Abstract: A well logging tool apparatus is disclosed for conducting measurements in a borehole environment surrounding a borehole that traverses a subsurface formation. The apparatus includes an elongated conductive mandrel having a longitudinal axis, an antenna array positioned about the mandrel and including a transmitter for transmitting electromagnetic energy into the formation, and a sleeve positioned about the antenna array. The apparatus further includes a first set of electrodes and a second set of electrodes. Each electrode has an outer end that is exposed on the outer surface of the sleeve for conductive contact with an adjacent conductive borehole environment. Further, the first and second sets of electrodes are spaced longitudinally apart such that the transmitter is positioned longitudinally therebetween.

Abstract: A connection for tubulars includes an outer housing, an inner housing receivable in the outer housing, a retainer member coupled to and axially restrained with respect to the inner housing, and a slidable member mounted on the inner housing and movable between an engaged position and a disengaged position. The slidable member carries a plurality of engagement elements that form an interlocking joint between the retainer member and the outer housing when the slidable member is in the engaged position.

Abstract: A logging tool includes a tool body; a simple transmitter comprising a single antenna disposed on the tool body; four simple receivers, each comprising a single antenna, disposed on the tool body and spaced apart from the simple transmitter to form four arrays; and an electronic module for controlling operation of the four arrays, wherein the simple transmitter is configured to generate a magnetic field having a transverse component, wherein each of the four simple receivers is sensitive to the magnetic field generated by the simple transmitter, and at least one of the four simple receivers is sensitive to the transverse component of the magnetic field generated by the simple transmitter, and wherein the four arrays are configured to provide measurements at at least three depths of investigation.

Abstract: A well logging tool includes a housing; at least one piston moveably disposed on the housing; at least one sensor disposed on the at least one piston; a pressure compensation system coupled to the at least one piston such that a pressure at a back side of the at least one piston is substantially identical to a pressure outside the well logging tool; and a piston deployment mechanism for deploying the at least one piston. A method for well logging using a logging tool having at least one piston and a pressure compensating system, wherein the at least one piston includes at least one sensor, the method includes disposing the well logging tool in a borehole; deploying the at least one piston to establish a contact between the at least one piston and a wall of the borehole; and measuring a formation property using the at least one sensor.

Abstract: A well logging tool includes a conductive mandrel; an antenna array disposed around the conductive mandrel, wherein the antenna array comprises a plurality of antennas disposed on insulating supports and at least one contact spacer, the at least one contact spacer having at least one conductor channel having a contact assembly disposed therein; and a sleeve disposed over the antenna array, wherein the sleeve includes at least one electrode, the at least one electrode and the contact assembly adapted to provide a radially conductive path from an exterior of the well logging tool to the conductive mandrel.

Abstract: The invention refers to an axial antenna structure for use on a borehole wireline or while drilling logging tool. The antenna comprises an insulating medium and an electrical conductor disposed on the insulating medium. The electrical conductor is situated to have a magnetic dipole moment parallel to a longitudinal axis of the borehole logging apparatus. A tri-axial configuration combines the axial coil design and at least one transverse antenna structure substantially co-located with the axial antenna. The transverse antenna structure has a magnetic dipole moment orthogonal to the magnetic dipole moment of the axial antenna.

Abstract: The present invention provides a gun brake system adapted to slow the descent of a tool string in a well. In one embodiment, the brake system comprises a brake installed within the well and having a snug fitting restriction and one or more fluid channels extending along a portion thereof. The brake system further provides means for maintaining the fluid volume substantially constant within the production tubing to which the gun brake is installed.

Abstract: A connection for tubulars includes an outer housing, an inner housing receivable in the outer housing, a retainer member coupled to and axially restrained with respect to the inner housing, and a slidable member mounted on the inner housing and movable between an engaged position and a disengaged position. The slidable member carries a plurality of engagement elements that form an interlocking joint between the retainer member and the outer housing when the slidable member is in the engaged position.

Abstract: Techniques for implementing antenna configurations with substantially co-located axes are disclosed. A method for constructing co-located antennas includes winding a first antenna on a support, the first antenna having a first magnetic dipole in a first orientation; and winding a second antenna on the support through a first set of openings in the support, the second antenna having a second magnetic dipole in a second orientation, wherein the first orientation is different from the second orientation, and wherein a center of the first magnetic dipole substantially co-locates with a center of the second magnetic dipole.

Abstract: Shield apparatus are provided for use with logging instruments equipped with transverse magnetic dipole antennas. Flexible dielectric strips and dielectric cylindrical bodies are implemented with conductive elements in various patterns to form Faraday shield structures. The shields provide an extended conductive surface to the instrument support member and redirect axial currents along the borehole, protecting the underlying antennas from the undesired effects of these currents.

Abstract: An apparatus and method provides an anchoring apparatus for use in a wellbore that comprises a gripping assembly and an actuation assembly. In one arrangement, the actuation assembly includes a motor and a module having at least a compressible element (e.g., a hydraulic module) between the motor and the gripping assembly. Upon activation, the motor actuates the hydraulic module to cause activation of the gripping assembly. In one arrangement, the anchoring apparatus is designed to pass through a tubing or other restriction in the wellbore. When in the retracted state, the gripping assembly of the anchoring apparatus has an outer diameter that is smaller than an inner diameter of the tubing. When in the expanded state, the gripping assembly of the anchoring apparatus has an outer diameter than is substantially the same as the inner diameter of the liner to enable engagement of the gripping assembly against the liner.

Abstract: Shield apparatus are provided for use with logging instruments equipped with transverse magnetic dipole antennas. Flexible dielectric strips and dielectric cylindrical bodies are implemented with conductive elements in various patterns to form Faraday shield structures. The shields provide an extended conductive surface to the instrument support member and redirect axial currents along the borehole, protecting the underlying antennas from the undesired effects of these currents.

Abstract: The present invention provides a gun brake system adapted to slow the descent of a tool string in a well. In one embodiment, the brake system comprises a brake installed within the well and having a snug fitting restriction and one or more fluid channels extending along a portion thereof. The brake system further provides means for maintaining the fluid volume substantially constant within the production tubing to which the gun brake is installed.

Abstract: An apparatus and method provides an anchoring apparatus for use in a wellbore that comprises a gripping assembly and an actuation assembly. In one arrangement, the actuation assembly includes a motor and a module having at least a compressible element (e.g., a hydraulic module) between the motor and the gripping assembly. Upon activation, the motor actuates the hydraulic module to cause activation of the gripping assembly. In one arrangement, the anchoring apparatus is designed to pass through a tubing or other restriction in the wellbore. When in the retracted state, the gripping assembly of the anchoring apparatus has an outer diameter that is smaller than an inner diameter of the tubing. When in the expanded state, the gripping assembly of the anchoring apparatus has an outer diameter than is substantially the same as the inner diameter of the liner to enable engagement of the gripping assembly against the liner.

Abstract: A perforating gun includes a guide, a first charge unit, a second charge unit and a linkage. The first and second charge units are coupled to the guide. The second charge unit is capable of being in a collapsed position for passing the second charge unit through a tubing and is capable of being in an expanded position for detonating the second charge unit. The linkage is connected to the second charge unit to communicate an applied force to cause the second charge unit to move the second charge unit along the guide toward the first charge unit when the second charge unit is at least partially in the expanded position.

Abstract: Apparatus and method for cooling a component inside a tool includes a container and a plurality of heat sinks positioned in the container. The components are positioned in the container with the heat sinks for maintaining a reduced temperature inside the container. Further, an insulating layer and a reflective layer surround the heat sinks and components to reduce heat transfer. Alternatively, the container can have a hollow wall that encloses the space in which a heat sink material (such as an eutectic material) is disposed. The components to be protected are located in the container. The eutectic material includes a composition having tin and zinc. The insulating layer includes a container that stores a vacuum layer, such as a dewar flask.

Abstract: An apparatus and method provides an anchor device for use in a wellbore that comprises an actuator assembly responsive to an actuating signal, an operator coupled to the actuator assembly, and an engagement member moveable to a set position by the operator when actuated by the actuator assembly to set the anchor device. The anchor device may be employed in various tool strings, such as a perforating tool string. In one arrangement, the anchor device provides an automated retraction mechanism that is activated after a predetermined delay. In another arrangement, a retract signal may be supplied to activate the retraction mechanism.

Abstract: A perforating gun includes a guide, a first charge unit, a second charge unit and a linkage. The first and second charge units are coupled to the guide. The second charge unit is capable of being in a collapsed position for passing the second charge unit through a tubing and is capable of being in an expanded position for detonating the second charge unit. The linkage is connected to the second charge unit to communicate an applied force to cause the second charge unit to move the second charge unit along the guide toward the first charge unit when the second charge unit is at least partially in the expanded position.

Abstract: An apparatus and method for sealing an inner wall of a portion of a casing positioned in a well employs an inflatable sleeve having an outer surface and a conformable composite sleeve of curable composition extending around the outer surface of the inflatable sleeve. The inflatable sleeve is inflated to compress the composite sleeve against the surface of the inner casing wall. A local, activatable energy source, positioned downhole to deliver heat to the composite sleeve, is activated to cure the composite sleeve to form a hardened sleeve. The hardened sleeve presses against the inner wall of the casing portion to create a fluid seal. The embodiments shown have a number of preferred features. The local energy source includes an exothermic heat energy source for generating heat energy to cure the composite sleeve. The composite sleeve includes a mixture of resin and a curing agent, and the exothermic heat source includes thermite. The thermite includes a composition having a metal oxide and a reductant.