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利用有限元方法建立了包含井眼、侵入带、上下围岩和目的层的横向测井电阻率响应数值计算模型，利用阻尼最小二乘法建立了相应的快捷、有效的反演算法，根据横向测井的电阻率响应同时反演地层电阻率、侵入带电阻率和侵入带半径。该算法对于３个或４个梯度电极系（或电位电极系）的测井结果均适用。讨论了模型算法对初值的依赖性，当初值在较大范围内变化时，反演结果均能在真值或真值附近收敛。
The numerical calculation model of transverse well resistivity response including wellbore, invaded zone, upper and lower surrounding rock and target layer is established by using finite element method. A corresponding fast and effective inversion algorithm is established by using damped least squares method. According to the transverse measurement The well’s resistivity response simultaneously inverts the formation resistivity, intrusion zone resistivity and invaded zone radius. This algorithm is suitable for logging results of 3 or 4 gradient electrode systems (or potential electrode systems). The dependency of the model algorithm on the initial value is discussed. When the original value changes in a large range, the inversion results can converge around the true value or the true value.