重构电阻率曲线识别水淹层的方法及应用

Method and Application for Identifying Waterflooded Layer with Reconstructed Resistivity Curves

测井解释评价水淹层时,由于原生地层水与注入水混合后性质多变,混合地层水电阻率变化没有普遍规律可循。利用神经网络能够准确模拟输入与输出之间复杂非线性关系的特点。重构油层水淹前的电阻率,利用重构电阻率曲线与实测电阻率的差异,表征注入水对电阻率曲线的影响。根据注入水性质,利用水淹前、后电阻率的变化量定性表征流体性质的变化,利用水淹指数对水淹层进行分级评价,能够准确识别水淹层,在实际生产中应用效果好。

In interpreting and evaluating waterflooded layer,there is no general rule for the variation of the mixed formation water resistivity,since the original formation water is mixed with injected water.Resistivity curves are the most important curves for identifying oil and water.However,it does not really reflect oiliness because of the influence of mixed formation water resistivity and total water saturation.Under the influence of injected water with different properties,the same oil layer may be characterized by high resistivity or low resistivity,which makes the interpretation of waterflooded layer difficult.Because the neural network can accurately simulate the complex nonlinear relationship between input and output,it can reconstruct the resistivity of the non-waterflooded oil layer. The difference between the reconstructed resistivity curve and the measured resistivity is used to characterize the influence of injected water on the resistivity curves.According to the nature of injected water,the resistivity change of non-waterflooded oil layer and waterflooded oil layer is used to characterize the change of fluid properties.The index of waterflooded is used to evaluate it,so the waterflooded layer can be accurately identified.In actual production,the application effect is good.