Exxon Production Research Company

Thomas W Childers

Joseph A Burkhardt

Dale V Johnson

Harry R Hanson

David P Herd

Hollis A Baugh

James B Greer

Arthur C Daughtry

John W McCaskill

Gervase M Chaplin

Roger J Koerner

Louis M Regan

Roy E Anderson

Albert R Sinclair

Bobby M Harkrider

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.

Heave compensated stabbing and landing tool

A plug is disclosed for sealing off in a tubing having a sealing surface. A housing contains an annular metal seal means and two sets of segmented expanding lockdown rings that react with three solid rings to provide a downward motion. The expanding lockdown rings consist of a solid tapered ring that has been cut into a number of arcs. When a tapered mandrel is forced down inside the arcs, the arcs are expanded to the outside diameter of the mandrel. As the arcs expand, they are wedged between the solid rings that have matching tapers. The solid rings react between locking dogs and a shoulder in the housing to provide the downward movement. By using several expanding lockdown rings and solid rings, a relatively great deal of vertical motion can be obtained through the combined wedging action of each ring. Means on the housing and the tubing may be used to limit the locking load on the annular seal means.

Metal seal tubing plug

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. A second static metal seal ring unit is designed to seal at the completion of the return stroke of the piston also to isolate the low pressure section from external contaminating fluids. Power for the return stroke is primarily supplied by springs, with biasing pressure from the external environment providing a lesser contribution. A third static metal seal ring unit may be employed to obtain a simultaneous seal with the first metal seal ring unit to isolate the high pressure section from the low pressure section at the completion of the power stroke of the piston.

Hydraulically operated actuator

A spring cushioned static seal hydraulically operated actuator is disclosed which contains a hydraulically driven piston arranged to reciprocate in a chamber. A spring couples the piston to a rotatable shaft which limits the torque placed on the shaft by the piston in its drive stroke. A return spring functions to return the piston and drive spring to their initial positions upon release of the hydraulic drive applied to the piston. A static seal on the piston seals at the completion of the drive stroke of the piston. The actuator may be used to operate a subsea diverter to direct 'pump down' or through flow line (TFL tools) through wye-branched flow passageways formed in a diverter body member located on a submerged well head.

Hydraulic actuator

A method is disclosed for measuring at the water's surface the distance between a submerged wellhead and a downhole tubing hanger located in a subsea well which includes lowering an electrical conductor cable through the wellhead until the weighted lower end of the cable engages the tubing hanger. The cable contains two tools, one of which is capable of emitting an electrical signal for transmission to the surface when the cable is picked up and the lower end of the cable disengages from the hanger and the other of which is capable of emitting another electrical signal when it passes a preselected point in the wellhead. The cable is picked up to generate one signal and raised until the other tool passes the preselected point in the wellhead to generate the other signal. The distance the cable has been raised between emission of the two signals is then added to the known distance between the lower end of the cable and the other tool to determine the distance between the wellhead and the tubing hanger.

Depth measurements

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. Initially, shearable means releasably secures the mandrel to the upper tubular member to prevent movement between the upper and lower housings. The lower end of the plug may be a closed nose member or a diverter to be positioned in a curved tubing run of a Y-spool.

An improved well packer for use in sour gas wells is disclosed. The improved packer includes a cylindrical mandrel encircled with a resilient metal seal ring, means for anchoring the packer at a predetermined vertical depth, means for radially expanding the seal rings so as to cause sealing engagement with the casing and mandrel, and ratchet means for maintaining the seal rings in expanded form. The packer is adapted to be run into the cased wellbore on tubing and is particularly useful in sour gas wells.

Well packers using metal to metal seals

Apparatus and method are disclosed for externally testing flanged or hubbed connections used on fluid conducting conduits. A ring gasket fits between the faces of the connecting flanges or hubs to effect a fluid tight seal. A test ring also fits between the faces of the hub or flange connection in a manner so as to form a space between the test ring and the ring gasket. Seal means closes the space between the test ring and the faces of the flanges or hubs. The outside diameter of the test ring is confined within fastening means which secures the hubs or flanges together. Fluid under pressure, used to test the effectiveness of the ring gasket seal, is applied to the space between the ring gasket and the test ring seal means. The pressure in that space falls when the ring gasket is defective but remains constant if the ring gasket is sound. Following the test, fluid pressure is bled off the space between the ring gasket and the test ring seal means. The test fluid pressure is applied to and bled from such space through a pressure port or passageway formed in the test ring or in one of the flanges or hubs.

Apparatus and method for externally testing conduit connections

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.

Method and apparatus for making subsea pipe connections

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. Spring means moves the piston in one linear direction to rotate the shaft in one direction. Fluid pressure moves the piston in an opposite direction to rotate the shaft in an opposite direction.

Rotary motion failsafe gate valve actuator

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. The sections of the valve stem may be separate members and a detent clutch arrangement may be used to connect these sections in order to limit overtorquing of the valve stem and associated valve. The pressure cap is rotated by a manipulator effector which rotates an extension shaft connected to the pressure cap.

Valve stem static seal system

A balanced stem fail-safe valve controls flow of fluids through a submerged pipeline. A closed subsea hydraulic pressure system operates or powers the valve. In the fail-safe mode the operating or reservoir pressure equals ambient sea pressure. A valve housing is arranged on the pipeline and a valve chamber is formed in the valve housing. A valve element is movable in the valve chamber between open and closed positions to control the flow of fluids through the pipeline. A first fluid pressure operable means is connected to the valve element to move the valve element to open position upon application of pump pressure to the first fluid pressure operable means. Electrically operated valves are used to direct the flow of power fluid to and from the valve. A spring is arranged in the valve housing to urge the valve element to its closed position in the event of power failure. A second fluid pressure operable means detached from the valve element engages the valve element upon application of operating or reservoir pressure to the second fluid pressure operable means to balance any unwanted force which might occur when the ambient pressure is greater than the internal valve pressure and permit the spring to close the valve element. The valve operator may be removable by means of a remotely operated manipulator for repair or replacement of the valve system or portions thereof.

Growing community of inventors

Mandeville, LA, United States of America

Thomas W Childers