微柱型聚焦测井仪测井响应模拟及应用

微柱型聚焦测井仪能够提供3条不同探测深度的原始测量曲线R_(B0)、R_(B1)、R_(B2),可以反映冲洗带电阻率、泥饼电阻率以及泥饼厚度。利用有限元方法对三维非均匀介质模型下微柱型聚焦测井仪进行建模分析,将偏微分方程定解问题转换为求取泛函极值问题。通过仿真计算,研究了微柱型聚焦测井仪的探测深度与探测范围,不同泥饼厚度、不同冲洗带与泥饼电阻率对比度下的测井响应。利用最小二乘方法对微柱型聚焦测井仪测量数据进行反演处理,得到冲洗带电阻率、泥饼电阻率以及泥饼厚度,在此基础上合成了微电位、微梯度曲线。实际资料处理证明该理论与方法可应用于测井资料处理,可对薄层以及油水层评价起到重要作用。

Numerical Simulation and Application of Micro-cylindrically Focused Logging Responses

The micro-cylindrically focused logging tool can provide three raw measurement curves RB0, RB1 and RB2.The three resistivity curves are of different investigation depths, and they can reflect the resistivity of flushed zone and mud cake as well as mud cake thickness.The micro-cylindrically focused logging is simulated and analyzed by using finite element method in three-dimensional inhomogeneous model, and the definite solution problems of partial differential equations are converted into calculation of functional extreme problems.The detection depth and detection range of micro-cylindrically focused logging tool is studied, and the logging responses are computed under conditions of different mud cake thicknesses and different contrasts of resistivity between flushed zone and mud cake.The flushed zone resistivity, mud cake resistivity and mud cake thickness were obtained from micro-cylindrically focused logging data by the inversion disposal based on least square method, and by which the micro-normal logging curve and micro-lateral logging curve were synthesized.The actual data processing result has proved that the theory and method in this article could be applied to logging data processing, and it is of great importance to the formation evaluation of thin layer and oil-water layer.