Abstract: Methods and systems for logging a wellbore having a casing using ultrasonic logging are described. Traditional ultrasonic logging involves using a piezoelectric transducer that is spaced from the inner surface of the casing by a least a distance referred to as the “far-field” distance. Logging in the “far-field,” as traditionally done, avoids destructive interference. The methods and systems described herein allow logging in the “near-field.” Logging in the near-field using the described methods and systems overcomes several difficulties associated with acoustic logging, particularly in attenuative, dispersive, and deviated environments.

Abstract: A centralizer assembly replaces an existing centralizer of a wireline tool so the tool can be used with smaller casing, such as casing smaller than 6-in. The assembly includes first and second centralizer units that replace the existing centralizer on a mandrel. Each unit has a sleeve that fits in a recess of the mandrel, and each unit has slider blocks disposed together in the recess on opposing sides of a divider on the sleeve. Arms hingedly connected to the blocks on each unit connect together at a joint having a roller for engaging in the casing. On each unit, a common pin is disposed through the slider blocks, and biasing elements on the common pin bias the blocks toward one another with different amounts of bias.

Abstract: A single layer antenna path profile is provided. An antenna assembly for the single layer antenna profile includes a bobbin having a cylindrical body defining an outer radial surface, an inner radial surface, and a central axis. The antenna assembly also includes one or more channels defined in the outer radial surface. In some aspects, each channel is defined by a continuously curved inner surface having a constant radius. In some aspects, the inner surface extends more than 180 but less than 360 and thereby defines an opening in the body. The antenna assembly also includes a coil including a wire wrapped about the bobbin and received within the one or more channels. In some aspects, an arcuate portion of the wire extends through the opening such that a portion of the wire protrudes out of the channel.

Abstract: A centralizer assembly replaces an existing centralizer of a wireline tool so the tool can be used with smaller casing, such as casing smaller than 6-in. The assembly includes first and second centralizer units that replace the existing centralizer on a mandrel. Each unit has a sleeve that fits in a recess of the mandrel, and each unit has slider blocks disposed together in the recess on opposing sides of a divider on the sleeve. Arms hingedly connected to the blocks on each unit connect together at a joint having a roller for engaging in the casing. On each unit, a common pin is disposed through the slider blocks, and biasing elements on the common pin bias the blocks toward one another with different amounts of bias.

Abstract: Wellbore logging tools can include a coil antenna assembly that prevents breakage of a coil wire during downhole use under elevated pressure. The antenna assembly can include an insulator base used to help insulate the wires so elevated downhole pressures do not result in a short to a tool mandrel. The insulator base provides a recessed path for the in/out portions of the wire so manufacturing fixtures of the antenna assembly will not damage them.

Abstract: A single layer antenna path profile is provided. An antenna assembly for the single layer antenna profile includes a bobbin having a cylindrical body defining an outer radial surface, an inner radial surface, and a central axis. The antenna assembly also includes one or more channels defined in the outer radial surface. In some aspects, each channel is defined by a continuously curved inner surface having a constant radius. In some aspects, the inner surface extends more than 180 but less than 360 and thereby defines an opening in the body. The antenna assembly also includes a coil including a wire wrapped about the bobbin and received within the one or more channels. In some aspects, an arcuate portion of the wire extends through the opening such that a portion of the wire protrudes out of the channel.

Abstract: Wellbore logging tools can include a coil antenna assembly that prevents breakage of a coil wire during downhole use under elevated pressure. The antenna assembly can include an insulator base used to help insulate the wires so elevated downhole pressures do not result in a short to a tool mandrel. The insulator base provides a recessed path for the in/out portions of the wire so manufacturing fixtures of the antenna assembly will not damage them.

Abstract: A jar includes the following: a mandrel; an outer housing slidably disposed about the mandrel; a low pressure chamber having a first port and formed between the mandrel and the outer housing; a high pressure chamber having a second port and formed between the mandrel and the outer housing; a fluid passage between the first and second port; and a valve disposed in the fluid passage.

Abstract: Implementations described herein are directed to a pressure pulse well tool, which may include an upper valve assembly configured to move between a start position and a stop position in a housing. The pressure pulse well tool may also include an activation valve subassembly disposed within the upper valve assembly. The activation valve subassembly may be configured to restrict a fluid flow through the upper valve assembly and increase a fluid pressure across the upper valve assembly. The pressure pulse well tool may further include a lower valve assembly disposed inside the housing and configured to receive the fluid flow from the upper valve assembly. The lower valve assembly may be configured to separate from the upper valve assembly after the upper valve assembly reaches the stop position, causing the fluid flow to pass through the lower valve assembly and to decrease the fluid pressure across the upper valve assembly.

Abstract: Embodiments disclosed herein relate to a jar including the following: a mandrel; an outer housing slidably disposed about the mandrel; a ball stop housing disposed below the outer housing; a lower sub disposed below the ball stop housing; and a ball stop assembly disposed in the ball stop housing. The ball stop assembly includes a ball stop pivotally disposed in the ball stop assembly.

Abstract: Embodiments disclosed herein relate to a jar including the following: a mandrel; an outer housing slidably disposed about the mandrel; a ball stop housing disposed below the outer housing; a lower sub disposed below the ball stop housing; and a ball stop assembly disposed in the ball stop housing. The ball stop assembly includes a ball stop pivotally disposed in the ball stop assembly.

Abstract: A roller reamer includes a roller assembly deployed in a corresponding axial recess in a tool body. The roller assembly is retained in the axial recess via compound wedging action provided by at least one retention assembly. The retention assembly includes first and second wedges, the first of which converts a substantially radially directed force to an axially directed force and the second of which converts the axially directed force to a cross-axially directed retention force that retains the roller assembly in the axial recess.

Abstract: A pressure pulse generating tool may include an upper valve assembly disposed within the bore of a housing, where the upper valve assembly is configured to allow a fluid to flow through the upper valve assembly when in an open state. The upper valve assembly may also be configured to restrict the fluid from flowing through the upper valve assembly when in a closed state. The pressure pulse generating tool may further include a lower valve assembly disposed within the bore of the housing, where the lower valve assembly is configured to receive the fluid flow from the upper valve assembly. The lower valve assembly may also be configured to separate from the upper valve assembly in response to an increase in fluid pressure in an annulus defined between the upper valve assembly and the housing.

Abstract: A valve assembly includes a main housing having a central bore therethrough, an upper valve subassembly disposed within the main housing, the upper valve subassembly including an upper seat configured to contact a corresponding lower seat of a lower valve subassembly, and a flow diverter ring disposed proximate the upper seat of the upper valve subassembly, wherein the flow diverter ring is configured to direct a fluid flow radially away from the upper seat of the upper valve subassembly.

Abstract: Implementations described herein are directed to a pressure pulse well tool, which may include an upper valve assembly configured to move between a start position and a stop position in a housing. The pressure pulse well tool may also include an activation valve subassembly disposed within the upper valve assembly. The activation valve subassembly may be configured to restrict a fluid flow through the upper valve assembly and increase a fluid pressure across the upper valve assembly. The pressure pulse well tool may further include a lower valve assembly disposed inside the housing and configured to receive the fluid flow from the upper valve assembly. The lower valve assembly may be configured to separate from the upper valve assembly after the upper valve assembly reaches the stop position, causing the fluid flow to pass through the lower valve assembly and to decrease the fluid pressure across the upper valve assembly.

Abstract: A valve assembly includes a main housing having a central bore therethrough, an upper valve subassembly disposed within the main housing, the upper valve subassembly including an upper seat configured to contact a corresponding lower seat of a lower valve subassembly, and a flow diverter ring disposed proximate the upper seat of the upper valve subassembly, wherein the flow diverter ring is configured to direct a fluid flow radially away from the upper seat of the upper valve subassembly.

Abstract: Embodiments disclosed herein relate to a jar including the following: a mandrel; an outer housing slidably disposed about the mandrel; a ball stop housing disposed below the outer housing; a lower sub disposed below the ball stop housing; and a ball stop assembly disposed in the ball stop housing. The ball stop assembly includes a ball stop pivotally disposed in the ball stop assembly.

Abstract: A valve assembly includes a main housing having a central bore therethrough, an upper valve subassembly disposed within the main housing, the upper valve subassembly including an upper seat configured to contact a corresponding lower seat of a lower valve subassembly, and a flow diverter ring disposed proximate the upper seat of the upper valve subassembly, wherein the flow diverter ring is configured to direct a fluid flow radially away from the upper seat of the upper valve subassembly.

Abstract: A valve assembly includes a main housing having a central bore therethrough, an upper valve subassembly disposed within the main housing, the upper valve subassembly including an upper seat configured to contact a corresponding lower seat of a lower valve subassembly, and a flow diverter ring disposed proximate the upper seat of the upper valve subassembly, wherein the flow diverter ring is configured to direct a fluid flow radially away from the upper seat of the upper valve subassembly.