Abstract: A free point tool comprises an elongated main shaft assembly and a low mass sensor assembly coaxially and slidingly disposed over the elongated main shaft. The low mass sensor assembly is adapted to be supported within the down hole casing by first and second drag spring centralizers coupled respectively to upper and lower ends of the low mass sensor assembly. The low mass sensor assembly comprises a magnetic amplifier sensor disposed in a sensor body and having a variable inductance proportionally responsive to longitudinal and rotational displacement of an adjacent sensor plate portion of a movable sensor sleeve concentric with and enclosing the sensor body, wherein the sensor sleeve is attached to the first drag spring centralizer and the sensor body is attached to the second drag spring centralizer.

Abstract: A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected.

Abstract: A well completion method and apparatus comprises a pipe string having a bottom attached boring bit and scraper. Above the bit at designated well fluid production locations, perforation assemblies are integrated into the pipe string. Each perforation assembly comprises a by-pass circulation mandrel and a perforation gun. The circulation mandrel is secured at opposite distal ends in threaded Y-adapter boxes. The perforating gun is secured in collar bores respective to the opposite end Y-adapters.

Abstract: A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected.

Abstract: A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected.

Abstract: A support mechanism for protecting an object is described. The support system includes at least one support or friction ring for providing dynamic protection to the object. One embodiment includes a support ring having corrugated bumps. Another embodiment includes multiple support rings axially separated by spacers. In another embodiment a support mechanism is provided having at least one friction ring in combination with O-rings. A compound optical coupler is also described, which has a self-wetting clear optical coupling gel and an elastomeric load ring.

Abstract: A support mechanism for protecting an object is described. The support system includes at least one support or friction ring for providing dynamic protection to the object. One embodiment includes a support ring having corrugated bumps. Another embodiment includes multiple support rings axially separated by spacers. In another embodiment a support mechanism is provided having at least one friction ring in combination with O-rings. A compound optical coupler is also described, which has a self-wetting clear optical coupling gel and an elastomeric load ring. In another aspect, a compound optical coupler assembly comprises a self-wetting optical coupling gel and also an amount of a stiffening agent.

Abstract: A shaped charge detonation booster comprises a tubular wall body of substantially constant outside diameter for enclosing an axial primer path that terminates with an enlarged main cavity volume. Preferably, the main cavity is positioned within the juncture plane of opposing shaped cutter charges. The tubular wall surrounding the primer path is substantially thicker than the tubular wall surrounding the main body and the explosive material within the main body is compacted more densely than the explosive material in the primer path.

Abstract: A shaped charge tubing cutter includes a minimal contact suspension to isolate the cutter explosive from the housing and sub structure. A charge detonation booster main-cavity is located on the juncture of the charge truncation planes. Explosive in the booster main-cavity is detonated by a shielded primer path. Explosive density in the primer path is less than the main-cavity density. A dense, powdered metal SC liner and an abruptly stepped jet window in the tubing cutter housing improve performance. The axial span of the jet window is preferably aligned with the axial span between the liner bases. A testing apparatus and procedure inexpensively verifies downhole performance.

Abstract: A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected.

Abstract: A shaped charge tubing cutter includes a minimal contact suspension to isolate the cutter explosive from the housing and sub structure. A charge detonation booster main-cavity is located on the juncture of the charge truncation planes. Explosive in the booster main-cavity is detonated by a shielded primer path. Explosive density in the primer path is less than the main-cavity density. A dense, powdered metal SC liner and an abruptly stepped jet window in the tubing cutter housing improve performance. The axial span of the jet window is preferably aligned with the axial span between the liner bases. A testing apparatus and procedure inexpensively verifies downhole performance.

Abstract: A liner for an explosive shaped charge is formed from a mixture of powdered metals into three or more conical sections wherein the axial height of the first two sections is 30% to 70% of the total liner height. The first conical section may be formed to an included angle of about 20° to about 60°. The second conical section is formed to a greater included angle of about 30° to about 70°. The third conical section is formed to a density less than that of the first and second section and to an included angle that is preferably greater than the first section and equal to or less than the second section.

Abstract: A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected.

Abstract: An isolator bar of acoustic instruments used in downhole applications is made of a substantially cylindrical tube of metal of the type from which downhole instrument housing is usually made. A plurality of slots are placed in the tube at angles which are between 10 to 80° angle relative to the longitudinal axis of the tube. The isolator bar is equipped with traditional mechanical means with which it is incorporated in the acoustic instrument, placed between an acoustic transducer and an acoustic sensor or sensors utilized in the instrument. The angled slots cause sound waves traveling through the isolator bar to travel through multiple and extended path to the acoustic sensor, without significantly weakening the structural strength of the isolator bar.

Abstract: A high voltage shunt regulator circuit includes a high voltage device with a predetermined reverse-conduction threshold connected in series with a thermal compensation device comprising a plurality of gate threshold amplifiers connected in series with one another. The high voltage device includes a plurality of zener diodes connected in series. Each of the gate threshold amplifiers includes a resistive voltage divider and a voltage-controlled resistive device, preferably a MOSFET. The voltage divider is formed by first and second resistors connected in series between first and second terminals of the gate threshold amplifier, with a MOSFET having its drain connected to the first terminal, its source connected to the second terminal, and its gate connected to an intermediate tap of the voltage divider.

Abstract: A &ggr;-ray tool and acoustic logging instrument combination includes in an elongated housing a transmitter for sound and at least one and preferably two, sound sensors located at predetermined distances above the transmitter. The sound sensors are separated from the sound transmitter by a steel tube that has a layer of lead bonded onto its exterior surface and has electronic components of the instrument placed into its interior. The portion of the housing that surrounds the lead bonded steel tube consists of fiberglass, polytetrafluoroethylene (TEFLON®) or other material which does not conduct sound whereby the lead-bonded tube and the immediate housing around it act as a sound isolator bar. The transmitter and the sound sensors are surrounded by portions of the housing that comprises slotted steel to allow free flow of acoustic energy through these portions of the housing.