Studies on Rock mechanical characteristics testing and drill Bits rock-breaking efficiency in deep wells
Taking the rock core sample on-site,using the triaxial stress test device to simulate the testing of rock mechanics parameters in the original formation environment,the mechanics characters can be obtained.Based on the H-J-C rock failure criteria,a 3D non-linear contact dynamic model of dynamic rock breaking is established using finite element method,in which anisotropy,strata dip and friction factor of drilling bit and rock are considered.The relationship between drill pressure,torque,speed and rock-breaking efficiency are also studied.The results indicate that the depth of broken rock depends on the impact and have nothing to do with the rotation; when the WOB did not meet the crushing pressure of the rock volume,the torque changed a little; but when the WOB exceeded the crushing pressure,the torque changed a lot; at the same time,the drill speed mainly had no effect on the drill torque.The drill bit is the main rock-breaking tool which is used in the deep strata of petroleum well drill progress and its rock-breaking efficiency is the important evidence to evaluate the bit’s performance and improve the design quality.In this paper,the geometric nonlinear characteristics of drill bit is considered,the stress and strain of the drill bit are obtained,which provided a new method to better analyze and evaluate the rock-breaking efficiency of bit and enhanced the scientific nature and reliability of the rock design quality.
rock core test rock breaking mechanism drilling parameters rock-breaking efficiency
YANG Shangyu YAN Yifei XU Zhiqian YANG Xiujuan
College of Pipeline and Civil Engineering China University of Petroleum Qingdao 266580,Shandong,China
国际会议
西安
英文
1-5
2012-10-01（万方平台首次上网日期，不代表论文的发表时间）