Drilling fluid circulation system
AssigneeConoco Inc.
InventorsPramod C. Thakur, Charles E. Mason, Stephen D. Lauer, Emrys H. Jones, Jr.
Life of this patent
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Abstract
A drilling fluid circulation system for containing drilling cuttings, gas and drilling fluid in a closed loop. The system includes a separator having two sealed compartments, one for settling out drilling cuttings and one for holding clean drilling fluid. A fine solids separator is provided between the two compartments, and a gas exhaust line for conducting gas released from the returning drilling fluid is provided to conduct the produced gas to a safe location away from the working area. A solids discharge device is provided for removing settled drilling cuttings.
Claims6
In a drilling system comprising (1) a drill unit for drilling from an underground room and for providing horizontal thrust to a drill bit, and (2) a drilling fluid circulation system for providing liquid drilling fluid through a drill string to a drill bit and for returning said fluid, cuttings and produced gas through a borehole to a gas and cuttings separation system, the improvement wherein said gas and cuttings separation system is a closed loop system comprising:
- (a) a first compartment for storing clean liquid drilling fluid;
- (b) a second compartment having an inlet for receiving drilling fluid, drilling cuttings and produced gas from said drilling fluid circulation system and said second compartment including a plurality of baffles therein;
- (c) connecting means between said first and second compartments, said connecting means including fluid passage means allowing liquid drilling fluid to flow from said second compartment to said first compartment;
- (d) liquid level control means for maintaining a minimum liquid level in said compartments;
- (e) liquid level control means for limiting the upper level of liquid in said compartments;
- (f) gas-containing sections in the upper part of said compartments;
- (g) gas communication means providing for free passage of gas between the said gas-containing sections;
- (h) gas exhaust means for removing gas from said gas-containing sections and exhausting it at a location outside said underground room;
- (i) cuttings removal means comprising an auger positioned in the bottom of said second compartment and including a cuttings discharge outlet for removing settled cuttings from said second compartment;
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- (j) outlet means for returning said liquid drilling fluid to said drilling fluid circulation system.
Dependencies are inferred from the claim text.