常规电测井联合反演研究与实际应用

Joint Inversion Study of Conventional Electrical Logging and Its Applications

同时利用常规双侧向和双感应测井资料进行电阻率反演求解属于典型的联合反演范畴。常规情况下 1口井中同时进行双侧向和双感应测井不多见 ,但在中国西部某油田部分地区的井中同时有双侧向和双感应测井资料 ,满足电测井联合反演的基本要求。在旋转轴对称地层模型条件下 ,针对常规的双侧向和双感应测井仪器 ,正演分别采用有限元素法 (FEM )和数值模式匹配法 (NMM) ,采取联合反演方式 ,共用修正的Marquardt法作为快速反演方法 ,对地层电阻率、侵入半径和侵入带电阻率等 3参数进行反演计算。从模型和油田实际资料处理看 ,效果较为理想 ,表明了这种联合反演方式有一定实用效果。在此基础上给出了有关反演问题的讨论。

The combination inversion of dual induction and dual laterolog is one joint inversion method. The dual induction and dual laterolog are rarely applied in one well, but in one China oil field, two kinds of electrical logging data are simultaneously presented in the same well, which can meet the need of joint inversion. In this paper, forward modeling methods such as FEM(Finite Element Mehtod) and NMM (Numerical Mode Matching method), and inversion method --the modified Marquarde method are employed to compute the virgin resistivity, the flushed zone resistivity and invasion radius jointly. The application results in the China western oilfield have shown that the joint inversion is much more reliable and effective than the single-method inversion. On the basis of the applications, some discussions about resistivity inversion are given.