Subsea pumping system and method for deepwater drilling
AssigneeShell Offshore Inc.
InventorRomulo Gonzalez
Life of this patent
Estimating the term…
Abstract
A method is disclosed for offshore drilling in which a bit is driven at a far end of a drill string, drilling fluid is injected into the drill string from surface drilling facilities, and drilling fluid passes through the far end of the drill string and flushes the borehole at the bit and entrains cuttings into the drilling fluid which circulates up the casing/drill string annulus. The drilling fluid drawn off near the mudline and is treated through a subsea primary processing stage to removing the cuttings from the drilling fluid. The treated drilling fluid is then returned to the surface with a subsea return pump system and passes to surface drilling facilities for injection and recirculation.
Claims55
A method for offshore drilling comprising:
- driving a bit mounted at a far end of a drill string;
- injecting a drilling fluid into the drill string from surface drilling facilities;
- flushing the borehole at the bit and entraining cuttings into the drilling fluid;
- treating the drilling fluid through a subsea primary processing stage and thereby removing the cuttings from the drilling fluid;
- and
- returning the treated drilling fluid to the surface with a subsea return pump system.
An offshore drilling system comprising:
- a drill string;
- a bit at the far end of the drill string;
- a blow out preventor mounted on a well head near the sea floor through which the drill string passes;
- a drilling fluid injected into the drill string from surface drilling facilities;
- a mud return line above the blow out preventor to receive the drilling fluid and entrained cuttings substantially at the sea floor;
- a subsea primary processing stage connected to the mud return line for treating the drilling fluid by removing the cuttings from the drilling fluid in a subsea operation;
- a subsea return pump system receiving the treated drilling fluid;
- and
- a return line through which the treated drilling fluid is returned to the surface.
A method for offshore drilling comprising:
- driving a bit mounted at a far end of a drill string;
- injecting a drilling fluid into the drill string from surface drilling facilities;
- flushing the borehole at the bit and entraining cuttings into the drilling fluid;
- treating the drilling fluid through a subsea primary processing stage and thereby removing the cuttings from the drilling fluid, comprising:
- passing the drilling fluid into an ambient pressure gas chamber near the sea floor through a weir;
- separating the cuttings at gumbo rails and passing the drilling fluid to a collection basin;
- and
- transporting the cuttings away from the subsea facilities for disposal;
- returning the treated drilling fluid to the surface with a subsea return pump system;
- and
- passing the returned drilling fluid to surface drilling facilities for reinjection.
A method for offshore drilling comprising:
- driving a bit mounted at a far end of a drill string;
- injecting a drilling fluid into the drill string from surface drilling facilities;
- passing the drilling fluid through a drill string shut-off valve at the far end of the drill string;
- flushing the borehole at the bit and entraining cuttings into the drilling fluid;
- treating the drilling fluid through a subsea primary processing stage and thereby removing the cuttings from the drilling fluid, comprising:
- passing the drilling fluid into an ambient pressure gas chamber near the sea floor through a weir;
- separating the cuttings at gumbo rails and passing the drilling fluid to a collection basin;
- and
- transporting the cuttings away from the subsea facilities for disposal;
- returning the treated drilling fluid to the surface with a subsea return pump system;
- and
- passing the returned drilling fluid to surface drilling facilities for reinjection.
An offshore drilling system comprising:
- a drill string;
- a drill string shut-off valve at the far end of the drill string;
- a bit at the far end of the drill string, below the drill string shut-off valve;
- a blow out preventor mounted on a well head near the sea floor through which the drill string passes;
- a drilling fluid injected into the drill string from surface drilling facilities;
- a mud return line above the blow out preventor to receive the drilling fluid and entrained cuttings substantially at the sea floor;
- a subsea primary processing stage connected to the mud return line for treating the drilling fluid by removing the cuttings from the drilling fluid in a subsea operation;
- a subsea return pump system receiving the treated drilling fluid;
- and
- a return line through which the treated drilling fluid is returned to the surface.
Dependencies are inferred from the claim text.