Abstract: An apparatus comprises a first cluster of perforator guns positioned circumferentially around a central longitudinal axis at a first axial position, wherein the first cluster is configured in a closed position while the apparatus is being lowered to a perforator position in a wellbore. After the apparatus is lowered to the perforator position, the first cluster is to move to an expanded position such that the perforator guns are moved closer to a target that is to be perforated.

Abstract: A downhole tool for forming a seal in a wellbore includes a housing configured for attachment to a string usable to transport the tool in the wellbore to a target depth; a holding chamber disposed within the housing, the holding chamber configured to receive a combination of a metal, a metal oxide, and a negative thermal expansion material in the holding chamber; an initiator operable to initiate a chemical reaction; a pressure applicator configured to apply pressure to seal material in the holding chamber; and an opening in a surface of the housing through which the seal material is expellable from the holding chamber.

Abstract: A signal transfer assembly includes a signal transfer propellant assembly and a signal transfer connector tube in hydraulic communication with a signal transfer firing head. The signal transfer propellant assembly has a piston and a gas generating energetic material. The signal transfer connector tube has a bore and a first opening allowing fluid communication between a borehole fluid surrounding the connector tube and the bore. The piston generates a pressure pulse when propelled through the bore by the generated gas. The signal transfer firing head assembly includes a housing having a second opening allowing fluid communication between the housing bore and the borehole fluid. A related method includes forming a well tool by operatively connecting a signal transfer assembly as described above to a primary downhole tool and a secondary downhole tool; conveying the well tool into a wellbore using a work string; and activating the secondary downhole tool by initiating the primary downhole tool.

Abstract: There is an igniter system for igniting an energetic material. The igniter system includes a housing having a bore; an igniter located inside the bore; a ground wire directly connected to the igniter; and a signal wire directly connected to the igniter. The ground wire and the signal wire form an electrical circuit with the igniter for igniting the energetic material.

Abstract: A single-trip method and system for perforating casing allows displacement of a heavier completion fluid from the perforation zone by a lighter formation-compatible treatment fluid without the need for an extended rat hole or repositioning the working string. The perforating system includes bridge subs located above and below a perforating gun. The bridge subs bypass treatment fluid around the gun through one or more conduits located along the exterior of the gun into a discharge flow port located immediately below the lower bridge sub. The system may be hydrodynamically designed to maintain efficient fluid displacement characteristics of the discharge flow port. The external conduits are positioned to not interfere with perforation operations and may include parallel conjoined tubes. The perforating system may be lowered to a perforation position in the wellbore, and treatment fluid pumped through the discharge flow port to displace completion fluid prior to perforation operations.

Abstract: A tool for penetrating a tubular as described. The tool comprises at least one length of linear shaped charge, a carrier adapted to support the/each length of linear shaped charge, and at least one detonation mechanism for detonating the/each length of linear shaped charge. Upon detonation of the/each length of linear shaped charge, a length of material is projected outwardly from the/each length of linear shaped charge towards an internal surface of the tubular, which is thereby penetrated. The at least one length of linear shaped charge is arranged such that, upon detonation, the trajectory of at least one portion of the projected material intersects the trajectory of at least one other portion of projected material at or adjacent the internal surface of the tubular.

Abstract: A shaped charge carrier tool is provided that has particular utility for perforating well casing as a preparation for cement placement. A plurality, four or more elongated shaped charge carrier ribs having a high bending modulus are secured for radially expanded displacement around a central framing tube or rod. Radius rods link the ends of the carrier ribs to top and bottom hinge carriers. The hinge carriers encircle the framing tube and are free for axial translation along the framing tube. Articulating hinges connect the radius rods to the carrier ribs and to the hinge carriers. Opposed compressed coil springs provide a resilient bias on the hinge carriers to translate the carrier ribs radially outward against the interior surface of a well casing as the tool passes from a riser tube into a larger inside diameter well casing.

Abstract: Packers may be inflated within the wellbore to engage and isolate a portion of the wellbore casing. Charges included within the packers may then be fired to perforate the casing. According to certain embodiments, the charges may be located within drains in the packers that can be subsequently employed to induce and measure pressure changes within the casing and surrounding formation. The pressure measurements in turn can be used to determine the integrity and/or permeability of the casing.

Abstract: An apparatus for restraining the movement of a gun charge holder within a gun tube including a snap ring with an alignment end that engages an end fitting and the gun tube simultaneously, the snap ring further comprising a grounding hole to facilitate the grounding of the electronics and detonation devices within the gun charge holder.

Abstract: A perforation gun which provides a means to create perforations required for the hydraulic fracturing of rock formations for the production of natural gas, oil, and other oil well fluids and further comprises a gun body assembly having an inserted carrier tube to nest shaped charge canisters with built in primers, conical liner, and explosive material. The charges are positioned in various angular patterns along various phase angles to create specifically directed perforation tunnels which puncture scalloped areas of the aforementioned gun body and subsequently penetrate through the wellbore, well casing, well cement, and into the rock formations for the release and removal of natural gas, oil, and other oil well fluids after hydraulic fracturing.

Abstract: A downhole tool assembly for use in a wellbore includes a tubular body carrying an explosive which is selectively detonated to create a dynamic underbalance or overbalance effect in the wellbore. The tubular body has opposite ends provided with plug assemblies including plug elements movable between a normally collapsed state and an actuable expanded state. The plug elements are adapted to be actuated to the expanded state between the tubular body and an outer extent of the wellbore before the creation of the dynamic underbalance or overbalance effect to isolate a discrete segment of the wellbore to which the dynamic underbalance or overbalance effect is confined.

Abstract: An apparatus for deploying and activating a downhole tool activated by an explosive charge such as a drill pipe cutter or hole puncher. The apparatus includes a sealing member with an external wedge-shaped profile that forms a metal-to-metal partial seal with a profile at the top end of a pipe joint in a drill pipe string. The apparatus includes an impact force absorbing device that maintains a firing rod in a non-actuated position during impact of the apparatus. The apparatus includes a differential pressure piston that actuates at a pre-determined well bore pressure to release the firing rod to activate the downhole tool.

Abstract: A bending shock de-coupler for use with a perforating string can include perforating string connectors at opposite ends of the de-coupler. A bending compliance of the de-coupler may substantially increase between the connectors. A well system can include a perforating string including at least one perforating gun and multiple bending shock de-couplers, each of the de-couplers having a bending compliance, and at least two of the bending compliances being different from each other. A perforating string can include a bending shock de-coupler interconnected longitudinally between two components of the perforating string. A bending compliance of the bending shock de-coupler may substantially decrease in response to angular displacement of one of the components a predetermined amount relative to the other component.

Abstract: A system for use in borehole completion is provided and includes a perforating sub, a firing sub having a first port and an interior and including a firing assembly disposable within the interior and operably coupled to the perforating sub and a drilling fluid barrier, which is formed with a second port and is displaceable toward a position at which the first and second ports align to form a fluid path through the interior that is sufficiently pressurizable to actuate the firing assembly, a drop plug selectively engageable with the drilling fluid barrier to enable displacement thereof to the position in response to applied pressures and an isolation sub, into which the drop plug is receivable following disengagement thereof from the drilling fluid barrier.

Abstract: A method of small-charge blasting, a rock drilling unit and a front guide to be used therein. By means of a rock drill machine provided in the rock drilling unit, a hole is first drilled into a material to be excavated and, subsequently, a drilling tool is pulled out of the hole. Next, one or more propellants comprising a propellant charge are fed to the bottom of the hole through a propellant feed channel provided in connection with a feed beam. Then, the hole is sealed and the propellant is ignited, whereupon a high gas pressure is generated, which causes fractioning in the material to be excavated. During the feeding and ignition of the propellant, the rock drill machine is kept in a parallel direction with respect to the hole.

Abstract: A buffering device for use in conjunction with a downhole tool string, wherein the tool string includes a ballistics device. The buffering device includes a mandrel attached within a tool string and proximate to the ballistics device. An anchor is disposed on the mandrel and a disk plate is coaxially placed on the mandrel that is slideable thereon. The disk plate is proximate to the ballistic device. A resilient member, such as a spring, is coaxially placed on the mandrel between the disk plate and the anchor. The pressure wave produced by activation of the ballistic device pushes the disk plate toward the anchor and compresses the spring there between. Since the disk plate extends outward into sealing contact with casing lining the wellbore, compression of the spring dissipates energy waves produced by activation of the ballistic device.

Abstract: A technique is provided to form perforations in a wellbore. The formation of perforations is carefully controlled by a perforating device to create a series of sequential perforations in a desired arrangement. The perforating device is lowered to a desired location in the wellbore and then moved incrementally to enable sequential perforations in the desired arrangement.

Abstract: This invention refers to a recoverable, reinforced and vibration-damping plug for cased wells, said wells being for oil, water, gas or any other similar fluid; said plug may be used for conventional casing perforation, high penetration casing perforation and casing perforation using the tubing conveyed perforation system, comprising a pressure equalizing valve having an automatic drilling jar mounted over a holding body with sealing rings interleaved on the perimeter. The plug also comprises a safety latch for said valve, packing means and two sets of opposite, single clamps having a wall that anchor said plug to the casing, which provides an almost complete interlocking. Besides, it is furnished with vibration-damping means that may be rubber rings arranged in such a pattern that they may absorb the energy of the shots produced by the casing perforation, and so to avoid ruptures in the plug members.

Abstract: A method and apparatus for placement of continuous pre-split, gel explosive in an elongated borehole or cavity. An anchor is attached to one end of a selected length of continuous gel explosive. A suitable anchor is a flexible, plastic “pilgrim's hat” with a hole in the narrow, closed end. The size of the anchor depends on the width of the borehole; the flared skirt should be narrow enough to permit insertion of the anchor into the hole but wide enough to resist removal. One end of the explosive charge is pressed through the hole in the anchor. The remainder of the length of explosive is placed inside a tubular member, such as PVC pipe. The loaded pipe then is inserted into the borehole or cavity with the anchor leading. The pipe is used to push the anchor back into the hole to the desired depth. Then, the pipe is withdrawn. The flexible skirt on the anchor engages the sidewall of the borehole and thus resists removal with the pipe.

Abstract: Primer casing (1) comprising sleeve portion (5) and leading portion (5a), wherein sleeve portion (5) includes tabs (6) to retain primer (11) and blasthole engagement means (2), and wherein leading portion (5a) comprises nose cone (8). Engagement means (2) comprises an array of rigid, multiple projections that are hinged and movable between a retracted position and a blasthole engagement position. Explosive loading hose (13) locales within hose receiving sleeve (7) and can be used to push primer casing (1) into the desired location within the blasthole prior to filling the blasthole with bulk explosive. Methods of loading a blasthole comprising inserting primer (11) into primer casing (1) and positioning primer casing (1) at a desired location in a blasthole are also described and claimed.

Abstract: A method and apparatus for removing a tubular member (e.g., leg of an abandoned or obsolete fixed platforms in a marine environment) is provided. The apparatus includes a delivery system having a frame carrying explosive shaped charges. The frame includes charges having curved sections which can be moved relative to one another for engaging the inside bore of a tubular member to be severed. The charges are biased (e.g., spring loaded) to be moved automatically to an extended position that engages the tubular member (e.g., platform leg) when a trigger is activated from a remote location. The trigger can be a pin carried in a tube with wires connecting each curved charge section to the pin. When the pin is lifted from its tube, the wires are released enabling the springs to thrust the charges against the inside of a pipe, leg or tubular member to be cut. Once in this position, the charges can be fired.

Abstract: A method and apparatus for placement of continuous pre-split, gel explosive in an elongated borehole or cavity. An anchor is attached to one end of a selected length of continuous gel explosive. A suitable anchor is a flexible, plastic “pilgrim's hat” with a hole in the narrow, closed end. The size of the anchor depends on the width of the borehole; the flared skirt should be narrow enough to permit insertion of the anchor into the hole but wide enough to resist removal. One end of the explosive charge is pressed through the hole in the anchor. The remainder of the length of explosive is placed inside a tubular member, such as PVC pipe. The loaded pipe then is inserted into the borehole or cavity with the anchor leading. The pipe is used to push the anchor back into the hole to the desired depth. Then, the pipe is withdrawn. The flexible skirt on the anchor engages the sidewall of the borehole and thus resists removal with the pipe.

Abstract: A perforating gun assembly for use in perforating multiple intervals of at least one subterranean formation intersected by a cased wellbore and in treating the multiple intervals using a diversion agent, such as ball sealers. In one embodiment, the apparatus of the present invention comprises a perforating assembly having a plurality of select-fire perforating devices interconnected by connector subs, with each of the perforating devices having multiple perforating charges. The apparatus also includes at least one decentralizer, attached to at least one of the perforating devices, which is adapted to eccentrically position the perforating assembly within the cased wellbore so as to create sufficient ball sealer clearance between the perforating assembly and the inner wall of the cased wellbore to permit passage of at least one ball sealer.

Abstract: The present invention provides a method and apparatus for plugging a wellbore in a trip saving manner. In one aspect, the invention includes a cement retainer disposed on a run-in string and a radially expanded perforating assembly disposed below the cement retainer. In a single run, the apparatus provides for perforating a wellbore and squeezing cement through the perforations and into the formation therearound. In another aspect, a method of plugging the wellbore includes running a cement retainer and a radially expanded perforating assembly into a wellbore on a run-in string. After the cement retainer is set, a firing head is actuated to cause the perforating gun to discharge. After perforations are formed, cement is introduced from the cement retainer into the isolated area and squeezed through the perforations. Thereafter, the run-in string disengages from the cement retainer leaving behind the plug formed.

Abstract: A method and apparatus for placement of continuous pre-split, gel explosive in an elongated borehole or cavity. An anchor is attached to one end of a selected length of continuous gel explosive. A suitable anchor is a flexible, plastic “pilgrim's hat” with a hole in the narrow, closed end. The size of the anchor depends on the width of the borehole; the flared skirt should be narrow enough to permit insertion of the anchor into the hole but wide enough to resist removal. One end of the explosive charge is pressed through the hole in the anchor. The remainder of the length of explosive is placed inside a tubular member, such as PVC pipe. The loaded pipe then is inserted into the borehole or cavity with the anchor leading. The pipe is used to push the anchor back into the hole to the desired depth. Then, the pipe is withdrawn. The flexible skirt on the anchor engages the sidewall of the borehole and thus resists removal with the pipe.

Abstract: Reinforced borehole plugs useful in the presplitting and blast removal of earth formations, the improvements provided by the invention comprising inflatable devices intended to support stemming, explosives and the like at suspended locations within a borehole to produce desired blast results. The borehole plugs of the invention comprise inflatable sport balls such as are used on playgrounds as toys and which are reinforced according to the invention to maintain inflation within a borehole, a characteristic which playground balls can only inconsistently provide. The borehole plugs of the invention are preferably inflatable through use of valve structures which permit pumping of an inflating fluid into the plugs once the plugs are respectively suspended at desired locations within boreholes prior to filling the boreholes in whole or in part with stemming and/or explosives and the like.

Abstract: A process and apparatus for completing a subterranean well bore in at least one subterranean formation. At least one perforating gun assembly is positioned on the outside of casing in a subterranean well bore. A suitable signal, such as a hydraulic, electric or wave signal, is transported to the perforating gun assembly so as to detonate one or more explosive charges in the perforating gun assembly which are aimed toward the casing. At least one wall in the casing is perforated thereby establishing fluid communication through the wall of the casing. Usually, cement surrounding the casing and a subterranean formation surrounding the casing are also perforated to establish fluid communication between the formation and the interior of the casing.

Abstract: A tubing conveyed perforating apparatus is shown which includes a tubular firing section which carries a plurality of explosive charges. The explosive charges are initially aligned with regions of reduced wall area provided in a tubular firing section which initially surrounds the charges. A piston sleeve is mounted on the exterior of the firing section. The piston sleeve has a plurality of apertures which are initially aligned with the regions of reduced wall area in the tubular firing section and thus with the explosive charges. Detonation of the charges causes the piston sleeve to shift so that the piston sleeve apertures are out of alignment with openings formed in the tubular firing section by the detonation of the charges, thereby trapping any resulting debris within the interior of the tubular firing section. Firing of the explosive charges opens upper and lower circulating ports so that sand or other debris can be reverse circulated up the interior of the well string to the well surface.

Abstract: A perforation gun which provides a means to create perforations required for the hydraulic fracturing of rock formations for the production of natural gas, oil, and other oil well fluids and further comprises a gun body assembly having an inserted carrier tube to nest shaped charge canisters with built in primers, conical liner, and explosive material. The charges are positioned in various angular patterns along various phase angles to create specifically directed perforation tunnels which puncture scalloped areas of the aforementioned gun body and subsequently penetrate through the wellbore, well casing, well cement, and into the rock formations for the release and removal of natural gas, oil, and other oil well fluids after hydraulic fracturing.