In this First Break article from June 2024, TGS experts Julien Oukili, Nick Lee, Martin Widmaier, Omar Baramony, Roberto Ruiz and Eric Mueller discuss the value of recent technological advances in seismic acquisition and processing for CCS site-screening projects, using multiple case studies from offshore north-west Europe.
Introduction
In many ways, subsurface projects for offshore carbon storage follow the same principles and geophysical methods that have been employed for decades in the oil and gas industry (O&G). One example of this is the adoption of seismic time-lapse technology to monitor changes in fluid saturation and migration in the subsurface, a technology that has been adopted in both oil field reservoir management and carbon storage monitoring. However, the search for more suitable storage sites does present new challenges and opportunities to the subsurface community, whether that be searching for sites that consider different storage and trapping mechanisms without the need for discrete trap geometries (so-called migration assisted storage) or re-examining areas with no expected access to petroleum charge in underexplored, data-lean areas.
In recent years, north-west Europe there has been more co-located petroleum and CCS (carbon capture and storage) activities, with increased near-field O&G exploration co-existing alongside CCS site evaluation. Northern Lights is probably the best-known example of this, with its close geographical association with the giant Troll field (Furre et al., 2019). The increasing pressure to develop oil and gas reserves has resulted in significant advancements in seismic acquisition and processing technology. This progress has been particularly instrumental in supporting exploration efforts in mature basins, where enhancing the quality of seismic information has been crucial. These advances have spurred the emergence of a growing number of CCS projects.
Figure 1 - Incoherence attribute extraction at the top of the Bunter sandstone horizon, from the legacy KPSTM full stack (left) versus the reprocessing results (right) over the Endurance area. The strong incoherence response (orange to white) on the legacy KPSTM is not necessarily consistent with geological events and adds uncertainty to the interpretation of faults and fractures. The phase reversal is better outlined on the latest SNS dataset, as well as the fault system towards the north (arrows).
Read the full article here.