Development of wire-line drilling tools for complex formation

Abstract:

Using the conventional wire-line drilling tool in complex formation always leads to low core recovery. There are two main causes: firstly, because of poor waterproofness of the conventional wire-line drilling tool, the core is eroded by flushing fluid before entering the core barrel during drilling in loose soft formation; secondly, it has poor performance in preventing core loss in hard, brittle, broken formation since the core lifter cannot lock tightly the core, even though the core can enter into core barrel, leading to core falling off. A wire-line drilling tool is designed to solve these two problems for complex formation, and also exploit the advantages of wire-line drilling at best.