A REVERSE CIRCULATING TOOL FOR CLEANING A WELL

摘要

A tool and method for circulating fluid within a borehole wherein fluid is passed down an annulus between the tool and the borehole, the fluid being returned to the surface through the tool whereby it may be recycled. The tool typically includes a cavity in which particles of dirt, drill cuttings or the like are collected. The tool may also include a filter to prevent larger particles of dirt etc. from continuing upward to the surface. The tool may also include a trap to prevent particles of dirt etc. from returning into the borehole from the tool.