Abstract: A downhole tool for shutting off perforations has upper and lower sealing assemblies. A spacer separates the upper and lower sealing assemblies. The upper and lower sealing assemblies may engage a well above and below perforations to be shut off. A settable material may be injected into a space between the upper an lower assemblies, and into the perforations.

Abstract: A downhole tool for shutting off perforations has upper and lower sealing assemblies. A spacer separates the upper and lower sealing assemblies. The upper and lower sealing assemblies may engage a well above and below perforations to be shut off. A settable material may be injected into a space between the upper an lower assemblies, and into the perforations.

Abstract: A perforating apparatus for a gun string is presented. The apparatus experiences an axial load and potentially a radial load during use. A central charge-carrier supports shaped-charges and substantially bears the axial load on the apparatus during use. The charge-carrier is positioned within an exterior sleeve and the plurality of shaped-charges, upon detonation, perforate the exterior sleeve. The exterior sleeve does not bear a substantial portion of the axial load on the apparatus and can therefore be thinner and cheaper than in prior art assemblies. An annular space can be defined between the charge-carrier and exterior sleeve. The exterior tubular can bear the radial load due to differential pressure in one embodiment. Alternately, the apparatus includes radial support members extending between the charge-carrier and sleeve for transmitting radial load to the charge-carrier. Alternately, the sleeve and charge-carrier abut one another along a substantial portion of the length of the charge-carrier.

Abstract: A method for forming a perforation is disclosed. The method comprises positioning a perforating gun at a desired location in the formation. The perforating gun comprises a gun body and a charge carrier. The method further comprises disposing one or more shaped charges within the charge carrier. The one or more shaped charges comprise an outer case, an inner liner, and an explosive material retained between the outer case and the inner liner. The outer case of the shaped charge comprises one or more predefined fracture lines. The method further comprises detonating at least one shaped charge, wherein detonating the at least one shaped charge forms one or more perforations in the formation.

Abstract: In an embodiment, a sensing subassembly for use with a downhole tool comprises a housing, a cavity extending into the housing, a sensor disposed at least partially within the cavity, a shock mitigating member disposed between at least one end of the sensor and the housing, and at least one seal member disposed between the sensor and the housing. At least a portion of the sensor is in fluid communication with an exterior of the housing, and the shock mitigating member is configured to attenuate at least a portion of a shock wave between the housing and the sensor.

Abstract: A perforation gun string includes a perforation gun that forms at least part of the perforation gun string and a swellable material coupled to the perforation gun string. The swellable material is configured to be exposed to a downhole wellbore environment and to swell in response to exposure to the downhole wellbore environment. Further, the swellable material is configured to protrude beyond an outer surface of the perforation gun string when the swellable material swells.

Abstract: A secondary barrier for use in conjunction with an isolation device in a portion of a non-vertical wellbore comprises: a swellable material, wherein the swellable material: (A) has dimensions such that, prior to swelling, the secondary barrier is capable of being placed into the portion of the non-vertical wellbore, and (B) fills a void within the portion of the non-vertical wellbore, wherein the swellable material fills the void after the swelling of at least a portion of the swellable material has occurred, wherein the secondary barrier is positioned adjacent to the isolation device in the portion of the non-vertical wellbore. A method of creating a secondary barrier comprises: introducing the secondary barrier into the portion of the non-vertical wellbore; and contacting or allowing the swellable material to come in contact with the swelling fluid or the increase in temperature.

Abstract: A method can include interconnecting a well tool in a well tool assembly with a shock mitigating connection, the interconnecting being performed without threading, and positioning the well tool assembly in a wellbore. A well perforating assembly can include at least two perforating devices, a detonation train extending through the perforating devices, and a shock absorber positioned between the perforating devices. A method of assembling a perforating assembly can include, prior to installing the perforating assembly in a wellbore, pushing one perforating device connector into another perforating device connector without threading the connectors together, thereby: a) preventing disconnection of the connectors and b) making a connection in a detonation train. A well system can include a perforating assembly including multiple perforating guns and multiple shock absorbers. Each shock absorber may be interconnected between at least two of the perforating guns.

Abstract: A method for forming a perforation is disclosed. The method comprises positioning a perforating gun at a desired location in the formation. The perforating gun comprises a gun body and a charge carrier. The method further comprises disposing one or more shaped charges within the charge carrier. The one or more shaped charges comprise an outer case, an inner liner, and an explosive material retained between the outer case and the inner liner. The outer case of the shaped charge comprises one or more predefined fracture lines. The method further comprises detonating at least one shaped charge, wherein detonating the at least one shaped charge forms one or more perforations in the formation.

Abstract: A perforating apparatus for a gun string is presented. The apparatus experiences an axial load and potentially a radial load during use. A central charge-carrier supports shaped-charges and substantially bears the axial load on the apparatus during use. The charge-carrier is positioned within an exterior sleeve and the plurality of shaped-charges, upon detonation, perforate the exterior sleeve. The exterior sleeve does not bear a substantial portion of the axial load on the apparatus and can therefore be thinner and cheaper than in prior art assemblies. An annular space can be defined between the charge-carrier and exterior sleeve. The exterior tubular can bear the radial load due to differential pressure in one embodiment. Alternately, the apparatus includes radial support members extending between the charge-carrier and sleeve for transmitting radial load to the charge-carrier. Alternately, the sleeve and charge-carrier abut one another along a substantial portion of the length of the charge-carrier.

Abstract: A perforating gun can include at least one explosive component, and a shock mitigation device including a shock reflector which indirectly reflects a shock wave produced by detonation of the explosive component. Another perforating gun can include a gun housing, at least one explosive component, and a shock mitigation device in the gun housing. The shock mitigation device can include a shock attenuator which attenuates a shock wave produced by detonation of the explosive component. Yet another perforating gun can include a shock mitigation device with an explosive material which produces a shock wave that interacts with another shock wave produced by detonation of an explosive component in a gun housing.

Abstract: A perforation tool comprises an explosive charge comprising an explosive focal axis, a tool body containing the explosive charge, and a flowable material carried with the tool and disposed along the explosive focal axis. The flowable material is configured to be released by detonation of the explosive charge and flow to create at least a partial barrier to flow through the aperture in response to the perforation of the tool body by the explosive charge to form an aperture in the tool body.

Abstract: A method is presented for connecting and disconnecting sections of a work string for use in a subterranean wellbore. A preferred method of disconnecting includes the steps of positioning a stinger and a downhole tool assembly of a work string adjacent upper and lower sealing rams, such as in a BOP and lubricator assembly. The sealing rams are closed, defining a first and second pressure zone adjacent the tool. A differential pressure is applied across the pressure zones, moving a piston element in the tool assembly. Axial movement of the piston element causes relative rotational movement of cooperating locking elements. In one embodiment, the locking elements are rotated to an unlocked position and then move relative to one another axially in response to a biasing spring. The relative axial movement of the locking elements results in unlatching of a latching assembly, thereby disconnecting the tool and stinger.

Abstract: A perforation tool assembly is provided. The perforation tool assembly comprises an energy train, a first perforation gun, and a second perforation gun. The energy train comprises a moderator to reduce the speed of propagation of a detonation in a direction parallel to the axis of the perforation tool assembly. The first perforation gun comprises a plurality of explosive charges coupled to a first portion of the energy train. The second perforation gun comprises a plurality of explosive charges coupled to a second portion of the energy train, wherein the second portion of the energy train is coupled to the first portion of the energy train.

Abstract: A method can include interconnecting a well tool in a well tool assembly with a shock mitigating connection, the interconnecting being performed without threading, and positioning the well tool assembly in a wellbore. A well perforating assembly can include at least two perforating devices, a detonation train extending through the perforating devices, and a shock absorber positioned between the perforating devices. A method of assembling a perforating assembly can include, prior to installing the perforating assembly in a wellbore, pushing one perforating device connector into another perforating device connector without threading the connectors together, thereby: a) preventing disconnection of the connectors and b) making a connection in a detonation train. A well system can include a perforating assembly including multiple perforating guns and multiple shock absorbers. Each shock absorber may be interconnected between at least two of the perforating guns.

Abstract: A perforation gun string. The perforation gun string comprises a perforation gun that forms at least part of the perforation gun string; and a swellable material coupled to the perforation gun string. The swellable material is configured to be exposed to a downhole wellbore environment; the swellable material is configured to swell in response to exposure to the downhole wellbore environment; and the swellable material is configured to protrude beyond an outer surface of the perforation gun string when it swells.

Abstract: In an embodiment, a sensing subassembly for use with a downhole tool comprises a housing, a cavity extending into the housing, a sensor disposed at least partially within the cavity, a shock mitigating member disposed between at least one end of the sensor and the housing, and at least one seal member disposed between the sensor and the housing. At least a portion of the sensor is in fluid communication with an exterior of the housing, and the shock mitigating member is configured to attenuate at least a portion of a shock wave between the housing and the sensor.

Abstract: A method is presented for connecting and disconnecting sections of a work string for use in a subterranean wellbore. A preferred method of disconnecting includes the steps of positioning a stinger and a downhole tool assembly of a work string adjacent upper and lower sealing rams, such as in a BOP and lubricator assembly. The sealing rams are closed, defining a first and second pressure zone adjacent the tool. A differential pressure is applied across the pressure zones, moving a piston element in the tool assembly. Axial movement of the piston element causes relative rotational movement of cooperating locking elements. In one embodiment, the locking elements are rotated to an unlocked position and then move relative to one another axially in response to a biasing spring. The relative axial movement of the locking elements results in unlatching of a latching assembly, thereby disconnecting the tool and stinger.

Abstract: A perforation tool assembly comprises an energy train, a first perforation gun, and a second perforation gun. The energy train comprises a moderator to reduce the speed of propagation of a detonation in a direction parallel to the axis of the perforation tool assembly. The first perforation gun comprises a plurality of explosive charges coupled to a first portion of the energy train. The second perforation gun comprises a plurality of explosive charges coupled to a second portion of the energy train, wherein the second portion of the energy train is coupled to the first portion of the energy train.

Abstract: A perforation tool assembly comprises an energy train, a first perforation gun, and a second perforation gun. The energy train comprises a moderator to reduce the speed of propagation of a detonation in a direction parallel to the axis of the perforation tool assembly. The first perforation gun comprises a plurality of explosive charges coupled to a first portion of the energy train. The second perforation gun comprises a plurality of explosive charges coupled to a second portion of the energy train, wherein the second portion of the energy train is coupled to the first portion of the energy train.