Research status and prospects of coring tools for broken formation

Abstract:

Experts and scholars at home and abroad have conducted lots of research on coring in broken formation for many decades, leading to notable resultsin terms of decreasing core entry resistance, increasing core recovery, extending footage per run, increasing ROP, etc. However, less research has been made on solutions to core jamming incidents. To some extent the jam-releasing coring tools represented by JamBuster alleviated the core plugging problem, and extended the footage per round by adding liners, but the problem of core jamming hasn’t been fundamentally solved. This paper summarizes the research state of the special coring tools and technologies for broken formations in the past, analyses their shortcomings, and puts forward some suggestions for improvement.