Abstract: Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In at least one embodiment, an AMR sensor is provided that includes barber pole structures having upper and low metal layers that are formed of different materials. The metal material closer to the AMR element is formed of a material that can be etched using an etching process that does not attack the AMR material. In some other embodiments, AMR sensors having segmented AMR sensing elements are described.

Abstract: Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In at least one embodiment, an AMR sensor is provided that includes barber pole structures having upper and low metal layers that are formed of different materials. The metal material closer to the AMR element is formed of a material that can be etched using an etching process that does not attack the AMR material. In some other embodiments, AMR sensors having segmented AMR sensing elements are described.

Abstract: An antifuse device is constructed from a bipolar junction transistor (BJT). The BJT includes a collector, a base, and an emitter. In one embodiment the BJT is formed inherently within a field effect transistor (FET), including a first doped region, a second doped region, a gate, and a body region. The collector of the BJT is realized by the first doped region of the FET, the emitter of the BJT is realized by the second doped region of the FET, and the base of the BJT is realized by the body region. A high resistance path exists between the collector and the base. A first input voltage is connected to the collector and a second input voltage is connected to the base. A switch connects the emitter to a fixed potential when the switch is closed.

Abstract: A heave compensated stabbing and landing tool and method for use on a floating platform comprises a tool attached to a heave compensator on the floating platform. The tool, attached at one end to a taut line anchored to the seabed, includes means for gripping, raising and lowering a tubing string. The tool is attached to the heave compensator, which is raised to tighten the anchor line and substantially eliminate relative motion between the end of the tubing string and the seabed. The tool grips the tubing string and lowers it to the seabed in a controlled manner.

Abstract: A hydraulically operated actuator employs multiple metal-to-metal static seals to isolate the hydraulic fluid and to isolate the actuator from surrounding contaminating (ambient) fluids. A housing contains at least two linearly spaced apart chambers. A piston reciprocates from a retracted position to an extended position (power stroke) and from the extended position to the retracted position (return stroke) in one of the chambers (hydraulic chamber). The hydraulic chamber is separated by the piston into two sections, one of which contains high pressure hydraulic fluid and the other of which contains low pressure hydraulic fluid. A first static metal seal ring unit is designed to seal first at the completion of the power stroke of the piston to isolate the low pressure hydraulic fluid section from external contaminating fluids which may be at a higher pressure.

Abstract: A metal seal plug for use in sealing a tubing run is disclosed. The plug includes upper and lower tubular housings connected together for limited movement therebetween by an inner mandrel. The lower housing contains a locking unit which when actuated locks into a recess formed in the tubing to lock the plug in the tubing. The upper housing contains an actuator for actuating the locking unit when the upper housing is forced down with respect to the lower housing. The lower housing also contains a metal seal ring which engages metal sealing surfaces on the tubing and on the lower housing to seal off the space between the plug and the tubing. The distance between the locking unit and the metal seal ring and the distance between the recess and the sealing surface on the tubing run are selected to ensure that the metal seal ring is properly loaded when the plug is locked in the tubing.

Abstract: Apparatus is disclosed for tieing at least one tubing string suspended in a well pipe from a subsea non-rotatable christmas tree located on the sea floor to a downhole hanger affixed to the well pipe. The tubing string has a tie-back tool arranged on its lower end which contains first orienting means. The hanger contains second orienting means which is engageable with the first orienting means to position the tie-back tool in a desired angular position. Means arranged on the tubing string permit the tie-back tool to rotate to such angular position without placing torsional load on the tubing string. The method in which the tubing string is tied to the hanger is also disclosed.

Abstract: A structure or template forms a tubular support structure for subsea equipment used in drilling and producing offshore oil and/or gas wells. The template contains production manifolding, remote and safety shut-in control, pump-separator, and pipeline connector subsystems. Certain of the structural tubes are segregated to form compartmented ballast chambers capable of being selectively flooded and dewatered. Certain other structural tubes form piling sleeves. The truss or framework of structural tubes include vertical and horizontal tubes, the latter forming circumferential members as well as interstitial supports. The uppermost of the circumferential members or "ring" also functions as a fender to protect the equipment within the template. The template is made negatively buoyant upon launch by flooding the compartmented ballast chambers, keelhauled (swung to a position underneath the keel of the drilling vessel), and then lowered to the subsea floor.

Abstract: A subsea pipeline hub is connected to the hub of an adjacent spool piece connected to an in-place manifold of a subsea structure used in the production of oil and/or gas. The pipeline hub is positioned relative to the opposing spool hub and a remotely operated pipeline connecting tool is lowered from the water's surface to the subsea structure using guidelines and structural guidance for alignment of the pipeline hub with the spool piece hub. The spool piece hub is then drawn to the pipeline hub and the hubs are clamped together by operation of the connecting tool. The seal in the connection can be tested by means of the connecting tool. The spool piece may be retrieved and replaced by the connecting tool if maintenance is needed. Connecting tool operations are powered by hydraulic fluid and controlled from the surface. The pipeline hub may be lowered vertically and pivoted into its position adjacent the spool piece or may be pulled into that position.

Abstract: An hydraulically operated failsafe valve actuator for use on non-rising valve stems, particularly in a subsea environment. A rotatable shaft is connected to the non-rising valve stem. In one embodiment the valve is actuated to open by a fluid pressure operated motor acting against the bias of a spring. Means connects means linearly movable along the shaft and converts the linear movement of the linear movable means to rotary movement of the shaft. Spring means moves the linearly movable means in one direction to cause the shaft to rotate in one direction. Fluid pressure means, including a fluid pressure operated motor, rotates the shaft in an opposite direction to cause the linearly movable means to move in an opposite direction along the shaft. In another embodiment the valve is actuated to open by a fluid pressure operated piston acting against the bias of the spring. The piston is mounted on the rotatable shaft and moves linearly along the shaft to cause the shaft to rotate.

Abstract: A structure or template forms a tubular support structure for subsea equipment used in drilling and producing offshore oil and/or gas wells. The template contains production manifolding, remote and safety shut-in control, pump-separator, and pipeline connector subsystems. Certain of the structural tubes are segregated to form compartmented ballast chambers capable of being selectively flooded and dewatered. Certain other structural tubes form piling sleeves. The truss or framework of structural tubes include vertical and horizontal tubes, the latter forming circumferential members as well as interstitial supports. The uppermost of the circumferential members or "ring" also functions as a fender to protect the equipment within the template. The template is made negatively buoyant upon launch by flooding the compartmented ballast chambers, keelhauled (swung to a position underneath the keel of the drilling vessel), and then lowered to the subsea floor.

Abstract: A valve stem system is described for use in submerged oil and/or gas production systems designed to improve the reliability of subsea valves. A remotely rotatable pressure cap is threadedly engagable onto and removable from a valve bonnet which is mounted on a valve. The valve bonnet surrounds one section of the valve stem of the valve and forms a metal-to-metal seal with the cap when the cap is threadedly made up on the valve bonnet. Another section of the valve stem extends into the cap. A spline is arranged on that section of the valve stem. A spline clutch is arranged on the interior of the cap and is engagable with the spline of the valve stem to cause, when engaged, rotation of the valve stem upon rotation of the cap. A coil spring is arranged within the cap to push or urge the spline clutch into engagement with the valve stem spline when the cap is removed from the valve bonnet. Bearings arranged between the valve bonnet and the valve stem permit rotation of the valve stem relative to the valve bonnet.

Abstract: A subsea pipeline hub is connected to the hub of an adjacent spool piece connected to an in-place manifold of a subsea structure used in the production of oil and/or gas. The pipeline hub is positioned relative to the opposing spool hub and a remotely operated pipeline connecting tool is lowered from the water's surface to the subsea structure using guidelines and structural guidance for alignment of the pipeline hub with the spool piece hub. The spool piece hub is then drawn to the pipeline hub and the hubs are clamped together by operation of the connecting tool. The seal in the connection can be tested by means of the connecting tool. The spool piece may be retrieved and replaced by the connecting tool if maintenance is needed. Connecting tool operations are powered by hydraulic fluid and controlled from the surface. The pipeline hub may be lowered vertically and pivoted into its position adjacent the spool piece or may be pulled into that position.