斜井井间反射波逆时偏移成像技术及应用效果初探

Reverse-Time Migration Imaging for Cross-Deviated Well Seismic Reflected Wave and Its Application

为解决油田开发过程中地面地震资料无法解决的高分辨率精细储层和隔夹层描述等问题,同时满足实际油田开发过程中既有直井又有斜井的井间地震资料成像需要,探讨了井间地震交错网格有限差分逆时偏移算法以及吸收边界等问题,针对共面斜井井间地震的理论模型和实际地震资料进行了逆时偏移成像。结果表明,偏移算法实现正确,实际资料逆时偏移成像剖面的信噪比和分辨率远高于地面地震成像剖面,且层间细节变化更丰富,与实际地层变化特征吻合较好,结果可信,为解决油田开发过程中地面地震资料无法解决的高分辨率精细储层和隔夹层描述等问题奠定了基础。

Both vertical well seismic imaging and deviated well seismic imaging are needed in oilfield development. At the same time, it is not possible for us to obtain detailed reservoirs and interlayers with high resolution when only surface seismic data are used. In this research, we investigated cross well staggeredgrid finite-difference reverse-time migration algorithm and absorbing boundary conditions. In the end, we obtained reverse-time migration image from the theory model and field seismic data. The result shows that the migration algorithm is correct, and the signal-to-noise ratio and resolution ratio of reverse-time migration imaging profile are higher than that of surface seismic imaging profile. What is more, for the reversetime imaging profile; the details of layers are clearer, and it coincides well with the actual strata, which makes it much more credibl＇e. This means we can use the above method to get detailed reservoirs and interlayers with high resolution.