Design and application of bag-type coring tool

How to improve the coring recovery rate is one of the important problems of concern in drilling engineering, this paper describes the design of a bag-type double-barreled coring tool for engineering survey and geological drilling. This coring tool can use the plastic bags in the double-barreled structure to keep coring recovery rate in very broken, easy washout, very soft, water sensitive stratum. Under precondition of using double-barreled coring tool without adding other drilling equipment, the core recovery rate reaches above 90%.