Abstract: A flowbore fluid temperature control system comprising a valve mechanism that adjusts the flow of a fluid through a flowbore. The flowbore fluid temperature control system also comprises an actuator that adjusts the valve mechanism. The flowbore fluid temperature control system also comprises an operating system that operates the actuator and controls the flowbore fluid pressure. The flowbore fluid temperature control system selectively controls the temperature of the flowbore fluid by adjusting the flow of the fluid through the flowbore. The control system controls the actuator and also controls the flowbore fluid pressure to affect the temperature of the flowbore fluid.

Abstract: Methods and apparatus for monitoring and controlling the pressure in a wellbore characterized by a drilling system utilizing real-time bottom hole pressure measurements and a control system adapted to control parameters such as well shut-in, drilling fluid weight, pumping rate, and choke actuation. In the preferred embodiments, the control system receives input from the bottom hole pressure sensor as well as pressure sensors, mud volume sensors, and flowmeters located at the surface. The control system then adjusts one or more of drilling fluid density, pumping rate, or choke actuation to detect, shut-in, and circulate out wellbore influxes. The preferred system operates automatically without any manual intervention in well control processes.

Abstract: Methods and apparatus are disclosed for the open hole drilling of a borehole from an offshore platform and through a cased borehole at the seafloor. The drilling assembly includes a guide assembly extending from the platform to the seafloor and having a lower end extending into the cased borehole; and a bottomhole assembly disposed on a lightweight drill string extending through the guide assembly for drilling the borehole. The guide assembly is a pipe string and preferably includes a casing and a riser attached to the casing. The lightweight drill string may be a jointed pipe, a metal coiled tubing, or preferably a composite coiled tubing. The bottomhole assembly includes a formation displacement member adapted to drill a borehole having a diameter greater than the diameter of the guide assembly.

Abstract: Methods and apparatus for drilling subsea wells in deep water using dual-gradient drilling techniques. One preferred embodiment includes a high pressure riser running from a drilling platform at the surface to the seafloor. The base of the riser is connected to a wellhead that is anchored to the seafloor. Pressure control equipment is disposed on the upper end of the riser at the drilling platform. A coiled tubing drill string is run through the riser and into the subsea formation. The drill string preferably includes a pressure sensing device that can be used in transmitting real-time downhole pressure data to the surface. A riser injection system is provided to inject a lower density fluid into the riser annulus in order to reduce the density of the fluids in the riser annulus and therefore reduce the hydrostatic pressure within the wellbore.

Abstract: Methods and apparatus for monitoring and controlling the pressure in a wellbore characterized by a drilling system utilizing real-time bottom hole pressure measurements and a control system adapted to control parameters such as well shut-in, drilling fluid weight, pumping rate, and choke actuation. In the preferred embodiments, the control system receives input from the bottom hole pressure sensor as well as pressure sensors, mud volume sensors, and flowmeters located at the surface. The control system then adjusts one or more of drilling fluid density, pumping rate, or choke actuation to detect, shut-in, and circulate out wellbore influxes. The preferred system operates automatically without any manual intervention in well control processes.

Abstract: Methods and apparatus are disclosed for the open hole drilling of a borehole from an offshore platform and through a cased borehole at the seafloor. The drilling assembly includes a guide assembly extending from the platform to the seafloor and having a lower end extending into the cased borehole; and a bottomhole assembly disposed on a lightweight drill string extending through the guide assembly for drilling the borehole. The guide assembly is a pipe string and preferably includes a casing and a riser attached to the casing. The lightweight drill string may be a jointed pipe, a metal coiled tubing, or preferably a composite coiled tubing. The bottomhole assembly includes a formation displacement member adapted to drill a borehole having a diameter greater than the diameter of the guide assembly.