Abstract: A centralizing perforating gun for perforating a tubular in a wellbore include a gun housing, perforating charges positioned within the gun housing and detonatable to perforate the tubular, and a centralizing system. The centralizing system includes an extendable member configured to move between a retracted position and an extended position. The extendable member is configured to engage a surface of the tubular in the extended position, thereby biasing the centralizing perforating gun away from the surface of the tubular.

Abstract: Provided are compositions, methods, and systems that relate to downhole tractor wheels. A downhole tractor system comprising: tubular housing capable of being deployed downhole by wireline; plurality of wheels rotatably mounted to tubular housing, wheels having at least a portion of an outer surface comprising polymeric material. A method for conveying a downhole tool along an inner wall of a wellbore, the method comprising: disposing downhole tool coupled to downhole tractor within wellbore; providing energy to downhole tractor by way of wireline thereby rotating a wheel disposed on downhole tractor; frictionally engaging the inner wall of wellbore with wheel comprising polymeric material disposed on at least a portion of an outer surface of wheel thereby providing a compressive load between the inner wall of the wellbore and polymeric material; allowing downhole tractor to proceed along wellbore wall until downhole tractor reaches desired location; deploying downhole tool for use in wellbore.

Abstract: A centralizing perforating gun for perforating a tubular in a wellbore include a gun housing, perforating charges positioned within the gun housing and detonatable to perforate the tubular, and a centralizing system. The centralizing system includes an extendable member configured to move between a retracted position and an extended position. The extendable member is configured to engage a surface of the tubular in the extended position, thereby biasing the centralizing perforating gun away from the surface of the tubular.

Abstract: The disclosure provides a method of obtaining logging data of subterranean formations and a logging system for doing the same. One example method includes: (1) conveying a logging tool and downhole tractor through a gravity-conveyed section of a borehole, and (2) obtaining logging data from the logging tool during the conveying, wherein the downhole tractor is employed for at least a portion of the obtaining of the logging data. Another example method includes: (1) lowering a logging tool and an open-hole tractor through a gravity conveyed section of an open borehole, (2) raising the logging tool and the open-hole tractor through the gravity conveyed section, (3) obtaining, from the logging tool during the raising, logging data associated with the gravity conveyed section of the open borehole, and (4) employing the open-hole tractor for at least a portion of the raising of the logging tool during the obtaining.

Abstract: A perforating gun apparatus comprising a bulkhead connector located between an upper gun body thread and lower gun body thread. The bulkhead connector has seals in sealing arrangement with an upper gun body and a lower gun body with a support sleeve in contact with an inner groove support shoulder on the lower gun body. The support sleeve is radially deformable into the inner groove by a shockwave produced by firing the charges in the lower gun section. The deformation of the support sleeve attenuates the impact of the shockwave on the threaded connection. The bulkhead connector isolates the threaded connection from the pressure spike. The deformed support sleeve attenuates the shockwave from the charges firing in the upper gun section and transfers the resultant force away from the threaded connection.

Abstract: The disclosure provides a method of obtaining logging data of subterranean formations and a logging system for doing the same. One example method includes: (1) conveying a logging tool and downhole tractor through a gravity-conveyed section of a borehole, and (2) obtaining logging data from the logging tool during the conveying, wherein the downhole tractor is employed for at least a portion of the obtaining of the logging data. Another example method includes: (1) lowering a logging tool and an open-hole tractor through a gravity conveyed section of an open borehole, (2) raising the logging tool and the open-hole tractor through the gravity conveyed section, (3) obtaining, from the logging tool during the raising, logging data associated with the gravity conveyed section of the open borehole, and (4) employing the open-hole tractor for at least a portion of the raising of the logging tool during the obtaining.

Abstract: A system including a casing string having one or more casing segments, a logging tool, and one or more float valves. The casing string can have a distal end and a proximal end with the logging tool detachably coupled with the distal end thereof. The one or more float valves can be coupled with a distal end of the logging tool. The logging tool can have a battery power source transitionable between a standby power mode and a full power mode. The casing string is operable to be disposed in a wellbore and transition the logging tool from the standby power mode to the full power mode upon placement within a predetermined portion of the wellbore.

Abstract: A method and system for synchronizing downhole tractor and surface winch deployment includes deploying a tractor and deploying wireline from a winch, obtaining readings of wireline tension, and adjusting the speed of the tractor to match the winch speed. If the tractor and winch speeds appear substantially matched, periodically adding and/or removing slack in the wireline while observing the wireline tension can confirm if the tractor and winch are still synchronized.

Abstract: A system including a casing string having one or more casing segments, a logging tool, and one or more float valves. The casing string can have a distal end and a proximal end with the logging tool detachably coupled with the distal end thereof. The one or more float valves can be coupled with a distal end of the logging tool. The logging tool can have a battery power source transitionable between a standby power mode and a full power mode. The casing string is operable to be disposed in a wellbore and transition the logging tool from the standby power mode to the full power mode upon placement within a predetermined portion of the wellbore.

Abstract: An automated system for assessing pumpoff risk can be used to warn operators and/or control machinery in order to avoid pumpoff. Pumpoff risk is assessed through the use and/or comparison of one or more models of pumpoff risk. These models can include a sand build up model (e.g., to determine the threshold buildup size where pumpoff risk is too great), a line speed increase model (e.g., to determine the maximum flow rate allowable given a maximum support line feed rate), a residual error comparison model (e.g., to compare the deviation of predicted tension from actual tension), and a statistical analysis model (e.g., to determine likelihood of pumpoff given statistical probability of each of a multitude of possible scenarios).

Abstract: A perforating gun apparatus for use in a wellbore comprising at least one explosive component and a disintegration-resistant porous material. The disintegration-resistant porous material minimizes fluid shock propagation from a perforated reservoir resulting from the inrush of fluid and debris. A system and method of minimizing fluid shock propagation effects in a perforating gun apparatus using a disintegration-resistant porous material to attenuate fluid pressure waves during a perforation operation in a subterranean well.

Abstract: A downhole formation fluid sampler. The sampler includes at least one sampling chamber having an internal fluid chamber, a fluid inlet operable to receive a formation fluid and a fluid outlet. An inflatable bag is disposed within the internal fluid chamber. The inflatable bag is operably associated with the fluid inlet. A fluid cushion is disposed within the internal fluid chamber exterior of the inflatable bag such that filling the inflatable bag with the formation fluid through the fluid inlet displaces the fluid cushion from the internal fluid chamber through the fluid outlet.

Abstract: At least one crack designator for a perforating gun, wherein the gun includes a longitudinal direction, a lateral direction, and at least one scallop, wherein each crack designator is capable of redirecting crack growth from the lateral direction to the longitudinal direction of the gun. The designator may be located in one of the scallops, extend from an expected exit hole in the gun to an edge of one of the scallops, and be capable of redirecting crack growth from a lateral direction to a longitudinal direction of the gun. In preferred embodiments, the designator in each scallop is arranged in a spider pattern or concentric circles. The designator is preferably formed by machining, etching, or laser ablation. The designator may have a lower fracture toughness or lesser stiffness than surrounding material of the gun.

Abstract: A tool for influencing electrically conductive paths using ferrofluids in a downhole system. The downhole system can include a tool body, a source of ferrofluid, and a magnet. The magnet can provide a magnetic field that influences an electrically conductive path within an annulus between the tool body and a wellbore formation by arranging the ferrofluid from the source in the annulus.

Abstract: A through tubing bridge plug (200) for providing a gripping and sealing engagement with a casing string of a wellbore. The bridge plug (200) includes an actuation rod (208), an anchor assembly (212), a pair of compression assemblies, each including a support assembly (216, 242) and an anti extrusion assembly (220, 238) and a packing assembly (224) disposed about the actuation rod (208) between the compression assemblies. Responsive to longitudinal movement of the actuation rod (208), the anchor assembly (212) establishes the gripping engagement with the casing string, the compression assemblies are radially deployed such that the anti extrusion assemblies (220, 238) are supported by the support assemblies (216, 242) and the packing assembly (224) establishes the sealing engagement with the casing string.

Abstract: A perforating gun apparatus for use in a wellbore comprising at least one explosive component and a disintegration-resistant porous material. The disintegration-resistant porous material minimizes fluid shock propagation from a perforated reservoir resulting from the inrush of fluid and debris. A system and method of minimizing fluid shock propagation effects in a perforating gun apparatus using a disintegration-resistant porous material to attenuate fluid pressure waves during a perforation operation in a subterranean well.

Abstract: A tool for isolating objects in a wellbore using ferrofluids in a downhole system is provided. The downhole system can include a tool body, a source of ferrofluid, and a magnet. The magnet can magnetically couple with the ferrofluid from the source for arranging the ferrofluid adjacent to the tool body for isolating an object positioned in a wellbore from effects of fluids present in the wellbore.

Abstract: Certain aspects and features of the present disclosure relate to an automated system for assessing pumpoff risk, which can be used to warn operators and/or control machinery in order to avoid pumpoff. Pumpoff risk is assessed through the use and/or comparison of one or more models of pumpoff risk. These models can include a sand build up model (e.g., to determine the threshold buildup size where pumpoff risk is too great), a line speed increase model (e.g., to determine the maximum flow rate allowable given a maximum support line feed rate), a residual error comparison model (e.g., to compare the deviation of predicted tension from actual tension), and a statistical analysis model (e.g., to determine likelihood of pumpoff given statistical probability of each of a multitude of possible scenarios).

Abstract: A method for operating a well tractor is presented. The method involves running a well tractor coupled to a wireline into a wellbore and supplying an amount of electric power to the well tractor to operate the well tractor at a first speed to urge the wireline through the wellbore at a first force. A variable gear ratio transmission of the well tractor is adjusted and an amount of electric power is supplied to the well tractor to operate the well tractor at a second speed different than the first speed to urge the wireline through the wellbore at a second force different than the first force based on adjusting the variable gear ratio transmission.

Abstract: At least one crack designator for a perforating gun, wherein the gun includes a longitudinal direction, a lateral direction, and at least one scallop, wherein each crack designator is capable of redirecting crack growth from the lateral direction to the longitudinal direction of the gun. The designator may be located in one of the scallops, extend from an expected exit hole in the gun to an edge of one of the scallops, and be capable of redirecting crack growth from a lateral direction to a longitudinal direction of the gun. In preferred embodiments, the designator in each scallop is arranged in a spider pattern or concentric circles. The designator is preferably formed by machining, etching, or laser ablation. The designator may have a lower fracture toughness or lesser stiffness than surrounding material of the gun.