Abstract: A method for assembling and delivering a drivepipe to a drill site. The method has the following steps: The drivepipe is assembled at a shoreline assembly station. Floatation devices are attached to the drivepipe and the drivepipe is floated in the ocean. The drivepipe is towed with tow vessels to a drill site. The drivepipe is delivered in a horizontal orientation to a drilling vessel at the drill site. An upper end of the drivepipe is attached to the drilling vessel and the tow vessels are detached from the drivepipe. The drivepipe is pivoted about its point of attachment to the drilling vessel until the drivepipe is vertically oriented. The buoyancy function of the floatation devices attached to the drivepipe is deactivated. The floatation devices are removed from the drivepipe. The drivepipe is equipped with a driving mechanism and the drivepipe is lowered with a running string from the drilling vessel to the sea bed.

Abstract: A method for driving a drive pipe into a subsea formation, the method being comprised of the following steps: suspending the drive pipe from a drill string; moving at least one mass in a direction having an upward component and within the drive pipe; accelerating at least one mass relative to the drive pipe, wherein the at least one mass is accelerated within the drive pipe; transferring energy from the accelerated at least one mass to the drive pipe; isolating the drill string from energy from the accelerated at least one mass; and removing a core of formation from within the drive pipe after the transferring.

Abstract: A method for assembling and delivering a drivepipe to a drill site, the method having the following steps: assembling the drivepipe at a shoreline assembly station; attaching floatation devices to the drivepipe and floating the drivepipe in the ocean; towing the drivepipe with tow vessels to a drill site; delivering the drivepipe in a horizontal orientation to a drilling vessel at the drill site; attaching a upper end of the drivepipe to the drilling vessel and detaching the tow vessels from the drivepipe; pivoting the drivepipe about its point of attachment to the drilling vessel until the drivepipe is vertically oriented; deactivating the buoyancy function of the floatation devices attached to the drivepipe; removing the floatation devices from the drivepipe; equipping the drivepipe with a driving mechanism; and lowering the drivepipe with a running string from the drilling vessel to the sea bed.

Abstract: A method for assembling and delivering a drivepipe to a drill site, the method having the following steps: assembling the drivepipe and driving mechanism at a shoreline assembly station; attaching floatation devices to the drivepipe and floating the drivepipe in the ocean; towing the drivepipe with tow vessels to a drill site; delivering the drivepipe in a horizontal orientation to a drilling vessel at the drill site; attaching a upper end of the drivepipe to the drilling vessel and detaching the tow vessels from the drivepipe; pivoting the drivepipe about its point of attachment to the drilling vessel until the drivepipe is vertically oriented; deactivating the buoyancy function of the floatation devices attached to the drivepipe; removing the floatation devices from the drivepipe; and lowering the drivepipe with a running string from the drilling vessel to the sea bed.

Abstract: There is disclosed a single-acting hydraulic jar having upper and lower detent pressure chambers having upper and lower restrictions, respectively, formed on the inner diameter of its outer tubular member and through which upper and lower detent means carried about the outer diameter of the inner tubular member may be moved in order to impart an up jar.

Abstract: There is disclosed a double-acting hydraulic jar having upper and lower detent pressure chambers having upper and lower restrictions, respectively, formed on the inner diameter of its outer tubular member and through which upper and lower detent means carried about the outer diameter of the inner tubular member may be moved in order to impart either an up or down jar.

Abstract: There is disclosed a tool for enhancing the impact of a jar delivered to an object stuck in a well bore during both upward and downward jars to the stuck object. The tool includes a first tubular member having an lower end connectible to the tubular member of the jar on which the hammer is mounted and a second tubular member connectible to a well pipe string above it and arranged for reciprocation with respect to the first member to form an annular space between them. The space is divided into upper and lower chambers by means of seal rings disposed between the members and the spaces are filled with a compressible fluid which is compressed as the second tubular member is moved in either upward or downward directions.

Abstract: There is disclosed a tool for enhancing the impact delivered to an object stuck in a well bore by means of a jar having a first tubular member connected to the object and a second tubular member having a hammer arranged to deliver an upward blow to an anvil on the first member in response to raising and a downward blow in response to lowering of the second tubular mandrel member with respect to the first member, the tool comprising a first tubular member having a lower end adapted to be connected to the second tubular member of the jar for raising and lowering therewith, a second tubular member vertically reciprocable with respect to the first member to form on annular space between them and having an upper end adapted to be connected to a well pipe string above it, and first and second sets of upper and lower longitudinally spaced seal rings within the annular space and sealably slidable with respect to equal diameter portions of each of the tubular members to form upper and lower fluid chambers between the

Abstract: An apparatus for use in transmitting torque between a first part rotatable about a fixed axis and a second part rotatable in a circular path about the axis, and which includes a torque bar having its ends connected to ends of the parts by universal joints.

Abstract: There are disclosed alternate embodiments of a double acting hydraulic jar having a single detent chamber having a restriction on the inner diameter of its outer tubular member through which detent means carried about the outer diameter of the inner tubular member may be moved in order to impart either an up or down jar.