Abstract: Hydrocarbon fluid recovery from wells extending into subterranean formations is stimulated by treatment of the near-wellbore formations with cryogenic liquid.

Abstract: Gas in association with liquids is produced from a wellbore by disposing a first tubing string having a first fluid communication path into the wellbore to near or below the bottom of a producing zone, disposing within the annulus between the first tubing string and the outer surface of the wellbore a second fluid communication path from near or below the bottom of the producing zone to an offtake line at the surface, disposing a choke means in at least one of the fluid communication paths, and producing gas while controlling the choke means to establish sufficient gas flow up the first fluid communication path so as to unload liquids from near or below the bottom of the producing zone and produce the liquids up the first tubing string in association with gas flow. In accordance with a preferred embodiment, the first tubing string has a sufficiently small diameter that liquids can be unloaded from the well over life of the production.

Abstract: A fluid actuated detonating device is shown being used to activate explosive devices in a borehole. The detonating device has an explosive detonation charge arranged in a housing wherein a rupture disc in the wall of the housing separates the explosive charge from a fluid environment so that when pressure in the fluid environment is raised to a sufficient level the rupture disc fails and communicates a sudden pressure wave to the explosive to detonate the explosive.

Abstract: This invention relates to an improved termination connection for advanced fiber composite cables of the type comprised of fibers fixed in a matrix binder. In particular, the composite cable is provided with one or more ribs of tension wound binder impregnated fiber cured on the end portion thereof. Potting material is secured over the ribs at the end of the cable preferably having a parabolically curved outwardly tapered contour to distribute the longitudinal and transverse forces over the fibers in the cable.

Abstract: The present invention provides a single trip system for placing perforating apparatus and sand control equipment in a wellbore. This system includes a casing string equipped with extendible pistons and a pumpable activator plug for extending the pistons. Additionally, this system utilizes a single gravel-pack and completion tool string. Further, this system includes a means for opening the extendible pistons to fluid flow.

Abstract: A VASPS (vertical annular separation and pumping system) is integral with a floating production vessel such as a TLP. The head section of the VASPS is located at the deck level of the vessel. The tail section is located at or near the bottom of the body of water. The head and tail sections are in fluid communication by a riser having at least two fluid passageways (conductors). The invention constitutes an improvement on the VASPS unit described and claimed in U.S. Pat. No. 4,900,433.

Abstract: This invention is directed to a system for determining the position and depth of downhole equipment in a wellbore which includes an elongate spoolable composite coiled tubing for running the downhole equipment into the wellbore. The composite coiled tubing string has multiple layers of fibers arranged in a generally cylindrical shape, wherein each layer has a plurality of fibers arranged in a predetermined orientation to form a composite coiled tubing string having sufficient strength to be pushed into and pulled and out of the borehole. A plurality of detectable indicia (such as metallic, magnetic or encoded sections) overlay at least one of the layers of fibers and are integral to the composite coiled tubing string and spaced apart along the length of the tubing string at predetermined distances.

Abstract: Methane gas recovery from wells extending into subterranean coal seams is stimulated by treatment of near-wellbore coal seam with cryogenic liquid.

Abstract: A system for drilling low rate coalbed formations wherein the formation has anisotropic fracture characteristics which create low permeability (high volatile B bituminous rank or lower). Typically these coalbeds have vitrinite reflectance less than 0.78 R.sub.o. The system includes drilling and completing these formation with a horizontal borehole that is drilled with a gas turbine in an underbalanced pressure condition relative to the pressure of the formation. The horizontal borehole is drilled substantially transverse to the general direction of face cleats within the coalbed.

Abstract: A system for centralizing casing pipe in a wellbore includes lateral pistons in the side wall of the casing string which are movable by force applied to their inner end, from a retracted position within the maximum exterior profile of the casing pipe string to a predetermined extended position which will move the casing pipe string toward a central position in the borehole. Various well operations can be performed using the pistons in addition to the centralizing function. When a predetermined deploying force is applied to the pistons, they are released from their retracted position for movement to a fixed extended position. The deploying force is accurately determined by a simple retaining mechanism involving a snap ring and groove on the pistons.

Abstract: This invention relates to a composite torque shaft for connecting a downhole fluid motor to the drill bit at the end of a drill string. The composite torque shaft comprises an elongate matrix body with oriented fibers fixed therein. The fibers are particularly oriented to provide the composite torque shaft with significant torque strength and stiffness while allowing bending flexibility. Accordingly, the composite torque shaft converts the gyrating and rotating motion of the rotor in the fluid motor to the pure rotation of the drill bit.

Abstract: An anisotropically tailored tubular (fabricated of a composite having an unsymmetrical bias of the reinforcing components of the composite and an elasticity of the matrix thereof such that at least one of compression stress along the long axis of the tubular or tension stress along the long axis of the tubular or pressure on the interior of the tubular will cause localized twisting and/or extension and/or bending of the tubular along its long axis) is run into a depth extended aperture while imparting localized twisting and/or extension and/or bending to the tubular along its length during the course of the running by impressing at least one of compression stress along the long axis of the tubular, or tension stress along the long axis of the tubular, or pressure on the interior of the tubular. Frictional resistance to the running is thus decreased by the localized twisting, bending, and/or extension.

Abstract: A system for centralizing casing pipe in a wellbore includes lateral pistons in the side wall of the casing string which are movable by forces applied to their inner end, from a retracted position within the maximum exterior profile of the casing pipe string to a predetermined extended position which will move the casing pipe string toward a central position in the borehole. Various well operations can be performed using the pistons in addition to the centralizing function.

Abstract: Apparatus for mooring attachment of a floating tension leg platform to a subsea anchorage. The apparatus includes a tendon with an enlarged connector on one end, the connector being formed by a frustoconical bearing surface extending away from the end to which it is connected. A connector shroud partially surrounds the frustoconical surface and is connected to it by an elastomeric bearing. An inwardly sloping surface engages a supplementarily sloped surface formed on the attachment receptacle load ring to increase hoop strength. A side-entry bottom receptacle is also disclosed.

Abstract: A borehole system for operating a downhole generator suspended on a composite coiled tubing string. The coiled tubing has at least two separate longitudinal chambers to provide separate flow paths. A fluid is pumped from the surface through one flowpath to drive a downhole turbine powered generator for operating downhole systems. A second flowpath in the tubing is used to return fluids to the surface. The non-metal environment of the composite coiled tubing provides a non-magnetic environment in which to operate wellbore devices. Data is transmitted to the surface by way of a fiber optic conductor.

Abstract: A composite tubular member having an outer cylindrical member containing fibers oriented to resist internal pressure while providing low bending stiffness, an inner smaller centrally located core member located near the neutral axis of the composite tubular member and containing fibers oriented to provide high axial stiffness, high tensile strength and low bending stiffness. One or more web members contain fibers oriented to resist shear stress, and connect the outer cylindrical member and the inner core member to form at least two separate cells within the composite tubular member. The web member forms a major and minor moment of inertia within the tubular member to create a preferred bending direction. Conductors are formed integral to the connecting web member for transmitting energy signals through the tubular member.

Abstract: Ball sealers for flowing into casing perforation holes in a wellbore to selectively seal off those perforations receiving a disproportionately large amount of well treatment fluid being injected through the perforations. The ball sealers (22) are comprised of a spherical outer deformable shell (42) defining a central core portion filled with nondeformable particulate matter (46) which is sized small enough to flow with the shape of the deformable outer shell (42) and large enough so that as it consolidates under the force of fluid flow pressure, it will cause the outer shell to bridge over the perforation opening (18) when the force of fluid flowing into the casing (12) pushes the ball sealer (22) against and into the perforation opening (18).

Abstract: Well tools are run into a well, usually a deviated well, using a composite wireline cable made up of a bundle of parallel slidable composite rods and electrical or optical conductors covered with a flexible protective sheath. The cable is stored on a spool and from there it is run into and retrieved from the well.

Abstract: This invention relates to a downhole activated centralizer for centralizing pipes in a wellbore for the exploration and production of hydrocarbons. The downhole activated centralizers are carried within either the pipe casing or the collars or both and remain generally within the maximum outward profile of the pipe string so as not to interfere with the movement and placement of the pipe string in the wellbore. The pipe string may be rotated, reciprocated and circulated which enhances the ability of the installer to place the pipe string in a deviated or long reach wellbore. Once the pipe string is in place, the centralizers may be deployed by one of several methods such that pistons mounted in openings in the peripheral wall of the pipe string move outwardly with sufficient force to move the pipe string way from the walls of the wellbore sufficient to form a complete annulus for cementing.

Abstract: This invention relates to a method and apparatus for perforating the formation in a wellbore wherein the wellbore is established for the production of hydrocarbons. The formation is perforated by explosive material carried in pistons which are carried within either the pipe casing or the collars or both and remain generally within the maximum outward profile of the pipe string so as not to interfere with the movement and placement of the pipe string in the wellbore. The pipe string may be rotated, reciprocated and circulated which enhances the ability of the installer to place the pipe string in a deviated or long reach wellbore. Once the pipe string is in place, the pistons may be deployed by one of several methods such that pistons mounted in openings in the peripheral wall of the pipe string move outwardly with sufficient force to move the pipe string way from the walls of the wellbore sufficient to form a complete annulus for cementing.