On the long list of barriers to the accelerated development of carbon storage put together by the US Department of Energy (DOE) is the need for a widely accepted method for evaluating and managing underground storage sites.
At the recent CO2 Conference in Midland, Texas, John Litynski, DOE’s director of carbon transport and storage, said they are interested in testing the CO2Storage Resources Management System (SRMS) developed by the CO2 Storage Resources Committee, a committee of the SPE Carbon Dioxide Capture, Utilization, and Storage Technical Section.
A slide from the presentation by Litynski said “The SPE system offers a common terminology for the many people involved with developments, allowing them to communicate about the complicated subsurface reality of storage.”
The SRMS, which was initially rolled out in 2017, is competing for acceptance with other proposed systems for evaluating, planning, and classifying storage systems.
Its origin runs parallel to SPE’s Petroleum Resources Management System (PRMS), which is widely used to evaluate oil reserves globally.
In both cases, the system was developed with a goal of creating a widely used method at a time when there were multiple options vying for acceptance.
Both SPE systems offer various estimates of reservoir capacity, classed by the level of uncertainty associated with future development of that level of capacity.
In an oil field, the highest-probability class is Proven reserves, which are the volumes of oil and gas most likely to be produced due to economic and technical criteria.
For CO2 storage, the highest class is Capacity, followed by Contingent Storage Resources, and Prospective Storage Resources. The lowest level is Inaccessible Storage Resources.
At this point it is being used at a time when there are a limited number of storage sites, so gas sequestration site performance data are limited
Litynski described a multiyear project where they want to evaluate how accurately pre-construction estimates based on SRMS compare to the operating performance after a site opens.
He sees this test as an opportunity to evaluate and identify the improvements needed to scale up the storage business—which DOE hopes will rapidly expand.
Adjustments are expected in the evaluation system as more data are gathered and the storage industry matures. The SPE SRMS document states that the subcommittee that created the system expects to change the tool as the storage methods and business evolve.
One likely driver of change is the increasing scale of storage operations. Litynski described an industry where multiple storage sites, and possibly oil fields using the gas for enhanced recovery, will be linked into hubs to handle massive inflows of captured gas. These complex systems will be in places where they interact with other operations, ranging from producing oil and gas fields to wastewater injection sites.
“We have a lot of great models for project scale—we need to extend that to a basin scale,” Litynski said.
