水平井随钻电磁波测井实时正反演方法  

Real-time forward modeling and inversion of logging-while-drilling electromagnetic measurements in horizontal wells

作　　者：王磊[1,2,3] 刘英明 王才志[4] 范宜仁[1,2,3] 巫振观[1,2,3] WANG Lei;LIU Yingming;WANG Caizhi;FAN Yiren;WU Zhenguan(School of Geosciences,China University of Petroleum,Qingdao 266580,China;Laboratory for Marine Mineral Resources,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266071,China;CNPC Key Laboratory for Well Logging,China University of Petroleum,Qingdao 266580,China;Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]海洋国家实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266071 [3]中国石油大学CNPC测井重点实验室,山东青岛266580 [4]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2021年第1期139-147,共9页Petroleum Exploration and Development

基　　金：国家自然科学基金(41904109,41974146);国家科技重大专项“大型油气田及煤层气开发”(2017ZX05019-005);中国博士后基金项目(2018M640663);山东省博士后创新项目(sdbh20180025)。

摘　　要：基于层状地层随钻电磁波测井伪解析公式,提出边界最优匹配技术,来实现对钻遇地层结构的自适应截断;同时提出散射场一次反射/透射波高阶渐近与扣除方法,极大地提高了索末菲积分的收敛速度,克服了传统数字滤波积分方法精度低、适用性弱等问题,实现了对随钻电磁波测井正演的加速。利用邻井或导眼井等先验信息,通过对地层模型进行交互式调整,为地层界面的预测提供最优反演初值。结合梯度寻优算法形成水平井随钻电磁波测井实时交互式反演方法。实际资料处理结果表明,随钻电磁波测井实时交互式反演方法很好地解决了井周地层边界位置确定的难题,为水平井钻井轨迹最优化和油藏解释提供了依据。Based on the pseudo-analytical equation of electromagnetic log for layered formation,an optimal boundary match method is proposed to adaptively truncate the encountered formation structures.An efficient integral method is put forward to significantly accelerate the convergence of Sommerfeld integral.By asymptotically approximating and subtracting the first reflection/transmission waves from the scattered field,the new Sommerfeld integral method has addressed difficulties encountered by the traditional digital filtering method,such as low computational precision and limited operating range,and realized the acceleration of the computation speed of logging-while-drilling electromagnetic measurements(LWD EM).By making use of the priori information from the offset/pilot wells and interactively adjusting the formation model,the optimum initial guesses of the inversion model is determined in order to predict the nearby formation boundaries.The gradient optimization algorithm is developed and an interactive inversion system for the LWD EM data from the horizontal wells is established.The inverted results of field data demonstrated that the real-time interactive inversion method is capable of providing the accurate boundaries of layers around the wellbore from the LWD EM,and it will benefit the wellbore trajectory optimization and reservoir interpretation.

关 键 词：随钻电磁波测井 水平井 实时正演 交互式反演 地层界面 

分 类 号：P631.8[天文地球—地质矿产勘探]