冲击回转碎岩机理研究

Study on rock fragmentation mechanism of percussive rotary drilling

孙琦 杨甘生

中国地质大学（北京）深部地质钻探技术国土资源部重点实验室，北京 100083

Key Laboratory of Ministry of Land and Resources for Deep Geological Drilling Techniques, China University of Geosciences, Beijing 100083

地下岩体中，天然地存在有许多微观裂纹与节理。在钻头的冲击回转合作用中，冲击使近钻头的岩石发生裂纹断裂、破碎，形成破碎小坑；使远离钻头的岩石中的微观裂纹扩展、连通、甚至断裂；在离钻头更远区域，使岩石产生新的微观裂纹。回转使冲击产生的破碎小坑沿圆周方向扩大；并使钻头上的金刚石颗粒换位。在回转冲击的联合作用下，岩石中的裂纹不断产生、扩展、断裂，从而达到高速碎岩的目的。本文简单回顾了冲击破碎岩石理论的发展，并着重从与冲击回转钻井技术密切相关的角度从数量关系上介绍了裂纹的萌生和扩展。更分别介绍了冲击作用和回转作用分别对岩石中裂纹的萌生与扩展的影响。

There are a lot of microfissures and joints natively in subsurface rock matrix. During percussive rotary drilling of drilling bit, shock makes the rock of near-drilling bit generate crack fracture and breakage, forming broken craterkins, which makes the microdissures expand, connect and even fracture in the rocks far from drilling bit. New microdissures are formed in the further area from drilling bit. Rotary drilling makes the shock-generated craterkins to expand along peripheral direction, which changes the positions of diamond particles on bit. The cracks in rock continuously generate, expand and fracture under the percussive rotary action, which reaches the destination of high-speed rock fragmentation. This essay briefly introduces the development of percussive rock fragmentation theory. The generation and development of crack are introduced according to the angle of related to percussive rotary drilling from quantitative relation. The paper introduces the effect of percussive action and rotary action on the generation and expansion of crack in rock.

10.6056/dkyqt2012z1026