水平井随钻伽马测井快速反演储层界面

Fast Inversion of Reservoir Boundary Using Gamma-Ray Logging-While-Drilling in Horizontal Well

随钻伽马测井地质导向是提高水平井储层有效钻遇率的重要方法，但目前研究随钻伽马测井的方法计算速度有限。为实现实时地质导向，基于水平井地层中随钻伽马测井探测范围的空间特征，确立了随钻自然伽马测井的正演方法；利用该正演方法，建立了在不同地层中离边界不同距离情况下的随钻自然伽马测井响应图版；再利用该图版，建立普遍适用的随钻伽马测井快速反演储层界面的方法。在双层介质模型和随钻实例地层中，可以快速、准确地反演出地层界面的位置，表明该方法可用于随钻伽马测井的实时地质导向工作。

Geosteering by using Gamma-ray logging-while-drilling was an important method to improve the effective drilling rate of reservoir in horizontal wells, but the calculation speed of the method for studying the gamma-ray logging was limited. In order to realize real-time geosteering, based on the detection spatial characteristics of LWD gamma-ray logging tool in horizontal wells, the forward method of LWD gamma-ray logging was established. Using the forward method, the logging responses chart of LWD gamma-ray logging with different distance to boundary in different strata was established. Finally, the fast inversion method of reservoir boundary of LWD gamma-ray log- ging in common use was established. In the double layer medium model and LWD strata example, the inversion method can be used to obtain the boundary position quickly and accurately. This indicates that the method can be applied to the real-time geosteering of LWD gamma-ray logging.