碳酸盐岩地层水平井电阻率各向异性校正方法研究及应用

The Method and Application of Horizontal Well Resistivity Anisotropy Correction in Carbonate Formation

在测井资料储层评价中,地层电阻率是储层有效性评价和流体性质识别的重要参数。水平井井眼轨迹轴线与地层水平面的相对位置变化,使得水平井中双侧向仪器测量电阻率时发出的电流穿过地层的方式发生变化。由于碳酸盐岩地层上覆压力和侧压不同,使得地层不同方向的电阻率不同。水平井主要测量地层垂直方向上的电阻率,直井主要测量地层水平方向上的电阻率,因此在同一深度下的水平井和直井测量结果不同。根据导眼井(直井)和斜度井(水平井)致密段地层的统计结果,拟合出横向各向同性电阻率校正公式,对塔中地区碳酸盐岩地层水平井电阻率进行各向异性校正,将校正后的电阻率用于储层的流体性质识别并与试油结果对比,取得了良好效果。

In the reservoir evaluation with logging data,the formation resistivity was an important parameter to evaluate the reservoir effectiveness and identify the reservoir fluid properties.Changing in the relative position between the horizontal well trajectory and the formation horizon caused the changes in the current of dual lateral logging tool passing through the formation in the horizontal wells.In carbonate formation,the difference between overburden pressure and lateral pressure induced the variation in resistivity from different directions.In horizontal wells,the dual lateral logging tool was used to mainly measure the vertical resistivity.In vertical wells,the dual lateral logging tool was used to mainly measure the horizontal resistivity.Therefore measurement results are different between horizontal wells and vertical wells in the same depth.According to the statistical results in horizontal wells and vertical wells in the compacted formation,a resistivity anisotropy correction formula is derived for the transversely isotropic resistivity for correcting resistivity anisotropy of horizontal wells in carbonate formation,and corrected resistivity is used for identifying reservoir fluid properties and comparing it with oil test results,good results are achieved.