Abstract: A subsea drilling method for controlling the bottom hole annular pressure and downward injection rate during mud cap drilling operations from a mobile offshore drilling unit with a low pressure marine riser and subsea blowout preventer. The method called controlled mud cap drilling uses the hydrostatic head of a heavy annular mud (fluid) managed or observed in order to balance the highest pore pressure in the well and to control the injection rate, by using a subsea mud lift pump and a control system to regulate the process.

Abstract: A subsea drilling method for controlling the bottom hole annular pressure and downward injection rate during mud cap drilling operations from a mobile offshore drilling unit with a low pressure marine riser and subsea blowout preventer. The method called controlled mud cap drilling uses the hydrostatic head of a heavy annular mud (fluid) managed or observed in order to balance the highest pore pressure in the well and to control the injection rate, by using a subsea mud lift pump and a control system to regulate the process.

Abstract: A subsea drilling method for controlling the bottom hole annular pressure and downward injection rate during mud cap drilling operations from a mobile offshore drilling unit with a low pressure marine riser and subsea blowout preventer. The method called controlled mud cap drilling uses the hydrostatic head of a heavy annular mud (fluid) managed or observed in order to balance the highest pore pressure in the well and to control the injection rate, by using a subsea mud lift pump and a control system to regulate the process.

Abstract: A subsea drilling method for controlling the bottom hole annular pressure and downward injection rate during mud cap drilling operations from a mobile offshore drilling unit with a low pressure marine riser and subsea blowout preventer. The method called controlled mud cap drilling uses the hydrostatic head of a heavy annular mud (fluid) managed or observed in order to balance the highest pore pressure in the well and to control the injection rate, by using a subsea mud lift pump and a control system to regulate the process.

Abstract: A subsea drilling method and system controls drilling fluid pressure in the borehole of a subsea well, and separates gas from the drilling fluid. Drilling fluid is pumped into the borehole through a drill string and returned through an annulus between the drill string and the well bore and between the drill string and a riser. Drilling fluid pressure is controlled by draining fluid out of the riser or a BOP at a level between the seabed and the surface in order to adjust the hydrostatic head of drilling fluid in the riser. The drained drilling fluid and gas is separated in a subsea separator, where the gas is vented to the surface through a vent line, and the fluid is pumped to the surface via a subsea pump. A closing device and a choke line and valve can release pressure after a gas kick in the well.

Abstract: A subsea drilling method and system controls drilling fluid pressure in the borehole of a subsea well, and separates gas from the drilling fluid. Drilling fluid is pumped into the borehole through a drill string and returned through an annulus between the drill string and the well bore and between the drill string and a riser. Drilling fluid pressure is controlled by draining fluid out of the riser or a BOP at a level between the seabed and the surface in order to adjust the hydrostatic head of drilling fluid in the riser. The drained drilling fluid and gas is separated in a subsea separator, where the gas is vented to the surface through a vent line, and the fluid is pumped to the surface via a subsea pump. A closing device and a choke line and valve can release pressure after a gas kick in the well.

Abstract: A subsea drilling method and system controls drilling fluid pressure in the borehole of a subsea well, and separates gas from the drilling fluid. Drilling fluid is pumped into the borehole through a drill string and returned through an annulus between the drill string and the well bore and between the drill string and a riser. Drilling fluid pressure is controlled by draining fluid out of the riser or a BOP at a level between the seabed and the surface in order to adjust the hydrostatic head of drilling fluid in the riser. The drained drilling fluid and gas is separated in a subsea separator, where the gas is vented to the surface through a vent line, and the fluid is pumped to the surface via a subsea pump. A closing device and a choke line and valve can release pressure after a gas kick in the well.

Abstract: A subsea mud pump can be used to return heavy drilling fluid to the surface. In order to provide a less stringent requirement for such a pump and to better manage the bottom hole pressure in the case of a gas kick or well control event, the gas should be separated from the drilling fluid before the drilling fluid enters the subsea mud pump and the pressure within the separating chamber. The mud pump suction should be controlled and kept equal or lower than the ambient seawater pressure. This can be achieved within the cavities of the subsea BOP by a system arrangement and methods explained. This function can be used with or without a drilling riser connecting the subsea BOP to a drilling unit above the body of water.

Abstract: A subsea drilling method and system controls drilling fluid pressure in the borehole of a subsea well, and separates gas from the drilling fluid. Drilling fluid is pumped into the borehole through a drill string and returned through an annulus between the drill string and the well bore and between the drill string and a riser. Drilling fluid pressure is controlled by draining fluid out of the riser or a BOP at a level between the seabed and the surface in order to adjust the hydrostatic head of drilling fluid in the riser. The drained drilling fluid and gas is separated in a subsea separator, where the gas is vented to the surface through a vent line, and the fluid is pumped to the surface via a subsea pump. A closing device and a choke line and valve can release pressure after a gas kick in the well.

Abstract: An apparatus for controlling tension in a wireline (4), the apparatus comprising a reel (3) mounted on a vessel or surface platform for controlling a wire in a wireline operation, a primary drive means (5) between the reel and a subsea installation around which the wireline is wound and control means for synchronizing the operation of the driver with the reel.

Abstract: A subsea drilling method and system for controlling the drilling fluid pressure, where drilling fluid is pumped down into the borehole through a drill string and returned back through the annulus between the drill string and the well bore. The drilling fluid pressure is controlled by draining drilling fluid out of the drilling riser (8) or BOP (6) at a level between the seabed and the sea water in order to adjust the hydrostatic head of drilling fluid. The drained drilling fluid and gas is separated in a subsea separator (28) where the gas is vented to surface through a vent line (39), and the fluid is pumped to surface via pump (40).

Abstract: An arrangement and a method to control and regulate the bottom hole pressure in a well during subsea drilling at deep waters: The method involves adjustment of a liquid/gas interface level in a drilling riser up or down. The arrangement comprises a high pressure drilling riser and a surface BOP at the upper end of the drilling riser. The surface BOP has a gas bleeding outlet. The riser also comprises a BOP, with a by-pass line. The drilling riser has an outlet at a depth below the water surface, and the outlet is connected to a pumping system with a flow return conduit running back to a drilling vessel/platform.

Abstract: A subsea mud pump can be used to return heavy drilling fluid to the surface. In order to provide a less stringent requirement for such a pump and to better manage the bottom hole pressure in the case of a gas kick or well control event, the gas should be separated from the drilling fluid before the drilling fluid enters the subsea mud pump and the pressure within the separating chamber. The mud pump suction should be controlled and kept equal or lower than the ambient seawater pressure. This can be achieved within the cavities of the subsea BOP by a system arrangement and methods explained. This function can be used with or without a drilling riser connecting the subsea BOP to a drilling unit above the body of water.

Abstract: An arrangement and a method to control and regulate the bottom hole pressure in a well during subsea drilling at deep waters: The method involves adjustment of a liquid/gas interface level in a drilling riser up or down. The arrangement comprises a high pressure drilling riser and a surface BOP at the upper end of the drilling riser. The surface BOP has a gas bleeding outlet. The riser also comprises a BOP, with a by-pass line. The drilling riser has an outlet at a depth below the water surface, and the outlet is connected to a pumping system with a flow return conduit running back to a drilling vessel/platform.

Abstract: A method for removing soils, particles or fluids from the seabed or from great sea depths, includes positioning a platform or a vessel above an offshore location, lowering a riser from the vessel or platform to the seabed or great depth, the riser being vented to the atmosphere, sucking soils, particles or fluids with inflow of fluid into the riser and removing them from the riser via an outlet in the riser, the outlet being at a level well below the water surface, by use of a pumping system with a flow return conduit running to a selected location, while keeping the level of the fluid in the riser at a level between the outlet and the surface corresponding with a pressure in the lower end of the riser substantially lower than the sea water pressure at the end of the riser.

Abstract: A subsea drilling method and system for controlling the drilling fluid pressure, where drilling fluid is pumped down into the borehole through a drill string and returned back through the annulus between the drill string and the well bore. The drilling fluid pressure is controlled by draining drilling fluid out of the drilling riser (8) or BOP (6) at a level between the seabed and the sea water in order to adjust the hydrostatic head of drilling fluid. The drained drilling fluid and gas is separated in a subsea separator (28) where the gas is vented to surface through a vent line (39), and the fluid is pumped to surface via pump (40).

Abstract: An apparatus for controlling tension in a wireline (4), the apparatus comprising a reel (3) mounted on a vessel or surface platform for controlling a wire in a wireline operation, a primary drive means (5) between the reel and a subsea installation around which the wireline is wound and control means for synchronising the operation of the driver with the reel.

Abstract: A method for removing soils, particles or fluids from the seabed or from great sea depths, includes positioning a platform or a vessel above an offshore location, lowering a riser from the vessel or platform to the seabed or great depth, the riser being vented to the atmosphere, sucking soils, particles or fluids with inflow of fluid into the riser and removing them from the riser via an outlet in the riser, the outlet being at a level well below the water surface, by use of a pumping system with a flow return conduit running to a selected location, while keeping the level of the fluid in the riser at a level between the outlet and the surface corresponding with a pressure in the lower end of the riser substantially lower than the sea water pressure at the end of the riser.

Abstract: An arrangement and a method to control and regulate the bottom hole pressure in a well during subsea drilling at deep waters: The method involves adjustment of a liquid/air interface level in a drilling riser. The arrangement comprises a drilling riser with an outlet at a depth below the water surface. The outlet is connected to a subsea pumping system with a flow return conduit back to a drilling vessel. The intention of the system is to transport the drilling fluid and the formation particles to the surface on the drilling unit prior to setting structural pipe on the seabed and when drilling at least one hole section after the first surface structural casing have been set. The apparatus is used in order to drill all surface hole sections with the riser installed in order to avoid “pump & dump” procedures and to recover all mud and chemicals.

Abstract: An arrangement and a method to control and regulate the bottom hole pressure in a well during subsea drilling at deep waters: The method involves adjustment of a liquid/gas interface level in a drilling riser up or down. The arrangement comprises a high pressure drilling riser and a surface BOP at the upper end of the drilling riser. The surface BOP havs a gas bleeding outlet. The riser also comprises a BOP, with a by-pass line. The drilling riser has an outlet at a depth below the water surface, and the outlet is connected to a pumping system with a flow return conduit running back to a drilling vessel/platform.