Hydril Company

Varco Shaffer, Inc.

Vareo Shaffer, Inc.

Hubert L Elkins

Mark A Merit

Joseph H Hynes

James A Burton

James Dennis Brugman

Milton E Goodhart

Methods and systems are provided for drilling a well bore 60 through a subterranean formation using a drilling rig 25 and a drill string 50, whereby the bottom hole pressure while circulating drilling fluid (&ldquo;ECD&rdquo;) may be substantially maintained when circulation is interrupted or altered, such as when adding a joint of drill pipe to or removing a joint of drill pipe from the drill string. The method includes controllably applying and maintaining a desired variable annulus fluid pressure in the well bore, and thereafter controllably releasing the pressure from the well bore 60. In addition, methods and systems are provided for rotating the drill string while trapping, maintaining and/or releasing the well bore pressure. A substantially constant ECD pressure may be maintained on a formation, thereby facilitating the use of a lower density drilling fluid than may otherwise be required to maintain well control. In one embodiment, a drill pipe connection may be made up and/or broke out while the drill string continues to rotate.

Well drilling method and system

Methods and systems are provided for drilling a well bore through a subterranean formation using a drilling rig and a drill string whereby the bottom hole pressure while circulating drilling fluid (&ldquo;ECD&rdquo;) may be substantially maintained when circulation is interrupted or altered, such as when adding a joint of drill pipe to or removing a joint of drill pipe from the drill string. The method includes controllably applying and maintaining a desired variable annulus fluid pressure in the well bore, and thereafter controllably releasing the pressure from the well bore In addition, methods and systems are provided for rotating the drill string while trapping, maintaining and/or releasing the well bore pressure. A substantially constant ECD pressure may be maintained on a formation, thereby facilitating the use of a lower density drilling fluid than may otherwise be required to maintain well control. In one embodiment, a drill pipe connection may be made up and/or broke out while the drill string continues to rotate.

A subsea hydraulic control system,supplies hydraulic fluid to operate subsea equipment SE, which in exemplary application may be a blowout preventer having an opening port and a closing port. A hydraulic control system includes a fluid storage vessel,for storing a selected quantity of hydraulic fluid, and a separation member,separating subsea water from hydraulic fluid while pressurizing the hydraulic fluid in response to the hydrostatic head of the water. A fluid supply line,interconnects the fluid storage vessel and the subsea equipment, and a fluid exhaust line,interconnects the subsea equipment with a subsea hydraulic fluid reservoir vessel,. A vent line,extends from the fluid reservoir vessel to the surface. A subsea pump periodically exhausts fluid from the fluid storage vessel to the water. The method of the invention provides reliable actuation of subsea equipment, and is particularly well suited for operating subsea equipment in deep water at depths in excess of 6,000 feet.

Subsea hydraulic control system

A method and apparatus is disclosed for controlling a well drilled from a floating drilling vessel during the time that the marine riser is removed and conductor casing is being lowered and cemented into the well. An annular blowout preventer having a bore substantially equal to that of the structural casing is provided in a stack above the structural casing wellhead housing. A kill line is provided to the drilling vessel and is connected to the wellbore conduit below the blowout preventer. A marine riser is attached to the top of the blowout preventer through which the hole to be lined with conductor casing is drilled. The well is established to a depth of about one thousand (1000) feet below the seabed. The annular blowout preventer is closed, the marine riser is removed, and a stripper and guidance assembly is landed on the top of the blowout preventer in preparation for lowering the conductor casing in the well. The conductor casing, with a second wellhead housing attached to the top thereof, is stripped into the well, the second wellhead housing landing within the structural casing wellhead housing. The conductor casing is then cemented in the hole. Well pressure is monitored by means of a surface disposed pressure gauge attached to the top of the kill line. Excess well pressure is relieved by means of the kill line or by means of a vent valve provided in the structural casing wellhead housing.

Well control method and apparatus

A method and apparatus is disclosed for deviated hole drilling upwardly and outwardly from beneath a shallow hydrocarbon formation pay zone. A large diameter vertical hole is first formed as by drilling below the pay zone. A first casing having a directional window provided in its wall is cemented in the large diameter hole. One or more casings are then provided in the borehole below the first casing. A carriage assembly loaded with drilling tools for drilling upwardly and outwardly is then lowered by means of a working drill string and landed within the first casing. The carriage assembly has a first passage in fluid communication with the drill string. The drilling tools are loaded within a second passage of the carriage assembly. The top opening of the second passage is below the directional window when the carriage assembly is landed and angularly oriented in the first casing. A drill string extends from the drilling tools through the bottom of the carriage assembly and into the cased hole below the first casing. A stripper packer assembly at the lower end of the carriage assembly prevents the incoming high pressure mud from entering the second passage of the carriage assembly. The drilling tools comprise a mud pressure driven motor for turning a drilling bit. A weight-on-bit assembly provides force to the drilling bit against the face of the borehole being drilled. A bent sub causes the drilling to be deviated outwardly while drilling upwardly. Drilling power is provided via pressurized mud through the working drill string, the first passage, the annulus between the lower hole casing and the outside of the drilling string and then via the interior of the drill string.

Method and apparatus for forming boreholes

A method and apparatus is disclosed for controlling a well drilled from a floating drilling vessel during the time that the marine riser is removed and conductor casing is being lowered and cemented into the well. An annular blowout preventer having a bore substantially equal to that of the structural casing is provided in a stack above the structural casing wellhead. A kill line is provided to the drilling vessel and is connected to the wellbore conduit below the blowout preventer. A spool is attached to the top of the blowout preventer. A casing stripper is attached to the top of the spool and has a mandrel extending from its top about which a wellhead connector attached to the marine riser system is connected. The marine riser system includes a flow diverter at its top disposed on the drilling vessel. The hole to be lined with conductor casing is drilled through the marine riser to a depth of about one thousand (1000) feet below the sea bed. The annular blowout preventer is then closed, the riser system removed, and conductor casing is guided to the mouth of the mandrel atop the casing stripper. The conductor casing is then lowered into the spool and the blowout preventer is opened. The conductor casing, with a second wellhead attached to the top thereof, is stripped into the well, the second wellhead landing within the structural casing wellhead. The conductor casing is then cemented in the hole. Well pressure is monitored by means of a surface disposed pressure gauge attached to the top of the kill line. Excess well pressure is relieved by means of the kill line or by means of a vent valve provided in the structural casing wellhead housing.

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Kingwood, TX, United States of America

Hubert L Elkins