Full text loading...
-
Joint Waveform Inversion with the Separated Upgoing and Downgoing Wavefield of VSP Data
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 81st EAGE Conference and Exhibition 2019, Jun 2019, Volume 2019, p.1 - 5
Abstract
Waveform inversion of Vertical Seismic Profiling (VSP) data, including upgoing and downgoing wavefield, is a mature technique for building a velocity model. During the inversion process, upgoing and downoing wavefield have different contribution for the objective function due to energy imbalance between them, which causes the upgoing wavefield cannot be used effectively. In this paper, we propose a method of joint waveform inversion with the separated upgoing and downgoing wavefield of VSP data based on the establishment of multi-objective function. Separating step overcomes the energy imbalance problem for the upgoing and downgoing wavefield, and the direct simulation of upgoing and downgoing wavefield by using the reflectivity method during the inversion simplifies the complexity of separating wavefield. Specially, the zero-offset VSP data can be obtained in τ-p domain to reduce computation cost greatly. Multi-objective optimization method is made use of to solve the problem of joint waveform inversion and the objective function of the joint inversion is also presented in the article. Numerical tests show that our method has the good anti-noise performance as while as getting better inversion results.