The DigiMon concept involves the combination of low cost, low fidelity distributed measurements covering large areas, and high-fidelity measurements covering smaller areas. Conventional cross-well seismic tomography falls into the latter category, and could provide a good deal of value to DigiMon in this role. The need for wireline operations indicate that conventional cross well tomography is most suited to land-based and survey oriented CO2 storage applications. Two potential approaches for adapting cross-well seismic tomography in order to make it more suitable for subsea and continuous monitoring CO2 storage applications include (i) Using ambient noise as the source (No wireline operations for the source) and (ii) Using fibre optics as the receiver (No wireline operations for the receiver).
The report gives a basic concept description of cross-well seismic seismic technology, both with active seismics and ambient noise, and their application with distributed fiber optics sensing. The report also describes the infrastructure for carrying out cross well/fibre optic measurements at Svelvik, and a proposal for a measurement campaign to be carried out as part of the DigiMon project.