Abstract: The disclosed embodiments include a system and method in which a plurality of shock sensing subassemblies are arranged within the tool string to monitor the transient response of formation characteristics to various stimuli, including changes in pressure and temperature of a region of a wellbore that is nearby the formation. The systems and methods involve gathering measurements that reflect the transient response and comparing the measured data to predicted data. The results of the comparison can be used to determine formation properties and to refine and improve modeling processes used to generate the predicted data.

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: A perforating gun string may include a first perforating gun; a second perforating gun axially offset from the first perforating gun; a connector configured to interpose and couple the first and second perforating guns; and a detonation cord that passes axially through a central bore of the connector; and is connected to the first and second perforating guns. In some instances, the connector may have a body with an inner surface that defines the central bore, wherein the body has a ratio of an average diameter of the outer surface to an average diameter of the inner surface of about 1.2 to about 4.

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 sensing subassembly for use with a downhole tool comprises a housing, a cavity disposed within the housing, an electronic board disposed within the cavity, a stiffening member engaging the electronic board and configured to limit flexing of the electronic board, and a spring member configured to provide an isolation mount for the electronic board within the cavity.

Abstract: A plugging device, apparatus, and method. The plugging device includes an expandable member configured to move from a first, retracted position to a second, expanded position, a counter configured to count a number of restrictions in a conduit that the plugging device passes through, and an actuator configured to move the expandable member from the first position to the second position in response to the counter counting a predetermined number of restrictions. The expandable member in the expanded position prevents the plugging device from passing through a target restriction.

Abstract: A perforation tool assembly. The perforation tool assembly comprises a tool string connector, a perforation gun coupled to the tool string connector, and a structure configured to absorb mechanical energy released by firing one or more perforation guns. The coupling is configured to provide a limited range of motion of the tool string connector relative to the perforation gun. The tool string connector and the perforation gun retain the structure configured to absorb mechanical energy.

Abstract: The disclosed embodiments include a system and method in which a plurality of shock sensing subassemblies are arranged within the tool string to monitor the transient response of formation characteristics to various stimuli, including changes in pressure and temperature of a region of a wellbore that is nearby the formation. The systems and methods involve gathering measurements that reflect the transient response and comparing the measured data to predicted data. The results of the comparison can be used to determine formation properties and to refine and improve modeling processes used to generate the predicted data.

Abstract: A perforating gun string may include a first perforating gun; a second perforating gun axially offset from the first perforating gun; a connector configured to interpose and couple the first and second perforating guns; and a detonation cord that passes axially through a central bore of the connector; and is connected to the first and second perforating guns. In some instances, the connector may have a body with an inner surface that defines the central bore, wherein the body has a ratio of an average diameter of the outer surface to an average diameter of the inner surface of about 1.2 to about 4.

Abstract: A sensing subassembly for use with a downhole tool comprises a housing, a cavity disposed within the housing, at least one electronic component disposed within the cavity, and at least one isolating member disposed within the cavity. The at least one isolating member is configured to attenuate at least a portion of frequency components of a mechanical wave above a threshold and transmit at least a portion of frequency components below the threshold to the at least one electronic device.

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 plugging device, apparatus, and method. The plugging device includes an expandable member configured to move from a first, retracted position to a second, expanded position, a counter configured to count a number of restrictions in a conduit that the plugging device passes through, and an actuator configured to move the expandable member from the first position to the second position in response to the counter counting a predetermined number of restrictions. The expandable member in the expanded position prevents the plugging device from passing through a target restriction.

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 sensing subassembly for use with a downhole tool comprises a housing, a cavity disposed within the housing, an electronic board disposed within the cavity, a stiffening member engaging the electronic board and configured to limit flexing of the electronic board, and a spring member configured to provide an isolation mount for the electronic board within the cavity.

Abstract: A sensing subassembly for use with a downhole tool comprises a housing, a cavity disposed within the housing, an electronic board disposed within the cavity, a stiffening member engaging the electronic board and configured to limit flexing of the electronic board, and a spring member configured to provide an isolation mount for the electronic board within the cavity.

Abstract: A perforation tool assembly comprises a perforation gun, and a mass energy absorber coupled to the perforation gun. The mass energy absorber is configured to alter the propagation of mechanical energy released by firing one or more perforation guns. The mass energy absorber comprises a mass and at least one absorber, and the at least one absorber is disposed between the mass and the perforating gun.

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.