The marine Controlled-Source Electromagnetic (CSEM) method has become a well-established geophysical tool for 3D imaging of multiple resistive bodies. While traditionally being considered an exploration tool, improved data quality and advanced processing methods put mapping detailed resistivity distributions using CSEM methods in reach. Particularly in conjunction with 3D-and 4D-seismic technology defining the structural container, marine CSEM can add a complementary image of the bulk distribution of resistors. Using real data and supported by modeling, we assess the capability of CSEM technology for time-lapse monitoring, including the dominant sources of non-repeatability.
The marine controlled-source electromagnetic (CSEM) method is an important tool for offshore exploration. It allows recovery of subsurface resistivity, a key hydrocarbon (HC) indicator, using modeling- and inversion-based interpretation of the EM data acquired on the seafloor. Application of CSEM can reduce risk and optimize drilling operations, as well as improve estimates of HC reserves. The CSEM workflow consists of the following main steps: feasibility study, survey design, data acquisition, processing, and interpretation. Feasibility study and data interpretation rely heavily on 3D EM modeling to properly select and plan surveys and recover the 3D subsurface resistivity image. Detection of deep small targets immersed in anisotropic environments is a challenging task for the current CSEM technology, making it essential to employ the best practices in performing reliable feasibility studies. To manage this task, a skilled modeler needs to take into account all available geological and geophysical data to build a 3D Earth model and utilize accurate 3D EM modeling software. The fast and reliable 3D EM modeling that can accurately handle arbitrary anisotropic resistive media with complex structural interfaces and HC reservoirs would make a crucial contribution to the success of CSEM technology.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.