Abstract: In this paper a comprehensive 3-dimensional analysis for rock-bit interaction is made and relevant models, which account for the anisotropic drilling characteristics of both the formationand the bit, are derived. Combined with the BHA analysis,the models are used to realize the prediction of drilling trajectory and to back-calculate the related coefficients from the well history information. Ten groups of coefficients for ten strata and three kinds of bits are obtained by means of back calculation of the actual drilling data of four wells in central Daqing.The drilling trajectory for four sections of two holes, in this area are predicted.The predicted results give an average error for deviation angle is 0.162(°/100m)and an average error for azimuth angle is 0.988(°/100m).

摘要： 本文对钻头与地层相互作用进行了全面的三维分析,在综合考虑钻头各向异性和地层各向异性对井眼轨迹影响的基础上,建立了钻头与地层相互作用的三维钻速模式.利用该模式并结合钻柱力学三维分析,可以预测定向井井眼轨迹,还可以利用定向井井史资料,反求有关系数.通过对大庆油田萨中区四口定向井井史资料的分析,得出该地区10个层段3种常用钻头的10组数据.在此基础上,对该地区两口实验井分四个井段进行了跟踪预测,其结果是,井斜平均误差为0.162°/100m,方位平均误差为0.988°/100m.

关键词: 钻头, 各向异性, 定向钻井, 井眼, 轨迹预测, 三维模型