DRILLING FLUID RECOVERY WHEN DRILLING UNDER AN OBSTACLE OR WATER BODY

摘要

A system for recovering drilling mud in drilling an underground arcuate path around at least a portion of an obstacle has a conductor casing, a drill pipe surrounded by the conductor casing for at least a portion of an axial length of the drill pipe, a flow line connected to the conductor casing at a downhole position, and a pump coupled to the flow line placed at another downhole position. A volume of drilling mud within the underground arcuate path is pumped from the underground arcuate path to the surface and recovered for recirculation.