubular Ti. That is, the generally hemispherical exterior surface 50b may be shaped, upon ignition of the explosive units 60, to form the protrusion P' discussed herein without puncturing the inner tubular T1.
[0088j The method of selectively expanding at least a ponion of the wall of a tubular T1 using the shaped charge tool 10 described herein may be modified to include determining the folio win characteristics of the tubular Ti: a material of the tubular TI, a thickness of a wall of the tubular .1`1, an inner diameter of the tubular Ti., an outer diameter a the tubular TI, a hydrostatic pressure bearing on the tubtilar T1, and a size of a protrusion "P" to be formed in the wall of the tubular Ti. Next, the explosive force necessary to expand, without puncturing, the wall of the tubular Ti to tbrm the protrusion is calculated, or determined via testing, based on the above determined material characteristics. As discussed above, the determinations and calculation of the explosive force can be performed via a software program executed on a computer. Physical hydrostatic testing of the explosive expansion charges yields data which may be input to develop computer models. The computer implements a central processing unit (CPU) to execute steps of the program.
The program may be recorded on a computer-readable recording medium, such as a CD-ROM, or temporary storage device that is removably attached to the computer.
Alternatively, the software program may be downloaded from a remote server and stored internally on a memory device inside the computer. Based on the necessary force, a requisite amount of explosive material for the one or more explosive material units 60 to be added to the shaped charge tool 10 is determined. The requisite amount of explosive material can be determined via the software program discussed above.
[0089j The one or more explosive material units 60, having the requisite amount of explosive material, is then added to the shaped charge tool 10. The loaded shaped charge tool 10 is then positioned within the tubular Ti at a desired location. Next, the shaped charge to 10 is actuated to detonate the one or more explosive material units 60, resulting in .a shock wave, as discussed above, that expands the Wall of the tubular Ti radially:Outward, without perforating or cutting through the wall, to form the protrusion "P"_ The protrusion "P"
extends into the annulus "k' adjacent an outer surface of the wall of the tubular TI., [0090] A first series of tests was conducted to compare the effects of sample explosive units 60, which did not have a liner, with a comparative explosive unit that included a conventional liner on the exterior surface thereof The explosive units in the first series had 15,88 centimeter (6_25 inch) outer housing diameter, and were each tested separately in a respective 17,8 centimeter (7 inch) outer diameter test pipe, The test pipe had a .16 centimeter (63 inch) inner diameter, and a 0,89 centimeter (0:35 inch) Wall Thickness, L80.
[0091] The comparative sample explosive unit had a 15.88 centimeter (&25 inch) outside housing diameter and included liners. Silicone caulk was added to foul the liners, leaving only the outer 0:76 centimeters (0.3 inches) of the liners exposed for potential jetting. 77,6 grams (27 ounces) of fliN4X main explosive was used as the eztplosive material. The sample explosive unit had a 15:88 Centimeter (.6.25 inch) outside housing diameter and was free of any liners. 155.6 grams (5,5 ounces) of UNIX main eXplosiVt Was used as the explosive material. The sample "B" explosive unit had a 15:88 centimeter (6.25 inch) outside housing diameter and was free of any liners, 122,0 grams (43 ounces) of HMX main explosive was used as the explosive material.
[0092] The test was conducted at ambient temperature with the following conditions.
Pressure: 20.7 Nipa (3)000 psi). fluid: water. centralized Shooting Clearance:
0.06 centimeters (0,03 inches), The Results are provided below in Table L
Table l Test Summary in 17,8 centimeters (7 inch) 01). x 089 centimeters (0.350 ittb) wail L-80 Main Load MIX Swell Sample (grams) (ounces) (centimeters) (inches) Comparative (with liner) 77.6g 07) 18.5 cm (7.284 inches) A 155.6 g (5.5 oz) 193 em(7,600 inches) 122.0 g (4.3 oz) 18.6 cm (7.317 inches) [0093] The comparative sample explosive. ,unit produced an 18.5 centimeter (718 inch) swell, but the jetting caused by the explosive material and liners undesirably penenated the inside diameter of the test pipe. Samples "A" and "B" resulted in 193 Centimeter (74 inch) and 18.6 centimeter (732 inch) swells (protrusions), respectively, that svere smooth and uniform around the inner diameter of the test pipe.
[0094] A second test Wag performed using the Sample 'A" exploSi*e unit in a test pipe having similar properties as in the first series of tests, but this tin* with an outer housing outside the Wt. pipe to see how the character of the swell in the test pipe Might change and whether a seal could be elected between the test pipe and the outer housing.
The test pipe had a 17.8 centimeter (7 inch) outer diameter, a 16,1 centimeter (632 inch) inner diameter, a 0.86 centimeter (0.34 inch) wall thickness, and a 813,6 Mpa (118 KSI) tensile strength. The outer housing had an 21,6 centimeter (83 inch) outer diameter, 0. 18.9 centimeter (7.4 inch) inner diameter, a 135 centimeter (9,53 inch) wall thickness., and a 723,95 MO
(105 KS1) tensile strength.
[0095] The second test waS conducted at ambient temperature with the following conditions.
Pressure: 20.7 Mpa (3,000 psi), Fluid: Water, Centralized Shooting Clearance', 0.09 centimeters (0,04 inches). Clearance between the 17.8 centimeter (7 inch) outer diameter of the test pipe and the inner diameter of the housing 0.55 centimeters (012 inches). After the sample explosive unit was detonated, the swell on the 17,8 centimeter (7 ineh) test pipe measured at 18,9 centimeters (7.441 inches) x 18.89 centimeters (7,44 inches), indicating that the inner diameter of the outer housing (18.88 centimeters (7.433 inches)) somewhat retarded the swell (19,3 centimeters (7,6 inches)) observed in the first test series involving sample "A": There was thas "bounce back" oldie swell owed by the inner diameter of the outer housing. In addition, the inner diameter of outer housing increased from 18.88 centimeters (7,433 inches) to 18,98 centimeters (7,474 inobeS), The clearance between the Outer diameter of the test pipe and the inner diameter of the outer housing was reduced from 035 centimeters (022 inches) to 0.08 centimeters (0,93 inches), FIG. 3A shows a graph 400 illustrating the swell profiles of the test pipe and the outer housing. FIG
3:13 is a: graph 401 illustrating an overlay of the swell profiles showing the 0,08 centimeter (0,03 inch) resulting clearance, [0096] A second series of tests was performed to compare the performance of a shaped charge tool 10 (with liner-less explosive units 60) having different explosive unit load weights. In the second series of tests, the goal was to maximize the expansion of a 17.8 centimeter (7 inch) outer diameter pipe having a wall thickness cif 1.37 centimeters (0.54 inches), to facilitate operations on a Shell North Sea Puffin well. Table 2 shows the results of the rests.
Table 2 Centralized Shooting M.ax Swell of 7"
Explosive Unit Load Clearance 0.1).
Pipe Test Explosive Weight Weigh tit 175 g HMX =125 g 0.26 cm 18.8 cm (4.4 oz,) (0.103 inches) (7.38 inches) 217 g HMX 145g 0,26 ern 19.04 CM
(7.65 oz.) (5,11 oz.) (0,103 inches) (7.49 inches) 350 g HMX 204 g 0.26 cm 20.2 cm (12,35 oz.) (7,2 oz.) (0.103 inches) (7.95 inches) [00971 Tests #1 to #3 used the shaped charge tool 10 having liner-less explosive units 60 with progressively increasing explosive weights. In those tests, the resulting swell of the 17.8 centimeter (7 inch) outer diameter pipe continued to increase as the explosive weight increased. However, in test #3, which utilized 350 puns (12.35 ounces) SIMX
resulting in a 204 gram (7.2 ounces) -unit loading, the focused energy of the expansion charged breached the 17.8 centimeter (7 inch) outer diameter pipe. Thu, .to maximize the expansion of this pipe without breaching the pipe would require the amount of explosive energy in.
test #3 to be delivered with less focus.
[0098] Returning to the method discussed above, the relatively short expansion length (e.g.,

10,2 centimeters (4 inches)) may advantageously seal off micro annulus leaks or cure the other cement defects :discussed herein, It may he the case that the cement density between the outer diameter of the inner tubular Ti and the inner diameter of the outer tubular 12 was inadequate to begin with, such that a barrier may not be formed and/or the cement "C"
present between the inner tubular TI and the outer tubular T2 may simply be forced above and below the. expanded protrusion "P" (see, e49 Fig, 2C), While there may still he a senti compression "SC,' of the cement and reduction in porosity, it Might not be adequate to: slow a micro annulus leak in a manner that would contbrm to industry and/or regulatory standards.
in such a case, instead of detonating just one explosive unit 60, multiple explosive units 60 may be detonated, sequentially and in close proximity to each other, or simultaneously and in close proximity to each other, For example, if two explosive units 60 were detonated Sequentially or simultaneously, 10.16 centimeters (4,0 inches) apart in a *one where there is an inadequate cement job, the compression effect of the cement from the first explosive unit 60 being faced down,. and from the second explosive unit 60 being forced up, may result in an adequate harrier ''CB", as shown in fig, 21), that conforms to industry and/or regulatory standards. An example of a shaped charge tool 10 comprising a top sub 12: and haying two explosive units 60 positioned, e.g:, 10,16 centimeters (.40 inches), apart from each other is shown in Fig, 2g.
[0099] Furthermore, three explosive units 60 may be detonated as follows. To begirt with, first and second explosive units 60 may be detonated 20,3 centimeters (8 inches) apart from each other to create two spaced apart protrusions "P;" as shown in Fig. 2E.
The two detonations form two barriers "8" shown in FiOr, 2E, with the first explosive unit 60 forcing the cement ''C" downward and the second explosive unit 60 fOrring cement "C"
upward.
third explosive unit 60 is then detonated between the first and second explosive hints 60.
Detonation of the third explosive unit 60 further compresses the cement "C!' that was forced downward by the first explosive unit 60 and the cement "C" that was forced upward by the second explosive unit 60, to form two adequate barriers 'CB" as Shown in Fig.

Alternatively, detonation of the third explosive unit 60 may result on one battier above or below the third explosive unit 60 depending on the cement competence in the respective zones. Either scenariO tone or two barriers) may further restrict/seal off micro annulus leaks, or cure the other cement defects discussed herein, to conform with industry and/or regulatory standards An example of a shaped charge tool 10 comprising a top sub 12 and having three explosive units 60 positioned, 04., 10.16 centimeters (40 inch*, apart from each other is shown in Fig, 21i, 00] FIGS. 2G and 214 illustrate an embodiment in which =a detonation cord 61 for initiating the tool is run through the length of the tool 10. Another way to configure the detonation cord 61 is to install separate Sections of detonation cords 61 between boosters 61a, as shown in FM. 21_ Each booster 61a eau be filled with explosive material 61b, such as=
184X, That is, a first booster 61a, provided with a first explosive unit 60, may be associated with a first section of detonation cord 61, which first section of detonation cord 61connects to a second booster 61a located further down the tool 10 and provided with a second explosive unit 60. A second section of detonation cord 61 is provided between the second booster 61a and a third booster 61a, as shown in FIG. 21 If further explosive units 60 are provided, the sequence of a section of detonation cord 61 between consecutive boosters 61a may be continued.
[0101] The contingencies discussed with respect to Figs_ 2C through 2F may address the situation in which, even when cement bond logs suggest a cement column is competent in a particular zone, there may still be a variation in the cement volume and density in that zone requirement is more than one expansion charge.
[0102] In the methods discussed above, expansion of the inner tubular Ti causes the sealant displaced by the expansion to compress, reducing the number of micro pores in the cement or the number of other cement defects discussed herein. The expansion may occur after the sealant is pumped into the annulus "A". Alternatively, the cement c:ir other sealant may be provided in the annulus "A" on the portion of the wall of the inner tubular TI, after the portion of the wall is expanded. The methods may include selectively expanding the inner tubular Ti at a second location spaced from the first location to create a pocket between the first and second locations. The sealant may be provided in the annulus "A"
before the pocket is formed. In an alternative embodiment, expansion at the first location may occur before the sealant i .r 1ded, and expansion at the second location may occur after the sealant is provided.
[0103] FIGS. 23 to 2L illustrate methods of selectively expanding at least a =portion of the wall of a tubular surround by formation (earth). FIG. 2J shows that the tool 10 is positioned within the tubular Ti that is cemented into a formation that includes shale strata and sandstone strata. The cement "C" abuts the outer surface of the tubular TIon one side, and abuts the strata on the opposite side, as shown in FIG. 2J. Shale is one of the more non-pprineubte earthen materials, and may be referred rO.as. a cap rock fOrniatioti To the contrary, Sandstone is known. to he permeable. Accordingly, When the tool =i 0 iS used to in a tubular/earth application to consolidate cement adjacent a formation, such: as shown in FIG.

11, it is preferable to expand the wall of the tubular Ti that is adjacent the cap rock formation (e.g., Shale strata)= because the non-permeable cap rock fbrmation seals off the annulus flow, as shown in fia 2K. On the other hand, if the tool 10 was used to expand the wall of the tubular T1 that was adjacent the sandstone strata, as shown in FIG. 2L, even if the cement "C" is consolidated to seal against annulus flow through the consolidated cement "C", annulus flow can bypass the consolidated Cement "C" and migrate or flow through the permeable Sandstone strata (See FIG. 2L), defeating the objective of expanding a wail of the tubular T
[0104] FIGS, 2M and 2N illustrate a method of selectively expanding the walls of two concentric tubulars TI and 12 according to an embodiment. FIG. 2M shows an inner tubular Ti surrounded by an outer tubular T2, and an annulus between the inner tubular TI and the outer tubular T2 that includes a seal*, such as cement "C". A third tubular T1, or ft-yrgoopn, surrounds the outer tubular 12. The annulus between the outer tubular T2 and the third tubular 13 Of formation also includes a sealantõ such as cement `4C2". In the embodiment, annulus flow 'V may be present through in the cement "C" and ".C.2" in both annuli. A tool 10, such as discussed herein, May be positioned within the inner tubular TI
(see FIG. 2N) to selectively expand the. walls of both tubulan TI and T2 with a single actuation of the tool l().
That is, detonation Of the explosive material in the tool 10 creates a force that travels radially outward to impact the inner tubular Ti and expand at least a portion of the wall of the inner tubular T1 radially outward without perforating or cutting through the portion of the wall, to form a protrusion '1?" of the inner tubular TI as shown in FIG. 23+:1, The tool 10 may contain an amount of explosive material based at least in part on a hydrostatic pressure bearing on one or more of the inner tubular Ti. the outer tubular 717, and the tool 10 itself. The protrusion "P" extends into the annulus between the inner tubular TI and the outer tubular 12 to compress the cement "C" to reduce the porosity of the cement "C" by reducing the number of pores, channels, or other cement imperfections allowing annulus leaks. The compressed cement is shown in FIG, 2N with the label "CC". Additionally, the radially traveling force Of the detonated explosive material, and/pr expat4ion of the protrusion 'I)", iinpacts the outer tubular 12 and expands at least a portion of the wall of the outer tubular 12 radially outward without perforating or cutting through the portion of the wall, to tbrm a protrusioil "P2' of the outer tubular T.2õ as shown in FIG. 2N, The protrusion extends int.e the annulus between the outer tubular T2 and the third tubular 13, or formation, to compresses the cement "CC2" in that annulus. The compression reduces the porosity of the Cement "Ccr by reducing the number of pores, ehannels, or other cement imperfections allowing annulus lea.lta, Thus, compressed cement "CC", "cc2" is consolidated M both annuli with one detonation of the explosive material contained in the tool 10. In the embodiment of ElQ.
a single charge is used to form the protrusions "P", "Pr. However, multiple charges, serially oriented in the tool 10, could also be used to form multiple sets of the concentric protrusions .."13"õ "P2" along the axis of the welibore..
[0105] The reduced munber of poreS, channelS, Or other =cement imperfections allowing annulus leaks in the compressed cement "CC', "cc2" reduces the risk of seepage into the cement and helps seal against annulus flow through the consolidated cement.
Further, the protrusions "P", "P2" may create a ledge or barrier that helps seal that partion of the wellbore from seepage of outside materials. The size and shape of the protrusions "P", 'P2" May vary depending on several factors, including-, but not limited ta, the Size ..(04., thickness), strength and material of the inner and outer tubulars TI. TZ the type and amount of the explosive material, the hydrostatic pressure bearing on the inner and otter tubulara Ti.
T2õ the desired size of the protrusions "P", "P2", and the nature of the wellbore operation, [01061 A variation of the tool 10 is illustrated in FK37,. 4, In this embodiment, the axial aperture 80 in the thrust disc 46 is tapered with a conically convergent diameter from the disc face proximate of the detonator 31 to the central aperture 62: The thrust disc aperture $0 may have a taper angle of about 10 degrees between an approximately 0õ2 centimeters (0.08 inches) inner diameter to an approximately 0.32 centimeters (0,13 inches) diameter outer diameter. the taper angle, also characterized as the included angle, is the angle measured between diametrically opposite conical surfaces in a plane that includes the conical axis 13.
[01071 Original initiation of the FIG, 4 charge 60 occurs a the outer plane of the tapered aperture 80 haying a proximity to a detonator 31 that enables/enhances initiation of the charge 60 and the concentration of the resulting explosive force. The initiation shod. wave :propagates inwardly along the tapered aperture 80 toward the explosive junction plane 64. As the shock wave progresses axially along the. aperture 80, the concentration of Onnk, wave energy intensifies due to the progressively increased confinement and concentration of the explosive :energy. Consequently, the detonator shock wave strikes the charge units 60 at the inner juncture plane 64 with an amplified impact. Comparatively* the same explosive charge units 00, as suggested for FIG, 1 comprising, for example, approximately 38.8 grams (1.4 ounces) of 1-1MX compressed under a loading pressure of about 20.7 Mpa (3,000 psi) and when placed in the FIG. 4 embodiment, may require only a relatively small detonator 3.1 of HMX far detonation:. Significantly, the. conically tapered aperture 80 of FIG.
4 appears th fdcus the detonator energy to the central aperture 62,, thereby igniting a given charge with much less source energy. in FIG& 1 and 4, the detonator 31 emits a detonation wave of energy that is reflected (bounce-back of the shock wave) off the flat internal end-face :33 of the integral end wall 32 of the housing 20 thereby amplifying a focused concentration of detonation energy in the central aperture 62 Because the tapered aperture $0 in the FIG. 4 embodiment reduces the volume available for the detonation wwvc, the concentration. of detonation energy becomes amplified relative to the FIG. 1 embodiment that does not include the tapered aperture 80_ [019$1 The yariation of the it)04 10 shown in fIG 5 !.e0:0,5 upon in open, 4tbstantially cylindrical aperture 47 in the upper thrust disc 46 as Shown the FIG. I embodiment.
HoweVer, either no Vernet is provided in the end plate boss 72 of FIG. 5 Or the aperture 49 in the lower end plate 48 is filled with a dense, metallic. plug 76, as shown in FIG. 5. The plug 76 may be inserted in the aperture 49 upon final assembly or pressed into place beforehand.
As in the case of the Fici. 4 embodiment, the FIG% 5 tool 10 comprising, for example, approximately 38,8 grams (1.4 ounces) of FIMX compressed under a loading pressure of about 20.7 Mpa (3,000 psi), also may require only a relatively small detonator 31 of HIVIX for detonation. The detonation wave emitted by the detonator 31 is reflected back upon itself in.
the central aperture 62 by the plug 76, thereby amplifying a focused concentration of detonation energy in the central aperture 62.
[01091 The FIG-. 6 variation of the tool 10 combines the energy concentrating features of FIG. 2 and FIG 5, and adds a relatively striall, explosive initiation pellet 66 in the central aperture 62. In this case, the detonation wave of energy emitted from the detonator 31 is reflected off of explosive initiation pellet 66. The reflection from the off of explosive initiation pellet 66 is closer to the juncture plane 64, which results in a greatcT concentration of energy (enhanced explosive force). The explosive initiation pellet 06 concept can be applied to the FIG. 1 embodiment, also.

[0110] Transporting and storing the explosive units may be hazardous. There are thus safety guidelines and standards governing the transportation and storage of such. One of the ways to mitigate the hazard associated with transporting and storing the explosive units is to divide the tants into Waller component pieOes. The smaller component pieces May not pose the same explosive riSlc during transportation and storage as a full-size unit may have. EaCh of the explosive units 60 discussed herein may thus be provided as a set of units that can be transported unassembled, where their physical proximity to each other in the shipping box would prevent mass (sympathetic) detonation if one explosive component was detonated, or 11., in a fire, .1vould burn and .nOt detonate. The set is configured to he easily Skin:bled at the job site, [0111] Fig, 10 shows an exemplaty embodirrient of a set 100 of explosive units.
Embodiments of the explosiVe units disCussed herein may be configured as the set 100 discussed below. The set 100 comprises a first explosive unit 102 and a second explosive unit 104, Each of he first explosive. unit 'Or and the Second explosive unit 104 comprises the explosive Material discitsSed herein. Each explosive unit 102,, :104 may be frusto-conically shaped, hi this configuration, the first explosive unit 102 includes 0 smaller area first surface 106 and a greater area second surface 110 opposite to the smaller area first surface 106.
Similarly, the second explosive unit 104 includes a smaller area first surface 108 and a greaor area second surface 112 opposite to the smaller area first surface 108.
Each of the first exploSiye unit 102 and the second explosive unit 104 may be s).nunetric about a longitudinal axis 114 extending through the units, as shown in the perspective view of FIG.
11. Each of the first explosive unit 102 and the second explosive unit 104 comprises a center portion 120 having an aperture 122 that extends through the center portion 120 along- the longitudinal axis 114, [01121 in the illustrated embodiment, the smaller area firSt snrfue 106 Of the first explosive unit 1.02 includes a recess 116, and the smaller area first surface 108 of the second :explosive unit 104 comprises a protrusion 118. The first explosive unit 102 and the second explosive unit 104 are configured to he connected together with the smaller atea first surface 106 of the first explosive unit 102 Wog the second explosive unit 104, and the smaller area first surface 108 of the seeptict explosive unit 104 facing the smaller area first surface 106 of the first explosive unit 102. The protrusion 118 of the second explosive unit 104 fits into the recess 116 of the first ep1oe unit 102 to j(.8in the first explosive unit 102 and the second explosive Unit i 04 together, The first kplosiVe unit 102 and the second exploSive unit 104 can thus be easily connected together without using tools or other materials, [01131 In the ernbodiment, the protrusion 118 and the recess 116 have a circular shape in planform, as shown in Figs. 11 and 1/n other embodiments, the promision 118 and the recess 116 may !lave a different shape. For instance, Fig, 13 shows that the shape of the protrusion 118 is square. The corresponding recess (not shown) on the other explosive unit in this embodiment is also square to fitably accommodate the protrusion 118.
Alternative shapes for the protrusion 118 and the recess 116 may be triangular, rectangular, pentagonal, hexagonal, oetagonal or other polygonal shape having more than two sides.
[01141 Referring back to FIG. 10, the set 100 of explosive units can include a first explosive sub unit 202 and a second explosive sub unit 204. The first explosive sub unit 202 is configured to be connected to the first explosive unit 102, and the second explosive sub unit 204 is configure4 to be connetted to the second explosive wiit 104, as discussed below.
Similar to the first and second explosive units 102, 104 diseussed above, each of the first &plosive sub unit 202 and the second explosive sub unit 204 can be frusto-conical so that the sub units define smaller area first surfaces 206, 208 and greater area second surfaces 210, 212 opposite to the smaller area first surfaces 206, 208, shown in FIG. 10.
[01151 In the embodiment shown in FIG. 10, the larger area second surface 110 of the fifSt explosive unit 102 includes a first projection 218, and the smaller area first surface 206 of the first explosive sub unit 202 includes a first cavity or recessed area 216. The first projection 218 fits into the first cavity or recessed area 216 to join the first explosive twit 102 and the first explosive sub unit 202 together. Of course, instead of having the first pro iection 218 on the first explosive unit 102 and the first cavity ot recessed area 216 on the first explosive sub unit 202, the first projection 218 may be provided on the smaller area first surface 206 of the first explosive sub unit 202 and the first cavity 216 may be provided on the larger area second surface 110 of the first explosive unit 102, [01161 Ftp, 1.0 4140 shows: that the larger area second surface 112 of the second exploSive unit 104 comprises a first cavity or rocgs&i: area 220, and the smaller area first surface 20$ of the second explosive sub unit 204 comprises a first projection 222. The first projection 222 fits into the Opt cavity or recessed area 220 to jOin the second explative unit 102 and the second explotiVe tub unit 204 together: Of cotitte, instead of having the first projection 222 on the second explosive sub unit 204 and the first cavity 220 on the second explosive unit 104, the first projection .222 may be provided on the larger area second surface 112 of the seeOpd explosive unit 104 and the first oviti,,-22o may be provided on the smaller area first surface 208 of the. second explosive sub unit 204. The first and second explosive sub units 202, 204 may also include the aperture 122 extending along the longitudinal axis 114.
[0117] FIGS. 10 and 11 show that the first explosive unit 102 includes a side surface 103 connecting the stnaller area first surface 196 and the greater area second surface 110.
Similarly, the second explosive unit 104 includes a side Stirface 105 connecting the Sinaller area first surface 108 and the greater area second surface 112. EaCh side surface 193, 105 may consist of only the explosive material, so that the explosive material is exposed at the side surfaces 103, 105, In other words, the liner that is conventionally applied to the explosive nnits is absent from the first and second explosive units 102, 104.
The side surfaces 107, 109 of the first and second explosive nib units 292, 204, respectively., can. consist of only tho explosive material, so that the explosive material is: exposed at the side surfaces 107, 109, and the liner is absent from the first and second explosive sub units 202, 204.
[01181 Figs, 14-17 illustrate another embodiment of an explosive unit 300 that may be included M a sot of several similar units 300. The explosive twit 300 may be positioned in =a tool 10 at a lOcatiOn and orientation that is opposite a similar explosive unit 300, in the same manner as the explosive material units 60 in Figs. 1 and 4-6 discussed herein, Fig, 14 is a plan view of the explosive unit 300, Fig. 15 is =a plan view of one segment 302 of the explosive unit 300, and Fig, 16 is a side view thereof. Fig, 17 is .a cross,sectional side view of Fig. 13. In the embodiment, the explosive unit 300 is in the shape of a frustoconical disc that is formed of three equally-sized segments 391, 302, and 303. The explosive unit 300 may include a central opening 304, as .shown in Fig. 14, for accOnimodating the Shaft of an explosive booster (hot shown). The illustrated embodiment Shows that the explosive unit 300 is ibrmed of three segments 301, 302, and 303 each accounting for one third (i.e, 120 degrees) of the entire explosive unit 300 (i.e, 360 degrees). However, the explosive unit 300 is not limited to this embodiment, and may include two senents or four or more segments depending nature of the explosive: material forming segments. FOr instance, a more highly explosive material may require a greater number of (smaller) segments in order to comply with incinstqt regulations for safely transporting explosive material, For instance, the explosive unit 300 may be formed of four segrnentS, each aecounting :for One quartet (i.e., 90 degrees) of the entire explosive unit 300 (ie., 360 degrees); or may be formed of six segments, each accounting for one sixth (Le, 60 degrees) of the entire explosive unit 300 3.60 degrees). According to one entbodimetn, each segment 'should include nO
mine than 38$ grains (1.4 ounces) of explosive material.
[0119] In one embodiment, the explosive unit 300 may have a diameter of about 8.38 centimeters (3.3 inches). Figs, 15 and 16 Show that the Segment 302 has a top surface 305 and a bottom portion 306 having a side wall 307. The top surface 305 may be slanted an angle Of 17 degre0 from the central opening 304 to the Side wall 307 in an embodiment.
According, to one ernbodiment, the overall height of the segment 307 may be about 1.905 centimeters (0.75 inches), With the Side wall 307 being about 0,508 Centimeters (0,2 inches) of the overall height. The overall length of the segment 302 may be about 7.24 centimeters (2,5 inches) in the embodiment. Fig. 17 Shows that the inner bottom surface 308 of the segment 302 may be inclined: at 4i angle of 12 degreo,, 4ceording to one embodiment The width of the bottom portion 306 may be about 1:37 centimeters: (0.54 inches) according to an embodiment with respect to Fig. 17. The side wall 309 of the Central opening 304 may have a height of about 0,356 centimeters (0.14 inches) in an embodiment, and the uppermost part =310 of the segment 302 may have a width of the about 0,381 centimeters (0.15 inches), The above dimensions are not limiting, as the segment size and number may be different in other emboditnerits. A different segment sizee andior number may have different dimensions. The explosive units 300 may be provided as a set of units divided into segments, so that the explosive units :300 can be transported as unassembled segments 301, 302, 303, as discussed above.
[01201 The set of segments is configured to be easily assembled at the job site. Thus, a method of selectively expanding at least 4 portion of a wall of a tubular at a well site via 4 shaped charge tool 10 may include first receiving an unassembled set of explosive units 300 at the well site, wherein each explosive unit 300 comprising explosive material, is divided multiple segments 301, 302, 30:3 that, when joined together, form an explosive unit 300, The.
method includes assembling the 001 10 (see, e.gõ I) comprising a shaped charge assent* Comprising a housing 20 and two end plates 44, 48. The housing 20 comprises an inner surface 51 racing tln interior of the housing 20. At the well site, the segments 301, 302, 303 of each explosive unit 300 are together to form the asserohled explosive unit 300., The expIOSive units 300 are then positioned between the two end plates 46, 48, fa instance each explosive unit 300 is adjacent one of the end plates 46, 48, so that an exterior surface of the explosive material of explosive units 300 faces the inner surface 51 of the housing 20. In an enibodiment, the explosive material is expos0 to the inner surface 51 of the housing 20.
Next, a detonator 31 is positioned adjacent to one of the two cod plates 46, 48, and the shaped charge tool 10 is positioned within the tubular. The detonator 31 is then actuated to ignite the explosive material causing a shock wave that travels radially outward to impact the tubular at a first location and expand at least a portion of the wall of the tubular radially outward without perfOrating or cutting through the portion of the wall, to form a protrusion of the tubular at the portion of the wall. The prottusion extends into an annulus between an outer surface of the wall of the tubular and an inner surface of :a wall of another tubular or a formation.
[01121] FIGS, IS - 22 Show embodiments of a centralizer assembly that. may be attached to the housing 2Ø The centtor40 assembly centrally confines the toijl 10 within the inner tubular IL in the embodiment shown in Fig. 1:8,= plan-from view of the centralizer assembly is shown in relation to the longitudinal axis 13. The tool 10 is centralized by a pair Of substantially circular centralizing discs 316. Each of the centralizing discs 3.1.6 are secured to the housing 20 by individual anchor pin fasteners 318, such as screws or.
rivets. In the FIG. 18 embodiment, the discs 316 are mounted along a diameter line 320 across the housing 7Ø, Ny4h the most distant points on the disc perimeters separated by a dimension that is preferably at least corresponding to the inside diameter of the inner tubular Ti. in many eases, however, it will be desirable to have a disc perimeter separation slightly greater than the internal diameter of the inner tubular IL
[01221 In another embodiment shown by FIG, 19. each of the three discs 316 are. secured by Separate pin fasteners 318 to the housing 20 at approximately 120 degree arcuate spacing about the longitudinal axis 13. This' configuration is representative Of applications fbt, multiplicity of centering discs on the housing 20. Depending on the relative sizes of the tool and the inner tubular Ti, there may be three or more such discs distributed at substantially uniform arcs about the tool circumference, 1.01:31 FIG, 20 shows, in planform, :another embodiment of the centralizers that includes Spring steel centralizing wires 330 of small gage diameter: .A plurality of these wires is arranged radially from an end boss 332. The wires 330 can be formed of high-carbon steel, stainless steel, or any metallic or metallit composite matedal with sufficient flexibility and tensile strength. While the embodiment includes a total of eight centralizing wires 330, it Should be appreciated that the plurality may be made up of any number of centraliling wires 330, or in some cases, as few as two. The use of centralizing wires 330 rather than blades or other machined pieces, allows for the advantageous maximization of space in the flowbore around the centralizing system, compared to previous spider-type centralizers, by minimizing the crosS-seetion compared to systems featuring flat blades or other planar configurations. The wires 330 are oriented petpendicular to the longitudinal ax:is 13 and engaged with the sides of the inner tubular, which is 'positioned within an outer tubular T2;
The wires 330 may be sized with a length to exert a compressive force to the tool 10, and flex in the same fashion as the cross-section of discs 316 during insertion and withdrawal.
[0124) Another embodiment of the centralizer assembly is Shown in El(1, 21, This configuratiOn comprises a plurality of Omar blades 345a, 345b to centralize the 001 10, The blades 345a, 345b ate positioned cm the bottom surface of the tool 10 via a plurality of fasteners 342. The blades: 345a, 345b thus flex against the sides of the inner tubular T I to exert a centralizing force in substantially the same fashion as the disc embodiments discussed above. F10õ 18 illustrates an embodiment of a single blade 345. The blade 345 comprises a.
plurality of attachment points 344a, 344b, through which fasteners 342 seCiite the blade 345 in position, Each fastener 342 can extend through a respective attachment point to secure the blade 345 into position. While the embodiment in FIG, 21 is depicted with two blades 345a, 345b, and each blade 345 coraptises two attachment points, for a total of four fasteners 342 and four attachment points (344a, 344b are pictured in HO. 22), it should be appreciated that the centralizer assembly may cOmprise any number of fastenets and attachment points.
[01251 The multiple attachment points 344a, 344b on each had .345, being spaced laterally from cattl.. other, prevent the unintentional rotation of individual blades 345, even in the event that the fasteners 342 arc slighdy loose from the attachment points 344a, 344b, The fasteners 342 on be. of .aoy tyo of fastener usable f;Or securing the blades into position, including screws. The blades 345 cat be spaced laterally and oriented perpendicular to each other, ft)r centralizing the tool 1.0 and preventing unintentional rotation of the one or more blades 345.

[0126] While the disclosure abaft discusses embodiments in which there is no liner on the exterior surface 50 of the explosive units 60 (ix, the exterior surface 50 of the explosive units 60 is exposed to the inner surface 51 of the housing 20), alternative embodiments of the present disclosure may inchule a litlet 50a on the exterior surface of the explosive units 60, as oiowp in na 24, and may be able to achieve similar results as the liner-less explosive units 60 according to the following criteria. Conventionally9 liners for explosive units were formed of material with relatively high density and ductility so that, when collapsed by a detonation wave of the ignited explosive units, the liners form a jet that is strong enough to penetrate the pipe or tubular in a cutting or perforating operation. Conventional materials for such liners intluded topper, nickel, zinc, zinc alloy, irOrt, 0, bismuth, and tungsten.
[0127] On the other hand, a lina formed of a relatively tow density and brittle material would not jet as well as the conventional materials discussed above The present inventor has determined that a formed of a material that is less dense and ductile than copper, nickel, zinc, 4ine alloy, iron, tin, bismuth, and tungsten, individually or in conibinatjon, (i.e., formed of a material that is brittle and has law density), may be effective in expanding, without puncturing, the wall of the tubular TI to form the protrusion "P' discussed herein. in this regard, an enibodiment of the liner 50a may have a density of 6 gice or less, and may be less ductal than copper, nickel, zinc, :zinc alloy, iron, tin, bismuth, and tungsten, individually or in combination. In an embodiment the liner 506. may be :formed of glass material.
In another emboditnent, the liner 50a may be formed of a plastic material.
[0.128] Another way to reduce the potency of the liner jet, so that the jet may expand, without puncturing, the wall of the tubular TI to form the protrusion "P" discussed herein, is to perforate the liner 50a. In addition, or in the alternative, the liner 50a may be formed so that a density, w,all thickness, and/or :composition of the liner 50a is asymmetric around at least one of the explosive units 60. Itt addition, or in the alternative, the explosive units 60 may be formed so that a density, wan thickness, and/or composition of the explosive units 60 is asymmetric around at least one of the explosive units 60õ Further, the liner 50a of at least one of the explosive units 60 may be geometrically asymmetric. Asymmetric explosive units 60 may reduce the potency of explosive units 60 so that detonation of the explosive nnits 60 may expand, without puncturing, the w411 of the tubular TI to for, the protrusion discussed herein, Similarly, asymmetric liners may reduce the potency of the jet formed by the liners, so that the jet may expand, without puncturing, the wall of the tubular T) to form the protrusion "P"diScuSSed herein.
[0129] FIG. 25 illustrates another embodiment of a tool 10 for selectively expanding at least a portion Of a Wall of a tubular. The tOC4 10 in this embodiment coMpriseS a liner 50e on the outer surface of the explosive units 60. The liner 50c :may be a liner fermed of the conventional materials discussed above (e.g., copper, nickel, zinc, zinc alloy, iron, tin, bismuth, and tungsten). The tool 10 further comprises an extraneous object 55 located between the inner surface of the housing 20 and the liner 50c. The extraneous object 55 fouls the jet tbrined by the liner 500 so that the jet expands. Without puncturing, a: portiOn of the wall of the tubular T1 to form a protrusion 1=1" extending outward into an annulus; adjacent the wall of the tubular TI, as discussed herein. The extraneous object 55 may he one of a foam object, a rubber object, a wood object, and a liquid object, among other thing&
[01301 NG& 26A-26D illustrate a method of reducing a leak 505, such as a micro annulus leak as discussed herein, in an annulus 50; adjacent a tubular 501 in a well:bat* 509. "Me method may also be implemented, for example, in a plug-and-abandonment operation. FIG.
26A Shows an example of a wellbote 500 that includes an annulus 502 disposed between an inner tubular 501 and an outer tubular, or formation, 504. The tubular 501 may be the same or akin to the tubular(s) discussed herein. The annulus 502 may contain a sealant 503, Such as cement, A leak 505 may exist in the annulus 502: The leak 505 may be an oil leak, a gas leak, era combination thereof: The method may begin with setting a plug 506 41 a location within the tubular 501 as shown in FIG. 26B to prevent fluidõ gases, and/or other wellbore materials from traveling up the tubular 501 past the plug 506. The plug 506 may be a cast iron bridge plug, a cement plug, or any plug Which isolates the lower portion of the well from the upper portion of the welt The plug 506 may also be used to seal the tubular 501 andlor provide a stop for a sealant, such as :cement, that may be pumped into the annulus 502 from the tubular 501 in the folloWing manner. One or More puncher charges (not shown) 'frilly be inserted into the tubular 501 and actuated to punch holes 507 in the wall of the tubular 501 at a location uphole of the plug 506, as Shown in F1Q, 26C. The puncher charges may be any commercially available shaped charges that when detonated, form a jet of limited length to "punch" a hole in the target pipe without damaging any member beyond the target pipe, The holes 507 can serve as passages for a sealant; such as cement, that can be subsequently pumped, or otherwise providedõ into the tubular 501 and squeezed through the holes 507 int) the annulus 502, As Shown in Fig. 260, the sealant (e ;:gõ. content) is squeezed through the holes 507 and into the annuins 502 to densify the sealant (sec densified sealant 508) that is already present in the annulus 502, or otherwise to fill the annulus 502, for sealing or reducing the leak 505. By sOme estimates, the method of reducing the leak 505 in the annulus 502, as discnssed with respect to FIcil$: 26A to 261).. may be only 35%
:successful, [01311 A more successful method of reducing a leak 505 in the annulus 502, adjacent a tubular 501 in a wellbore 500, is shown in FIGS. 27A to 27E. FIG. 27A
illustrates a scenario, as discussed above, in which a leak 505 exists in the annulus 502 adjacent a tubular 501 in a wellbore 500. As before, a plug 506 may be set at a location within the tubular 501, as shown FIG. 27B. The plug 506 may be the sante its the plug 506 discussed above, Next an expansion tool 509, containing an amount of explosive material, is insetted into the thbular 501 uphole of the plug 506 as shown in FIG. 27C. The expansion tool 509 may be any one of the expansion tools and their variations as discussed herein, The explosive material may be any of the explosive materials discussed herein or other HMX., RDX or ENS
material. Other characteristies of the tubular andlor the welibore may also be determined and*
accounte.d for, as discussed above, as necessary or as desired to determine the amount of explosive Material in the expansion tool 509. The amount of explosive material in the expansion tool 509 may be based at least in part on a hydrostatic pressute bearing on the tubular 501 in the Vvellbore 500, as discussed herein. The amount of explosive material produces an explosive force sufficient to expand, without puncturing, the wall of the tubular 501.
The expansion tool 509 may then be actuated to expand the wall of the tubular 501 radially outward, Without perforating or cutting through the wall of the tubular 501 to form one or more protrusions 510 as shown in HQ, 27C, Each protrusion 510 extends into the annulus 502 adjacent an outer surface of the wall of the tubular 501, in the manner(s) discussed herein. The protrusions 510 may seal oft or inay help seal off; the annulus 502 by protruding toward or against the outer pipe 504 (or formation) surrounding the annulus 502. For instance., FIG, 27C Shows that the protrusions 510 may densify the sealant (see densified sealant 508) already present in the annulus 502, or otherwise fill the annulus 502, to seal or reduce the leak 505. The protrusions 510 may seal off, or may help seal off, the annulus 502 against leaks in the sealant 503 by compressing any voids in the sealant 503 and/or collapsing open channels in a cemented annulus 502. In :some cases, the protrusions 510 extending into the annulus may be enough to provide an acceptable seat against the leak 505 Moving uphole beyond the protrusions 510, and no further remedial action may be required. By some estimates, the manner (yf reducing the leak 505 in. the annulus 502 as discussed with respect to FIGS. 27A to 27C May be at least 70% suceesSful, To increase the success rate, if needed, additional steps to reduce the leak 505 in the annulus 502 are shown in FIGS, 27D and 27E, [01321 In particular, one or more puncher charges (not shown) may be subsequently inserted into the tubular 501 and actuated to punch holes 507 in the wan of the tubular 501 as shown in FIG. 27Ø The puncher charges may be the same as those discussed above, As discussed above; the boles 507 serve as passages for a sealant, such as cement, to subsequently be pumped, or otherwise provided, into the tubular $01 and squeezed through the boles 507 into the annulus 502, at least down to the upper protrusion 510. As shown in FIG.
:27E, the sealant colon) can be Sqiieted through the holes 507 into the annuhiS 502 to densify the sealant (see densified sealant 508) already present in the annulus 502, or otherwise to till the annulus 502, for sealing or reducing the leak 505, at least down to the upper protrusion 510.
In some cases, however, the cement squeezed through the holes 507 may travel down beyond the upper protrusion 510 if any voids or channels in the densifted sealant 508 are large enough to permit such flow, In addition, the protrusions 510 may fotm a restriction or a ledge below where the cement 507 will be introduced into the annulus 502. If the sealant is viscous enough, the protrusion 510 may provide the annulus seal by itseif By Some estimates, the method of reducing the leak 505 in the annulus 502 as discussed with respect to HOS. 27D
and 27E niav be at kaSt 90% successful, [0113] In the embodiments discussed above expansion tools including one or more expansion charges have been discussed. The expansion charges may be shaped charges as discussed abovev liowever, a dual end firing tool or single end firing tool may also be used to expand, without puncturing, the wall of the tubular to form a protrusion extending outward into the annulus adjacent the wall of the tubular as discussed herein. Dual end fired and single end fired cylindrical CxplosiVe Column tools (e.g., modified prossot balanced or pressure bearing severing tools) produce .a focused energetic 'reaction, but with unich less: focus than from shaped charge expanders. In dual end fired explosive column was, the focus is achieved via the dual end firing of the explosive column, in which the two explosive wave fronts collide in a middle part of the column, amplif*g the pressure radially.
In single end fired explosive column tools, the focus is achieved 0.4 the firing of the explosive column from one end which generates QM wave front producing comparatively less energy. The single wave front May form a protrusion in the wall of the tubular, without perforating or cutting through the wall. The prO03410 formed by a single end fired exp104ive Column ool may be asymmetric as compared With a protrusion formed by a dual end fired explOSive column tool. The length of the selective expansion in both types of explosive column tools is a function of the length of the explosive column, and may generally be about two times the length of the explosive Column. With a relatively longer expansion length, for example, 40.64 centimeters (16.0 inches) as compared to a 10.16 centimeter (4.0 inch) expansion length with a shaped charge explosive device, a much more gradual expansion is realized.
The more gradual expansion allows a greater expansion of any tubular or pipe prior to exceeding the elastic strength of the tubular or pipe, and failure of the tubular or pipe (1,e,, the tubular or pipe being breeched),.
[0:1.341 An embodiment of an expansion tool 600 for selectively expanding at least a portion of a wall of a tubular is shown in FIGS. 28.,30, The expansito tool 600, as shown in this embodiment, is a dual end firing explosive column tool, and can be used for applications involving relatively large and thicker tubulars, such as pipes having a 6,4 centimeter (23 inch) %kid thickness, an inner diameter of 77,9 centiinetets (9,0 inches) or more and an outer diameter of 35,6 centimeters (14.0 inches) or more. However, the dual end firing explosive column tool 600 is not limited ti) use With such larger tubularS, and ratty effectively be used to expand the wall of smaller diameter tubtdars and tubulars with thinner walls than discussed.
above, or with larger diameter tubulars and tubuiars with dikter walls than discussed above.
[013fl FIQ; 2$ Shows a cross..k..,(.1ional view of an embodiment of the dual end firing explosive column tool 600. In this embodiment, the dual end firing explosive column tool 1500 is a modified pressure balanced tool. FIGS. 29 and :30 show details of particular portionS
of the dual end firing explosive column tool 600. As shown, the dual end firing explosive column tool 600 can include a top sub 612 at a proximal end thereof. An internal cavity 613 M the top sub 612 can be termed to receive a firing bead (not shown): A guide tube 616 can be sectued to the top sub 612 to project from an inside face 03$ of the top sub 612 along an axis Of the tool 600, The opposite distal end of guide tube 616 can suppOrt a guide tube terminal 618, which can be shaped as a disc. A threaded boss 619 can secure the terminal 618 to the guide tube 616. One or MOM resilient spactra 642; such as silicon foam washers, can be positioned to encompass the guide tube 616 and beat against the upper face of the terminal 618.

101361 'the dual end firing explosive column WO 600 can be arranged to serially align a plurality of high OtplOsiVe pellets 640 along a central tube to fortn an explosive column. The pellets 640 may be pressed at forces to keep well fluid from migtating into the pellets 640. In addition, or in the alternative, the pellets 640 may be coated or sealed with glyptal or lacquer, or other tOmpound(s), to prevent well fluid from migrating into the pellets 640, The dual end firing explOsive column tool 600, as shownõ is provided without an exterior housing so that the explosive pellets 640 can be exposed to an outside of the dual end firing explosive column tool 600, meaning that there is no housing of the dual end firing explosive column tool 600 covering the pellets 640, That is, when the dual end firing explosive column tool 600 is inserted into a pipe or other tubular, the: explosive pellets 640 can be exposed to an inner stittliCe of the pipe or other tubular. AlternatiVely, a Sheet of thin material, or ":Cab housing's (opt shown) may be provided with the dual end firing explosive column tool 600 m cover the pellets 640, for protecting the explosive material during running into the well. The material of the "scab housing" can be thin enough so that its effect on the explosive impact of the pellets 640 on the surface of the pipe or other tubular is immaterial. Moreover+ the exploSive force co= vaporize or pulverize the 'scab housing" so that no debris from the: "KO
housing" is. left in the wellbore. some embodiments, the ''.scab housing' may be formed of Teflon, PEEK, ceramic taaterialsõ Or highly heat treated thin metal above 40 Rockwell "C".
131-directional detonation boosters 624, 626 are positioned and connected to detonation cords 630, 63:2 for simultaneous detonation at opposite ends of the explosive column. Each of the pellets 640 can comprise about 22,7 grams (001 ounces) to about 38,8 grams (1.37 ounces) of high order explosive, such as RUN, tiMX r FINS. The pellet density Can be from, e.g.:, about 1.6 glom' (0,92 ortin) to about 1+65 g/cm3 (0.95 az103), to achieve a shock wave velocity greater than about 9,144 meters/sec (30,000 ft/sec), for example.
[0:1:37] A shod( wave of such magnitude can provide a pulse of pressure in the order of 27.6 Gpa (4 x 1.0' psi). It is Me pressure pulse that expands the wall of the tubular_ The pellets 640 can be compacted at a production facility into a cylindrical shape for :serial, juxtaposed loading at the jobsite, as A. column in the dual end firing explosive column tool 600, The dual end firing explosive column tool 600 can be configured to detonate the explosive pellet column at both ends simultaneously, in order to provide a shock front from one end colliding With the shot* front to the opposite end within the pellet eohunn at the center of the column length. On collision, the pressure IS multiplied, at the point of collision, by about:four to five times the normal pressure cited above. To achieVe this result., the Simultaneous firing of the bktirectionai d0Q1latipp bOOSterS 6245 626 can, be timed precisely in order to assure c011isiori within the (*plosive column at the: center. In an alternative embodiment, the expansion tool 600 may be a single end firing explosive column tool that includes a detonation booster at only one end of the explosive pellet column, $0 that the explosive column is detonated from only the one end adjacent the detonation booster, as discussed above, and so the configuration of the single end Ming explosive column tool is similar to that of the dual end firing explosive column tool discussed herein.
[0138] TOward the upper end of the guide tube 616, an adiustably positioned partition disc 620 OM be wined by:a set sCrew 621. Between the parth ion disc .620 and the inside face 638 of the top sub 612 can be a timing Spool 622, as Shcnvti. in FIG 28, A first hi-directiOnal booster 624 can be located inside of the guide tube bore 616 at the proximal end thereof; One end of the first hi-directional booster 624 may abut against a bulkhead formed as an initiation pellet 612a. The first hi-directional booster 624 can have enough explosive material to ensure the requisite energy to breach the bulkhead. The opposite end of the first hi-directional booster 624 can comprise pair of mild detonating cords 610 and 632, which can be secured within detonation proximity to a small quantity of explosive material 62,5 (See RP. 29).
Detonation proximity is that distance between a particular detonator and a particular receptor explosive within which ignition of the detonator will initiate a detonation of the receptor explosive. The detonation cords 630 and 632 can have the same length so as to detonate opposite ends of the explosive column of pellets 640 at the Same time. As shown. in MS. 28 and 30, the first detonating cord 630 can continue along the guide tube 616 bore to be Secured within a third hi-directional booster 626 that can be proximate of the explosive material 627.
A first window aperture 634 in the wall of guide tube 616 can be cut opposite of the third bi-directional booster 626,, as shown. As shown in FIGS, 28 and 29, from the first hi-directional booster 624., the second detonating cord 632 can be threaded through a second window aperture 630 in the upper *A1l of guide tube 616 and around the helical surface channels of the timing spool 622. The timing spobl, which is outside the cylindrical surface, can be helically channeled to receive a winding lay of detonation cord with insulating material separations between adjacent wraps of the cord. The distal end of second detonating cord 632 can terminate in a second hi-directional booster 628 that is set within a.
receptacle in the partition disc 620. The position of the partition disc 620 can be adjustable along the length of the guide tube 616 to accommodate the anticipated number of explosive pellets 640 to be loaded, [0i 39] To load the dual end firing &plosive 'column tool 600, the Ode tube terminal 618 can be removed along with the resilient spacers 642 (See FIG. 30). The pellets 640 of powdered, high explosive -material, such as RDX, MIX or FENS, can be pressed into narrow Wheel shapes. The pellets 649 may he coated/sealed, as disettssed above : A
central aperture can be provided in each pellet 640 to receive the guide tube 616 theretbrough Transportation safety may limit the total weight of explosive in each pellet 640 to, for example, less than 38:8 grams (600 grains) (1.4 ounces). When pressed to a density of about L6 gicm3 (0.92 0494 to about 1,65 gicm3 (0,95 min), the pellet diameter may determine the pellet thickness within a deterMinable limit range.
101401 The pellets 640 can be loaded serially in a column along the guide tube 616 length with the first pellet 640, in juxtaposition against the lower face of partition disc 620 and in detonation proximity with the second bi-directional booster 628. The last pellet 640 most proximate of the terminus 618 is positioned adjacent to the first window aperture 634. The number of pellets 640 loaded into the dual end firing explosive column tool 600 can vary along the length of the tool 600 in order to adjust the sire of the shock WM
that results froth igniting the pellets 640. The length of the guide nibe 616, or of the evlosive column fOrmed by the pellets. may depend on the calculations or testing diScussed below.
Generally, the expansion length of the wall of the tubular can be about two times the length of the column of explosive pellets 640. In testing performed by the inventor, a 19.1 centimeters (7.5 44) column of pellets 640 resulted in an expansion length of the. Wall of a tubular of 406 centimeters (16 incheS) (A, a ratio Of column length to expansion length of I
to 2.13). Any space remaining between the face of the bottom-most pellet 640 and the guide tube terminal 618 due m fabrication tolerance variations may be tilled, with resilient spacers 642, [0141] FIci.S. 31-33 i 1 ustra Le another embodiment of an expansiou tool 600'. The expansion tool 600' in this embodiment iS a modified pressure bearing pellet tool, and differs from the modified pressure balanced pellet toOl of FIGS. 28-30 in that the modified pressiue bearing pellet tool 600' includes a housing-, 610 having an internal bore 611, in which the guide tube 616 and explosive pellets 640 are provided. The internal bore 611 can be seale.d at its lower end by a bottom nose 614. The interior face of the bottom nose 614 can be cushioned with a resilient padding 615, Such as a silicon foam Washer, lin other tespectS, the modified pressure.

bearing pellet tool 60(Y is similar to the modified pressure balanced pellet tool 600, and so like components are similarly labeled in FIGS. 31-31 [01421 A method of selectively expanding at least a portion of the wall of a pipe or other tubular nsing, the expansion tool de4erthed herein: may he as follows The expansion tool may be either the modified pressure balanced tool 600 of FIGS. 28-30, ot the modified pressure bearing tool 600' of FIGS:, 31.,33., The tkpaiistotx tool.i assembled by arranging predetermined number of explosive pellets 640 on the guide tube 616, which can be in a serially-arranged column between the second and third bi-directional boosters 628, 626, so that the explosive pellets 640 are exposed to an outside of the expansion tool. The expansion tool is then positioned within a. tubular TI that is to be expanded, as shown in PIO, 34A, [01431 As shown in Fla 34A9 the tubular Ti May be an inner tubular that is located within an outer tubular 12, such that an annulus "A' is formed between the outer diameter of the inner tubular Ti and the inner diameter of the outer tubular T2. In some cases, the annulus may contain material, such as cement, barite, other sealing materials, mud and/or debris.
in other cases, the annulus "A" may not have any material therein. When the expansion tool OK 600' reaches the desired location in the tubular T1, the hi-directional boosters 624, 626, 628 are detonated to simultaneOtisly ignite opposing ends of the serially-arranged column of pellets 640 to form two shock waves that collide to create an amplified shock wave that travels radially outward to impact the inner tubular TI at a first location, and expand at least a portion of the wall of the tubular TI radially Outward, as shown in FIG. 3413, without perforating or cutting through the portion of the wall, to form a protrusion "'P' of the tubular Ti at the portion of the wail The protrusio11"P" extends into the annulus between an outer surface of the wall of the inner tubular Ti and an inner surface of a wall of the outer tubular T2. Note that the pipe dimensions shown in FIGS. 34.A to 34C are exemplary and for context, and are not limiting to the scope of the invention.
[0144] The protrusion 1)." may impact the inner wall of outer tubular T2 after detonation of the explosive pellets 640. in Some embodiments, the protrW.ion. "P" may maintain contact with the inner wall of the outer tubular T2 after expansion is completed. In other embodiments, there may be a. sinati space between the protrusion. 'II" and the inner wall of the outer tubular .12. Expansion of the tubular T I at the protrusion '1?" can cause that portion of the wall of the., tubular Ti to be work-hardened, resulting in greater strength of the wall at the protrusion "P". Embodiments of the methods of the present illy:ail-ion show that the portion of the wall having, the protrusion "P" is not we4ened in particular, the yield strength of the tubular 11 increases at the protrusion "P", while the tensile strength of the tubular TI at the protrusion "P" decreases only nominally. Theretbre, according to these embodiments, expansion of the tubular T1 at the protrusion "P" thus strengthens the tubular Without breaching the tubular TI.
[0145] The magnitude of the protrusion ''P" can depend on several factors, including the length of the column of explosive pellets 640, the outer diameter of the explosive pellets 640, the amount of explosive material in the explosive pellets 640, the type of explosive material, the strength of the tubular T1, the thickness of the wall of the tubular Ti, the hydrostatic force bearing on the tubular Ti, and the clearance adjacent the tubular TI
being expanded, i.e., the width of the annulus "A" adjacent the tubular Ti that is to be expanded.
[0146] One way to manipulate the magnitude of the protrusion "P" is to control the amount of explosive force acting on the pipe or other tubular member TI, This cm be done by changing the number of pellets 640 aligned along the guide tube 616. For instance, the explosive force resulting from the ignition of a total. of ten pellets 640 is larger than the explosive three resui wig from the ignhion of a total of five similar pellets 640, As discussed above, the length "LI" (see FIG. 34C) of the expansion of the wall of the tubular T1 may be about two times the length of the column of explosive pellets 640. Another way to manipulate the magnitude of the protnision '"P" is to use pellets 640 with different outside diameters. The expansion tool discussed herein can be used with a variety of different numbers of pellets 640 in order to suitably expand the wall of pipes or other tubular members of different sizes.
Determining a suitable amount of explosive force (evg., the number of pellets 640 to be serially arranged on the guide tube 616), to expand the wall of a given tubular T. in a controlled manner, can depend on a variety of factors, including: the length of the column of explosive pellets 640, the outer diameter of the explosive pellets 640, the material of the tubular T1, the thickness of a wall of the tubular TI,, the inner diameter of the tubular T1, the outer diameter of the tubular T1, the hydrostatic force bearing on the tubular III, the type of the explosive (e_g., WAX, FINS) and the desired size of the protrusion "P" to be formed in the wall of the tubular TI, [0147] The above method of selectively expanding at least a portion of a wall of the tubular Ti via an expansion tool may be modified to include determining the following characteriOics of the tubular Ti :.a. material, of the tubular TI: a thickness. Of a wan of the tubular TI; an inner diameter of the tubular an outer diameter of the tubular Ti;
hydrostatic force bearing on the tubular TI; and a size of a protrusion "P".
to be formed in the .wail of the tubular Ti. Next, the explosive force necessary to expand, without puncturing, the wall of the tubular T1 to form the protrusion '`p", IS Calculated, or determined via teging, based on the above determined material characteristics.
[014S1 The determinations and calculation of the explosive force can be performed via a software program, and providing input, Which can then be executed on a computer. Physical hydrostatic testing of the explosive expansion charges yields data which may be input to develop computer models. The computer implements a central processing unit (CPU) to execute steps of the program. The program may be recorded on a computer-readable recording medium, such as a CD-ROM, or temporary storage device that is removably attached to the computer. Alternatively, the software program may be downloaded from a remote server and stored internally on a memory device inside the computer.
Based on the necessary force, a requisite number of eXplosiVe pellets 640 to be serially added to the guide tube 06 of the expansion toot is determined. The requisite number of explosive pellets 640 can be determined via the software program diseussed above, [01491 The requisite number of explosive pellets 640 is then serially added to the guide tube 610: After loading, the loaded expansion tool can be positioned within the tubular II, with the last pellet 640 in the column being located adjacent the detonation window 634. Next, the expansion tool can be actuated to ignite the pellets 640, resulting in a shock wave, as discussed above, that expands the wall of the tubular Ti radially outward, without perforating or cutting through the wall, to form the protrusion "P". The protrusion "P' can extend into the annulus "A" between an outer surtke of the tubular Ti and an inner surface of a wall of another tubular T2, [0150] In a test conducted by the inventors Ong the dual end firing explosive column tool 600 to radially expand a pipe timing a 6.4 centimeter (25 inch) wall thickness, an inner diameter of 2-2,9 centimeters (9.0 inches) and an outer diameter of 35,6 centimeters (14.0 inches), the expansion resulted in a radial protrusion measuring 45.7 centimeters (1$.0 inches) in diameter, That is, the., outer diameter of the pipe., increased from 35.6 centimeters (14.0 inches) to 45,7 centimeters (18,0 incheS) at the protrusion. The protrusion is a gradual expansion of the wa11 of the tubular TI The tnOre gradual expansion allows a greater expansion of the tubular T1 prior to exceeding the elastic strength of the tubular Ti, and failure of the tubular TI (te., the tubular being breeched).
[0151) The column of :eXplOsiVe pellets 640 can comprise a predetemyined or requisite) amount of explosive material sufficient to expand at least a portion of the wall of the pipe or other tubular into a protrusion extending outward into an annulus adjacent the wall of the pipe or other tubular. it is important to note that the expansion can be a controlled outward expansion of the wall of the pipe or other tubular, .which does not cause puncturing, breaching, penetrating or severing of the wall of the pipe or other tubular.
The annulus may be reduced between an outer surface of the wall of the pipe or other tubular .and an outer Wall of another tubular or a formation, [01.52] The protrusion "P" creates a ledge or barrier into the. annulus that helps seal that portion of the wellbore during Plug and abandonment operations in an oil well.
For instance, a sealant, such as cement or other sealing material, mud and/or debris, may exist in the annulus "A" on the ledge or barrier created by the protrusion The embodiments above involve using one column of explosive pellets 640 to selectiVely expand a portion of wall of a tubular into the annulus. One option is to use two or more columns of explosive pellets 640.
The explosive columns may be spaced at respective expansion lengths which, as noted previously, on vary as a function of the length Of the eXplOsive column unique to each application. After the =first protrusion is forined by the first explosive colutinn, the additional explosive column is detonated at a desired location, to expand the wall of the tubular TI at a second lk.)cation that is spaced from the first location and in a direction parallel to an axis of the expansion tool, to create a pocket outside the tubular TI between the first and second locations. The pocket is: thus created by sequential detonations of explosive columns. In another embodiment, the pocket may be formed by simultaneous detonations of explosives columns, For instance, two explosive Columns may be spaced from each other at first and Second locations, respectively, along the length of the tubular TL The lWo explosive columns are detonated simultaneously at the first and second locations to expand the.
wall of the tubular Ti at the first and second locations to create the pocket outside the tubular TI, between the first and second locations.

i01531 Whether one or multiple columns Of pxplosiNv pellets 640 are utilized, the method may further include setting a plug 19 below the deepest selective expansion zone, and then shooting perforating puncher charges through the wall of the inner tubular TI
above the top of the shallowest expansion zone, sO that there can be communication ports 21 from the inner diameter of the inner tubular Ti to the annulus "4" between the inner tubular Ti and the outer tubular TZ as shown in FIG. 34C. Cement 23, or other sealing material, may then be pumped to create a seal in the inner diameter of the inner tubular TI and in the annulus "A"
through the communication ports 21 between the inner tubular Ti and the outer tubular T2, as shown in FIG, 34C, The cement 2:3 is viscuS enough that, even if there is only a ledge/restriction (formed by the protrusion po, the cement 23 should be slowed do101 long enough to set up and seal, When the cement 23 is pumped into the annulus any and all material, (e.g,, cement, mud, debris), Will likely help effect the seal. One reason multiple columns of explosive pellets 640 may be used is the hope that if a seal is not achieved in the annulus "A" at the first ledge/restriction (formed by the protrusion P1), the seal may be provided by the additional ledge/restriction (formed by the additional protrusion). If the seal in the annuluS "-A" cannot be effected, the operator must cut the inner tubular T1 and retrieve it to the surface, and then go through the same plug and pump cement procedure for the Outer tubular T2, Those procedures can be expensive.
[0154] The methods discussedõherein have involved selectively expanding a wall of tubular while the tubular is inside of a wellbore. A variation of the embodiments discussed herein includes a method of selectively expanding a wail of tubular outside of the wellbore before the tubular is inserted into the wellbore. This variation may be carried out with the various expansion tools discussed herein. The various expansion tools discussed herein can be used to selectively expand the wall of tubular outside of the wellbore. The amount of explosive material used in this variation may be based upon the physical aspects of the tubular, the nature and conditions of the wellbore in Which the tubular will subsequently be inserted, and upon the type Of flinction the selectively expanded tubular is to perfOrin in the wellbore, The selective expansion of the tubular may (kCiti, for example, at a facility offsite from the location of the actual wellbore. The selectively expanded tubular may be inspected to confirm dimensional aspects of the expanded tubular, and then be transported to the wellsite for insertion into the wellbore.. IFOr instance, a method of selectively expanding, a wall of a tubular may involve positioning an expansion tool 'within the tubular, wherein the expansion tool contains an amount of explosive material for producing an explosive force sufficient to expand, without puncturing, the wall of the tubular. Next, the expansIon, loot may be actuated to expand the wall Of the tubular radially Outward, without petfottiting Or tutting through the wall of the tubular, to :font a protrusion that extends outward from the central bore of the tubular. The selectively expanded tubular may then be subsequently inserted into a v,ellbore.
[015.51 Although several preferred embodiments have been illustrated in the =OnIpanying drawings and describe in the foregoing specification, it will be understood by those of skill in the art that additional embodiments, modifications and alterations may be constructed from the principles disclosed herein. These various embodiments have been described herein with respect to selectively expanding a "pipe" or a 'tubular." Clearly, oiller embodiments of the tool of the present invention may be employed for selectively expanding any tubular good including, but not limited to, pipe, tubing, produCtiOnicaSing liner andiOr casing. Accordingly, use of the term "tubular" in the following claims is defined to include and encompass all forms of pipe, tube, tubing, casing, liner, and similar mechanical elements.

Claims

CLAMS
What is claimed is;
i. A shaped charge assembly for selectively expanding at least a portion of a wall of a tubular, comprising:
a housing comprising an outer surface facing away frorn the housing and an inner surface facing an interior of the housing; and a first explosive unit and a second explosive unit, wherein each of the first explosive unit and the second explosive unit comprises an explosive material, wherein each of The first explosive unit and the second explosive unit comprises a liner fiicing the inner surface of the housing, 'wherein a density of the liner is 6 Wee or less, wherein the liner is less ductal than copper, nickel, .zinc, zinc alloy, iron, tin, bismuth, and tungsten, and Wherein the liner is configured to MSC the first explosive unit and the second explosive unit upon ismition to expand, without puncturing., said at least a portion of the wall of the tubular to form a protrusion extending outward into an annulus adjacent the wall of the tubular.
2. The shaped charge assembly according to claim I , wherein the liner is formed of a glass material, 3. The shaped charge assembly according to claim I, wherein the liner is formed of a plastic material.
4. The shaped charge assembly according to claim 1, wherein the liner is perforated.
S. The shaped charge assembly according to clairn l, wherein each of the first explosive unit and the second explosive unit is geometrically symmetrical about an axis of revolution.

The shaped charge assetril* :according to claim wherein die density Of *e liner is asymmetric around at least one of the first explosive unit and the second explosive unit.
The shaped charge assembly according to claim , further comprising:
a tItSt Was* plate adjacent the first explosive unit, and a second backing plate achacent the second explosive unit;
an aperture extending along said axis of revolution from an outer surface of the first backing plate to at least an inner surface Of the second backing pilaw and an explosiVe detonator pOsitioned along said axis of revohttion and externally of the first backing plate.
A shaped charge assembly for seleetively expauding at least: a portion of a wall of a tubulai; comprising:
a housing comprising an outer surface facing away from the housing and an inner surface tailjOg a te0or of the hpOigg; and a first explosive unit and a Seetmd explosive unit, *lterein= each= of the firSt explosive unit and the second explosiVe unit coniprise an explosive material and a liner, wherein each of the first explosive unit and the second exploSive unit cmprise an exterior surface facing the inner surface of the housing, wherein the exterior surface and the liner have a generally hemispherical shape, and wherein the first explosive unit and the second explosive unit compriSe a predetermined amount of explosive suffiCient to expand, without puncturing, said at least a portion of the wall of the tubular to form a protrusion extending outward into an annulus adjacent the wall of the tubular.
9. The shaped charge assembly according to claim 8, wherein a jet fonned by igniting the first explOsive unit and the seeond explosive unit is less focused than ajet formed by igniting notm-hetitispherical explosiVe unitS, W. The shaped charge assembly according to claim S, *Wein each of the first =explosive unit and the second explosive unit is geometrically synunetrical about an axis of revolutiOt shaped charge assembly for selectively expanding at least a .poilion of a =wal (If a tubular, comprising:
a housing comprising an= outer surface facing away =from the housing and an inner surface facing an imerior of the housing;
a first explosiVe unit and a: second explosive unit, wherein each of the first ex0osive tmit and the second explosive unit comprises an explosive material=
aild a liner facing the inner surface of the housing; and an eXtraneous object located between the inner surface of the housing and the liner of the first explosive unit and the second explosive unit, wherein the extraneotis Object fouls a jet formed by igniting the first: cxplosiVe unit and the secOnd expiosiye unit, so that the jet Opands. Without puncturing, said at least a portion Of the wall of the tubular to form a protrusiottextending outward into an annulus adjacent the wall of the tubular.
The shaped charge assembly according to claim 11, wherein the extraneous object is one:of:a foam object, a rubber object, a Wood object, and a liquid object.
13: The shaped charg assembly accorchng to O&M I.1 'ereìn each of the first explosive unit and the second explosive unit is geometrically symmetrical about an axis of revolution, 14. A shaped charge assembly for selecti \=*y expanding at least n portion Of a wall of a tubular, comprising:
a housing comprising an outer surface facing away from the housing and an inner surface fa.cing an iriterior of the housinn;
a first eglosive unit and a second explosiye unit, wherein the first explosive unit comprises an =explosive utaterial: formed adjacent a first zinc or zinc alloy baelciit plate, wherein the second =eVlosive unit comprises an explosive material fOrmed adjacent te 'second zinc Or Zinc moy backing plate; and an aperture extending along said axis fretrn an outer surface of the first zinc or zinc alloy backing plate to at least an inner surface of the second zinc or zinc alloy backing plate, wherein the first explosive unit and the second explosive unit comprise a. predetermined amount of explosive sufficient to= expand, without puncturing, said at least a portioo 0 the wall of the tubular to foot a protrusion extending outward into an armohis adjacent the wall of the tubular.

15. The shaped charge assembly according to claim 14, wherein the housina is formed of a zinc or zinc alloy material.
14_ The shaped, charge assembly arcorcfing to elaiin 14, further 001nprising an =eXplOsive. detonator pcnned along said axis adjacent to, and externally of, the first zinc Or zinc alloy backing plate.
17. The shaped charge assembly according to claim 14, wherein each of the first backing plate and the seeond backing plate. 0OinpriseS an external surface opposite from Said ekplosive Material and perpemficular to :Said axis Of reVolution, and wherein the eizternal surface of a least one of the first. iinc or zigc alloy haelking plate and the second zinc or Zinc allOy backing plate has a plurality of blind pockets therein distributed in a pattern about said axis of rev o ut OIL
18, Ile shaped charge asserobly aCcording to elahn 14, wherein enh of the first expiOsiVe unit and the Second explisive twit is symmetrica1 About an Axis of rophition.
19. A method of reducing a leak in an annulus adjacent an outer surface of a tubular in a wellbore, the method comprising:
ittserOng a plug imo the tubular;
positiOnine an expansion tool within the tubular at a )00001 uphole of the plug, wherein the expansion tool contains an amount of explosive material based at least in part on a hydrostatic presspre bearing on the tubular, the amount of explosive material for producing an explosi ve fome wfficient to expand, uithont puncturing, the wall of the tubular;
and acwating the exposion tool to expand the wall of the tubular radially otit*ard, without perthrating or cutting through the wait of the tubular to fOrin a protrusion that extends into the annulus adjacent the outer surface of the wall of the tubular, wherein the protrusion seals the leak in the annular.
20: The method according to claim 1% further comprising;
actuating one or mOre puncher chargs in the tubular to punch Wes hi the wall of the tubular at a location uphole of the plug; and prOviding 4 sealant into the annulus through the holeS in the wall of the tubular, 21. A
niethod of selectively expanding walls of tWO Concentric tubulars comprising an inner tabular and an Outer tubular, the method comprising.:
positioning an expansion tool *ntni the inner tnbular, wherein the expansion tool contains an amount of explosive material based at least in part on a hydrostatic pressure bearing on at kast the inner tubular and the outer tubuhtr, the amount of explosive material for producing an explosive force sufficient to expand, without puncturing, a wail of the inner tubular and a wall of the outer tubular; and actuatitnt the OTsi011 tool once to eXpand both the Wall of the inner tubular and the wall of the outer tubular radially outward, without pelf Orating or cutting through the wall of the inner tubular and the wall of the Outer tubular, to form a protroSion of the wall of the inner tubular that extends into an annulus between the inner tubular and the outer tubular, and to form a concentric protrusion of the wall of the outer tubular into an annulus adjacent the outer surrape of the wall of the outer tubular, .A method of selectively ex pan ding, a wall of a tubular comprising a Central bore, the method comprising:
positioning an expansion tool within the tubular, wherein the expansion tool contaios an. anoint of explosive material for producing an: explosive foto sufficient to expand, without puncturing, the wall of the tubular;
&thiating the expansion tool to expand the wall of the tubular radially outward, without perforating or cutting throunh the wail of the tubular, 0 form a protrusion that extends outward front the central bore of the tubular; and inserting the selectively expanded tubular into a wellbore;