Development and analysis of core catchers

Abstract:

Compared with conventional coring technology, when drilling in loose, soft, broken and other complex formation, core catching technology can obtain higher core recovery. The core catching tool developed at home and abroad mainly includes double-tube rigid type, double-tube swivel type and wireline core-catching drilling tools. The key points indevelopment of the tools mainly include the design of the core catcher structure and the choice of the loading mode. Development of the core drilling tools shows thatthe core catcher with the triangle slipshas good closing performance and hydraulic loadingcan be accurately controlled to achievethe core breaking force. Wireline core-catching drilling tools have high drilling efficiency, but the development is relatively difficult. In this paper, the structural characteristics and coring operation procedure of the core-catching drilling tools at home and abroad are described in detail. The design advantages and disadvantages are analyzed and the development trend is put forward. All these lay a foundation for the optimum design of core-catchingdrilling tool.