CSEM Inversion in CMP Domain Using Analytical Derivatives

Abstract

The employment of marine controlled-source electromagnetic method (mCSEM) to reduce risks in the exploration of oil and gas has being gradually growing; however the interpretation of the rendered data is still a challenge for the oil industry. Methodologies for generating geological profiles or maps are often unsatisfactory as well as purely 1D inversion. On the other hand, the algorithms of 2D and 3D inversion require complex implementation and high computational costs. This work presents the needed parts to implement a work-flow of mCSEM inversion, that inverts the data in common mid point (CMP) domain as a set of 1D models, which correspond to their respective CMP cells. Including the analytical derivatives of the responses for 1D models with respect to the resistivities. These techniques allows to recover a section, corresponding to an mCSEM line, in few minutes, which in association with seismic data, can provide very useful results for exploratory works.