基于模型的地震波阻抗反演在水平井随钻跟踪中的应用

在水平井地质导向随钻跟踪中,通常利用临井的测井资料建立地质导向前导模型指导随钻。该模型在水平井着陆阶段能相对准确地预测目的层的深度,但在水平段随钻跟踪时,要保证钻头始终控制在目的层内物性较好的部位钻进,仅靠临井的井资料插值预测储层物性,误差就比较大。为此,针对地质导向前导模型储层横向非均质预测的缺陷,把基于模型的地震波阻抗反演技术引入到地质导向模型修正中,预测目的层横向非均质性,指导水平井水平段随钻跟踪服务,以控制井轨迹始终在储层物性较好的部位钻进,提高储层钻遏率。此方法经过实钻水平井的验证,达到了良好的效果。

Application of Seismic Inversing Method Based on Model to the Geosteering of Horizontal Well while Drilling

During horizon well geosteering, the adjacent well logging data are often used to build the geosteering model in order to guide well drilling. With this model, the depth of target zones can be predicated in the landing process of horizon well. However, the inaccuracy is large if only the adjacent well data is used to forecast the reservoir physical property by interpolation method during horizon well geosteering. Therefore, the seismic inversing method based on model is introduced into geosteering model to predict the reservoir lateral anisotropy. By this method, the drawback of lateral reservoir anisotropy forecast with geosteering model can be over-come, and the well path can be controlled in the reservoirs with good physical properties. Therefore, the reservoir encountering ratio can be increased greatly. It has been confirmed that this method is effective through application to horizon well drilling.