Multi-parametric full waveform inversion of VSP data considering borehole deviation error

초록

Full waveform inversion (FWI) of vertical seismic profiling (VSP) data provides a promising high-resolution image which can describe structural details. But these images suffer from the positioning errors of receivers that occur during drilling process. This causes a failure of FWI in the deeper parts which are mostly the main targets of oil exploration. To solve this problem, we suggest an algorithm which parameterizes receiver location for FWI of VSP data. By adding receiver coordinates to inversion parameters, we can invert the exact locations of receivers. However, it is difficult to invert both velocity and coordinate parameters simultaneously because it leads to the expansion of model space without increasing data. So, we try to stabilize the inversion problem with a regularization on location parameters. The regularization term is designed to reduce the curvature of borehole trajectory. In the end, we can successfully invert VSP data without accurate information of receiver location. © 2018 Society of Petroleum Engineers. All rights reserved.