高分辨率阵列感应井眼校正技术

High-accuracy Processing Technique for Borehole Correction of an Array Induction Tool

高分辨率阵列感应(HDIL)引进的井眼环境校正软件在现场应用中存在着诸多不适应性。建立了高精度仪器响应求解模型及快速计算测井响应信号的方法,将拟合参数区间划分为主要参数区间、次要参数区间、一般参数区间等3部分,并在每一区间内采用基于样条函数的拟线性逼近技术,使测井响应快速计算拟合误差基本在0.5%以下;通过优选建立了等效地层电导率变误差迭代搜索方法,提高了井眼环境校正的精度和稳定性。经地层模型检验以及在大庆长垣东、西部多口探井中的应用,见到了良好的效果。

The existing borehole correction software of an imported array induction tool is found to be of limited applicability in some field applications. This paper presents a method for high-accuracy tool response modeling and the associated algorithm for fast computation of the response signal. The regression parameters are divided into three regions, i.e. primary, secondary, and the rest. Within each region, a quasi-linear spline function is applied such that the regression fitting error of the fast response calculation is in general less than 0. 5%. A technique of variable-error iterative searching solution for equivalent formation conductivity is developed. The accuracy and stability of borehole correction are improved. Good results have been obtained in numerical model tests and in some exploratory wells in the east and west of Changyuan Area of Daqing Oilfield.