Patent ID: 7160474

Claim:
A method for recycling drilling fluid containing solids, comprising: a) directing a stream of drilling fluid containing solids into a substantially vertical flow-reversing barrier located in a receiving compartment of a settling tank, the settling tank further comprising a collecting compartment, the collecting compartment separated from the receiving compartment by a transverse wall, the wall defining an aperture with a flow-restricting baffle attached thereto and extending perpendicular from the wall into the collecting compartment, the flow-reversing barrier capable of causing the stream to reverse direction and flow around the barrier thereby causing at least some of the solids contained in the fluid to settle to the bottom of the tank; b) allowing the stream of fluid to fill the receiving compartment and pass through the aperture and flow-restricting baffle of the transverse wall as the fluid flows in a first direction from the receiving compartment to the collecting compartment, the flow-restricting baffle capable of causing at least some of the remaining solids contained in the fluid to settle to the bottom of the tank as the fluid flows through the aperture and baffle; c) allowing the fluid to flow in the first direction and fill the collecting compartment; d) extracting fluid from the collecting compartment for re-use in drilling operations; e) moving the settled solids on the bottom of the tank in the first direction towards an outlet located in the collecting compartment; and f) removing a mixture of fluid and solids from the outlet.