Abstract: A method and system for estimating a resistivity of a formation. A method for estimating a resistivity of a formation may comprise disposing a downhole tool into a borehole, wherein the downhole tool comprises a pad, an injector electrode, and a return electrode, injecting a current signal into the formation from the injector electrode, measuring a voltage signal between the injector electrode and the return electrode; and determining a formation resistivity and a formation dielectric constant from at least one of the voltage signal, at least one property of the downhole tool, and at least one property of the borehole. A system for estimating a resistivity of a formation may comprise a downhole tool. The downhole tool may comprise a pad, wherein the pad comprises an injector electrode and a return electrode. The system may further comprise a conveyance for disposing the downhole tool in a borehole and an information handling system.

Abstract: This disclosure presents systems to enable downhole bi-directional communications using a long length of electrical cable located within or partially within the internal diameter of a set of lower pipe segments and communicatively coupled to one or more upper pipe segments that utilize pipe cable attached to the outside diameter of each of the upper pipe segments. The long length of electrical cable and the one or more pipe cables from the upper pipe segments allow for communication coupling between downhole tools and surface equipment and surface computing systems. In some aspects, the pipe cable attached to the upper pipe segments can be protected from wear using clamps, collars, cages, and other protectors. In some aspects, an electrical signal generator and modulator can be located downhole proximate the downhole tools, uphole proximate one of the upper pipe segments, or proximate the surface equipment.

Abstract: This disclosure presents systems to enable downhole bi-directional communications using a long length of fiber optic cable located within or partially within the internal diameter of a set of lower pipe segments and communicatively coupled to one or more upper pipe segments that utilize pipe cable attached to the outside diameter of each of the upper pipe segments. The long length of fiber optic cable and the one or more pipe cables from the upper pipe segments allow for communication coupling between downhole tools and surface equipment and surface computing systems. In some aspects, the pipe cable attached to the upper pipe segments can be protected from wear using clamps, collars, cages, and other protectors. In some aspects, an optical signal generator and modulator, e.g., a light source, can be located downhole proximate the downhole tools, uphole proximate one of the upper pipe segments, or proximate the surface equipment.

Abstract: The subject technology relates to estimation of flow rates using acoustics in a subterranean borehole and/or formation. Other methods, systems, and computer-readable media are also disclosed. The subject technology includes drilling a wellbore penetrating a subterranean formation. The subject technology includes logging the wellbore using an acoustic sensing tool to obtain logged measurements, and obtaining acoustic pressure data associated with a leak source in the wellbore using the logged measurements. The subject technology also includes determining a flow rate (volumetric for fluid-based or mass for gas-based) of the leak source from the acoustic pressure data, and determining an area of the leak source from the determined flow rate. The subject technology also includes generating and providing, for display, a representation of the leak source using the flow rate and the area of the leak source.

Abstract: A method and system for estimating a resistivity of a formation. A method for estimating a resistivity of a formation may comprise disposing a downhole tool into a borehole, wherein the downhole tool comprises a pad, an injector electrode, and a return electrode, injecting a current signal into the formation from the injector electrode, measuring a voltage signal between the injector electrode and the return electrode; and determining a formation resistivity and a formation dielectric constant from at least one of the voltage signal, at least one property of the downhole tool, and at least one property of the borehole. A system for estimating a resistivity of a formation may comprise a downhole tool. The downhole tool may comprise a pad, wherein the pad comprises an injector electrode and a return electrode. The system may further comprise a conveyance for disposing the downhole tool in a borehole and an information handling system.

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 pump-down method includes deploying a tool in a well via a wireline and measuring a tension of the wireline. The method also includes determining a difference between the measured tension and a reference tension. The method also includes updating at least one of a pump rate and a wireline speed used for pump-down of the tool based on the difference and at least one control parameter obtained at least in part from prediction model results.

Abstract: A process for manufacturing a perforation gun casing includes providing a perforation gun housing that has a wall of nominal thickness and at least one scallop. Each scallop is a portion of the wall having a reduced thickness relative to the nominal wall thickness. The process also includes applying a selective annealing process to the perforation gun casing. The selective annealing process affects the material properties of the scallop but generally does not substantially affect the material properties of the portions of the wall having a nominal thickness.

Abstract: The subject technology relates to estimation of flow rates using acoustics in a subterranean borehole and/or formation. Other methods, systems, and computer-readable media are also disclosed. The subject technology includes drilling a wellbore penetrating a subterranean formation. The subject technology includes logging the wellbore using an acoustic sensing tool to obtain logged measurements, and obtaining acoustic pressure data associated with a leak source in the wellbore using the logged measurements. The subject technology also includes determining a flow rate (volumetric for fluid-based or mass for gas-based) of the leak source from the acoustic pressure data, and determining an area of the leak source from the determined flow rate. The subject technology also includes generating and providing, for display, a representation of the leak source using the flow rate and the area of the leak source.

Abstract: An acoustic tool for evaluating a geologic formation includes a housing member disposed between transmitter and receiver sections of the acoustic tool. The housing member defines a change in direction in an acoustic path extending therethrough such that acoustic signals traveling through the housing member are delayed and disrupted. The delay and disruption may isolate the acoustic signals traveling through the housing member from acoustic signals traveling through the geologic formation. Thus, the acoustic tool may facilitate identification and evaluation of acoustic signals traveling through the geologic formation.

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 pump-down method includes deploying a tool in a well via a wireline and measuring a tension of the wireline. The method also includes determining a difference between the measured tension and a reference tension. The method also includes updating at least one of a pump rate and a wireline speed used for pump-down of the tool based on the difference and at least one control parameter obtained at least in part from prediction model results.

Abstract: An apparatus comprising a housing, a chassis, and a plurality of heat-generating components. The chassis is biased into contact with a plurality of locations along an inner surface of the housing in response to elastic deformation of the chassis. The chassis includes a plurality of substantially planar surfaces each interposing ones of the plurality of locations. The plurality of heat-generating components are directly coupled to corresponding ones of the plurality of substantially planar surfaces.

Abstract: A process for manufacturing a perforation gun casing includes providing a perforation gun housing that has a wall of nominal thickness and at least one scallop. Each scallop is a portion of the wall having a reduced thickness relative to the nominal wall thickness. The process also includes applying a selective annealing process to the perforation gun casing. The selective annealing process affects the material properties of the scallop but generally does not substantially affect the material properties of the portions of the wall having a nominal thickness.

Abstract: An acoustic tool for evaluating a geologic formation includes a housing member disposed between transmitter and receiver sections of the acoustic tool. The housing member defines a change in direction in an acoustic path extending therethrough such that acoustic signals traveling through the housing member are delayed and disrupted. The delay and disruption may isolate the acoustic signals traveling through the housing member from acoustic signals traveling through the geologic formation. Thus, the acoustic tool may facilitate identification and evaluation of acoustic signals traveling through the geologic formation.

Abstract: An apparatus comprising a housing, a chassis, and a plurality of heat-generating components. The chassis is biased into contact with a plurality of locations along an inner surface of the housing in response to elastic deformation of the chassis. The chassis includes a plurality of substantially planar surfaces each interposing ones of the plurality of locations. The plurality of heat-generating components are directly coupled to corresponding ones of the plurality of substantially planar surfaces.