CSEM FOR CCS MMV

Value proposition

Marine Controlled Source Electromagnetics (CSEM) is a geophysical technique used to non-invasively measure subsurface resistivity distribution. The resistivity information can be related to subsurface fluid distribution. A risk management tool, CSEM has been used commercially primarily for hydrocarbon E&P. Utilised together with seismic and other geophysical data, CSEM helps to significantly increase the likelihood of finding commercial volumes of hydrocarbons. The technology is also well-suited for CO2 reservoir characterisation, monitoring plume movement and gas saturation levels as well as exploration for marine minerals.

Under appropriate conditions CSEM will provide sensitivity to CO2 saturation and changes. CSEM measures water saturation through measuring resistivity. Exploration of subsurface high-resistivity structures makes it possible to monitor reservoirs for pore-fluid changes with expansion of CO2 plumes affecting CSEM responses. EM is complementary to seismic with high sensitivity in the mid-to-high saturation range (seismic sees main sensitivity in low saturation range). CSEM capabilities for CO2 imaging have been demonstrated both in feasibility studies and a pilot technology survey over Sleipner.

In order to reassure the public about early mitigation of any potential leakage and environmental effects of storing CO2 in geological formations, quantitative measurements are required for characterisation, containment, and conformance monitoring. A multiphysics approach with combination of geophysical parameters will reduce uncertainty. Resistivity data is considered a requirement for quantitative estimation of CO2 saturation. Inversion results for transverse resistance can provide estimates for CO2 volume in place.

MULTIPHYSICS ACQUISITION
Allton has developed a ground-breaking Multiphysics Acquisition Platform (MAP) with specialised equipment for the joint acquisition of both EM and OBN seismic. Our EM node has been designed with the capacity to host a seismic node without additional modification. It can be combined with the Drop & Pop vehicle for denser seismic sampling. The equipment size and modular containerised solution have been designed for installation on vessels of opportunity such as standard Platform Supply Vessels. EM data is processed using our Software Suite with the latest Gauss-Newton 3D inversion.

Identified as a Lower Emissions Oil and Gas Solution (LEOG). Use company contact for detailed value proposition.