Abstract: A floating rig or structure for drilling in the floor of an ocean using a rotatable tubular includes a seal housing having a rotatable seal connected above a marine riser fixed to the floor of the ocean. The seal rotating with the rotating tubular allows the riser and seal housing to maintain a predetermined pressure in the system that is desirable in underbalanced drilling, gas-liquid mud systems and pressurized mud handling systems. A flexible conduit or hose is used to compensate for the relative movement of the seal housing and the floating structure since the floating structure moves independent of the seal housing. A method for use of the system is also disclosed.

Abstract: An apparatus for controlling a subsea borehole fluid pressure is proposed for use with a conductor casing positioned below the mudline and within a normal pore pressure environment. The apparatus includes a pump for moving a fluid through a tubular into a borehole. The fluid, before being pumped, exerts a pressure less than the pore pressure of an abnormal pore pressure environment. The fluid in the borehole is then pressurized by the pump to at least a borehole pressure equal to or greater than the pore pressure of an abnormal pore pressure environment. A pressure housing assembly allows for the drilling of a borehole below the conductor casing into an abnormal pore pressure environment while maintaining the pressurized fluid between a borehole pressure equal to or greater than the pore pressure of the abnormal pore pressure environment, and below the fracture pressure of the borehole in the abnormal pore pressure environment.

Abstract: A pump drive head backspin retarder includes a vane pump having an impeller with a plurality of spring loaded vanes and a pawl clutch centrally disposed in the impeller and having a hub and a plurality of pawls. Each pawl is pivotally attached to the hub for movement between first and second positions. The impeller includes a plurality of pawl receiving recesses, whereby, for a first direction of rotation, pawls of the pawl clutch pivot to the first position corresponding to a disengaged state for providing no mechanical contact with the impeller and, for a second direction of rotation opposite the first, pawls of the pawl clutch pivot to the second position due to inertia corresponding to an engaged state thereby engaging corresponding pawl receiving recesses.

Abstract: A right angle drive adapter for use with an oil well vertical drive head having a drive head housing and an input shaft rotatably mounted in and extending axially outwardly of the drive head housing. The adapter comprises an adapter housing removably securable to the drive head housing in axial alignment therewith, an input shaft mounted in the adapter housing for rotation therein and for removable attachment to a rotary source of power, an output shaft mounted in the adapter housing for rotation therein at substantially a right angle to the input shaft, the output shaft having a socket for telescopically receiving and drivingly connecting to the drive head input shaft; and a gearset mounted in the housing for drivingly connecting the input and output shafts. The adapter allows the installation of a vertical drive head and a gas engine to be used for driving the drive head before electrical power is available.

Abstract: A pump drive head includes a housing, and a main shaft carried on upper and lower bearings disposed in the housing. The main shaft includes an outer torque tube and a liner tube. The outer and liner tubes abut along a first portion of their length and are separated along a second portion of their length forming a double wall with an elongate tubular space in between. A standpipe is coupled at one end to the housing, below the lower bearing, and received by the elongate tubular space an eliminates the need for a lower seal on the main shaft. A hydraulic pump includes a hydraulic pump chamber displosed in the housing and communicating with the main shaft, and first and second gears disposed in the hydraulic pump chamber and the first gear coupled to the main shaft. The second gear intermeshes with the first gear. A suction port is located between the first and second gears and operable when the main shaft is rotated in a reverse direction from the normal pumping direction, during a condition known as backspin.

Abstract: A backspin retarder for a shaft comprises a brake mechanism including a stationary brake member and opposed brake members rotatable with the shaft and movable between braking position in which the movable brake members engage the stationary brake member and a non-braking position in which the movable brake members are removed from the stationary brake member and a brake control mechanism responsive to the direction of rotation of the shaft for disabling the brake mechanism when the shaft rotates in a forward direction and for enabling the brake mechanism when the shaft rotates in a reverse direction.