基于比能理论的钻头工作状态监测方法

钻头工作状态是影响钻井机械钻速和钻井效率的重要因素之一,而钻头的地下工作环境具有高隐蔽性和不确定性,一旦出现异常,很难在第一时间被现场施工人员发现.文中分析了钻头工作状态的影响因素,利用Farrelly等人提出的比能法,通过多元线性回归模型计算钻头扭矩,得到钻进过程中钻头比能值监测的工程简化模型.比能监测值的异常变化,...

Monitoring method of drilling bit working status with mechanical speck energy theory

The working state of drilling bit is one of important factors of affecting the ROP and drilling efficiency.However,the down hole environment of bit is of high concealment and uncertainty.When abnormal bit condition occurs,it is hard for operators to identify it in time.In this paper,the factors of affecting the working status of drilling bit are analyzed.Based on the mechanical specific energy theory proposed by Farrelly et al.,a simplified mechanical specific energy monitoring model of bit during drilling penetration is obtained through the calculation of drilling bit torque with a multiple linear regression model.Abnormal working state of drilling bit can be reflected according to the abnormal change of mechanical specific energy monitoring value.This paper analyzes the change trend of mechanical specific energy value under the conditions of bit balling,vibration,bottom hole balling,bit dulling in order to detect the drilling bit abnormality of bottom hole rapidly.A well in Karamay Oilfield is used to test the rationality and validity of the model,the result shows that the model is helpful for the improvement of ROP and decrease of drilling cost.