Other

W.t. Bell International, Inc.

Shell USA, Inc.

Rairigh, James G.

James G Rairigh

William T Bell

Walter Stam

An energetics tool is inserted downhole in a wellbore tubular, which has a string of at least two axially separated shaped charges. With this tool N axially separated circumferential dents are created, using a string of only M=(N+1)/2 axially separated charges. N is an odd number of 3 or higher. Two additional axially separated dents may be created for each additional axially separated shaped charge that is added to the string. For example, by simultaneously detonating two shaped charges, it is possible to create three axially separated dents. By simultaneously detonating three shaped charges that are axially separated from each other, it is possible to create five axially separated dents. The shaped charges are contained in charge housings that are mechanically interconnected with a longitudinal connecting rod. The shaped charges are simultaneously detonated, whereby pressure waves from neighboring shaped charges interact to cause the additional dents.

Method of creating a plurality of longitudinally separated circumferential dents in a wellbore tubular

An explosive downhole tool includes a housing having an upper housing part on one side of a window section and a lower housing part on an opposite side of the window section. An explosive charge is provided within the housing for cutting or expanding the wall of the tubular. The majority of outer surface of at least one of the upper and lower housing part in cross-section is rounded so as to be devoid of corners. The rounded surface eliminates the presence of sharp corners that may catch on restrictions or protrusions in a wellbore so that the downhole tool is more easily conveyable within a wellbore. Another explosive downhole tool includes fins extending from the housing. The fins have a height that decreases in a direction away from the housing. The shape of the fins enables the downhole tool to be more easily conveyable within the wellbore.

Explosive downhole tools having improved wellbore conveyance and debris properties, methods of using the explosive downhole tools in a wellbore, and explosive units for explosive column tools

A method involves determining an expansion charge able to selectively expand, without perforating or cutting through, a wall of a tubular in a wellbore. The method includes determining conditions in the wellbore, including hydrostatic pressure bearing on the tubular in the wellbore, and a physical characteristic of the tubular. At a second location other than the wellbore, at least one of the conditions determined in the wellbore is reproduced, and a test tubular is provided at the second location. A test expansion charge able to expand, without perforating or cutting through, the wall of the test tubular, is determined based on the determined conditions. The determined test expansion charge is positioned within the test tubular, and is then actuated to expand the wall of the test tubular radially outward, without perforating or cutting through the wall, to form a test protrusion in the wall of the test tubular.

Methods of pre-testing expansion charge for selectively expanding a wall of a tubular, and methods of selectively expanding walls of nested tubulars

An explosive downhole tool includes a housing having an upper housing part on one side of a window section and a lower housing part on an opposite side of the window section. An explosive charge is provided within the housing for at least one of cutting and expanding the wall of the tubular. The outer surface of at least one of the upper and lower housing part is rounded so as to be devoid of corners. The rounded surface eliminates the presence of sharp corners that may catch on restrictions or protrusions in a wellbore so that the downhole tool is more easily conveyable within a wellbore. Another explosive downhole tool includes fins extending from the housing. The fins have a height that decreases in a direction away from the housing. The shape of the fins enables the downhole tool to be more easily conveyable within the wellbore.

A shaped charge assembly for selectively expanding a wall of a tubular includes a housing comprising an outer surface facing 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 wall of the tubular.

Shaped charge assembly, explosive units, and methods for selectively expanding wall of a tubular

A method of selectively expanding a wall of a tubular includes assembling an expansion tool comprising a plurality of bi-directional boosters, arranging a predetermined number of explosive pellets a serially-arranged column between the bi-directional boosters, positioning a duel end firing explosive column tool within the tubular, and detonating the bi-directional boosters to simultaneously ignite opposing ends of the serially-arranged column to form two shock waves. The shock waves collide to create an amplified shock wave that travels radially outward to impact the tubular and expand a portion of the tubular wall 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 protrusion extends into an annulus adjacent an outer surface of the wall of the tubular.

Dual end firing explosive column tools and methods for selectively expanding a wall of a tubular

A shaped charge assembly for selectively expanding a wall of a tubular includes first and second explosive units that are each symmetrical about an axis of revolution. Each explosive unit includes an explosive material that is liner-less. The first and second explosive units comprise a predetermined amount of explosive sufficient to expand, without puncturing, at least a portion of the wall of the tubular into a protrusion extending outward into an annulus adjacent the wall of the tubular.

A method of selectively expanding a wall of a tubular includes assembling an expansion tool comprising a plurality of bi-directional boosters, arranging a predetermined number of explosive pellets on the guide tube to be in a serially-arranged column between the bi-directional boosters, positioning a duel end firing explosive column tool within the tubular, and detonating the bi-directional boosters to simultaneously ignite opposing ends of the serially-arranged column to form two shock waves. The shock waves collide to create an amplified shock wave that travels radially outward to impact the tubular and expand a portion of the tubular wall 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 protrusion extends into an annulus between an outer surface of the wall of the tubular and an inner surface of a wall of another tubular.

A shaped charge assembly for selectively expanding a wall of a tubular includes a housing comprising an outer surface facing away from the housing and an opposing inner surface facing an interior of the housing. First and second explosive units are each symmetrical about an axis of revolution. Each explosive unit includes an explosive material formed adjacent to a backing plate and includes an exterior surface facing and being exposed to the inner surface of the housing. An aperture extends along the axis from one backing plate to the other backing plate. An explosive detonator is positioned along the axis adjacent to, and externally of, the one backing plate. The first and second explosive units comprise a predetermined amount of explosive sufficient to expand, without puncturing, at least a portion of the wall of the tubular into a protrusion extending outward into an annulus adjacent the wall of the tubular.

A 'mini-severing and back-off' tool includes a tubular magazine for a column of explosive pellets that are sized in diameter to provide a predetermined weight of explosive per unit column length. The tubular wall is vented at prescribed intervals for fluid pressure equalization between the internal bore of the tubular and the fluid pressure around the outside of the tubular. A fluid barrier is positioned between one end of the explosive pellet tubular and a detonator or an explosive booster provided to detonate the explosive pellet tubular. The explosive pellet tubular is positioned within the flow bore of a pipe string and adjacent to an intended pipe joint, and the explosive pellet tubular is detonated simultaneously with an application of torque on the pipe string, wherein the torque is applied in the thread release direction to disassemble the intended pipe joint.

Mini-severing and back-off tool with pressure balanced explosives

A 'back-off' tool comprises a magazine cylinder having one distal end of a long mast rod secured to the lower end-face of a magazine cylinder. The magazine cylinder is attached to an electrically detonated firing head. A first plurality of blind hole cavities penetrate the magazine cylinder end-face around the mast rod junction. A second plurality of elongated detonation cord ends are inserted into high temperature grease filled magazine cylinder cavities. From the cavities, the detonation cord lengths are bound to the rod surface along the rod length by non-metallic cord. The tool assembly is secured to the end of a wireline or tubing string for downhole placement and detonation.

String shot back-off tool with pressure-balanced explosives

An apparatus for, and method of, centering downhole well tools within the wellbore of a pipe comprises at least a pair of discs secured, respectively, to the distal end of a tool in a plane normal to a longitudinal tool axis, with an arc of each disc extended past the outer perimeter of the tool to at least an internal perimeter of an applied pipe bore and flexing to centralize the tool. In alternative embodiments, the discs are replaced by blades that are secured by a plurality of attachment points and fasteners, or by spring steel wires that are secured in radial apertures through an end boss by interference fit, soldering, swaging, or gluing.

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Houston, TX, United States of America

James G Rairigh