Here is the latest in our blog series on CCS risk and uncertainty. THe link to the whole set is included. The next chapter will be posted tomorrow, Tuesday. Understanding issues that have occurred is a good way to anticipate and mitigate risks in a new project.
In the Tordis Field (Norwegian sector, North Sea) oily water was injected for disposal into a shallow aquifer thought to be the Utsira Sands, a well-known, good-quality reservoir. However, a miscorrelation incorrectly identified the intended storage reservoir. It was not the Utsira, which was later determined to be absent due to a pinch-out. Instead, the water was injected into a sand lens within the overlying Nordland Group (denoted by a star at the Tordis well location in the Figure below). Because this lens had a limited volume, reservoir pressure increased rapidly during injection and the seal was breached resulting in fluid escape and the leakage of oily water upward to the seafloor. This leakage created a crater 30-40 meters across and 7 meters deep on the seabed. In the wake of this, because the Utsira Sands are the CO2 storage reservoir at the Sleipner carbon storage project, environmental organizations began questioning the security of storing CO2 in the Utsira Sands. Not only does this case study illustrate how we can misinterpret the target injection reservoir and its potential impacts, but it also demonstrates how the failure of one project can implicate others. Check out more posts in this series either on our LinkedIn page or on our blog. https://lnkd.in/g5rZr7Xm
Arash Daniali
2mo
This post sheds light on a critical issue in subsurface storage—how misidentifying target reservoirs can have severe environmental impacts. As a CCS reservoir engineer, I see this as a reminder of the importance of accurate reservoir characterization. The possibility of reinterpreting existing seismic data, reviewing old seismic, or conducting new seismic surveys can ensure both old and new interpretations align accurately. In CO2 storage, especially in formations like the Utsira Sands, robust monitoring protocols are crucial to ensure long-term containment. What advancements in reservoir characterization have others found effective in supporting CO2 storage security?
Mark Steuer
2mo
One wonders how well the data were evaluated and whether inexperience played a role.
Very informative
Research Associate Professor at Bureau of Economic Geology, University of Texas at Austin
2moDo you know what their injection pressure was? For CCS, we are limited to 90% of fracture pressure (or less, depending on the permit). It’s far more tightly regulated than SWD and far more carefully planned, both of which make it much harder to create this sort of adverse consequence.