Carbon Storage Atlas
- Scale-Up to Phase II
- Regional Accomplishments
- Story of Interest
- Research vs. Commercial
Scale-Up to Phase II
The Southwest Regional Partnership on Carbon Sequestration (SWP) Phase I project, by definition, was a study in the theoretical availability of carbon dioxide (CO2) emissions and CO2 storage capacity of the Southwestern United States. An analysis was conducted for the broad region, with the development of a plan for the implementation of capture, transport, and storage/utilization of CO2, with existing CO2 pipelines from natural sources in Wyoming, Colorado, and New Mexico as the backbone. The results of that analysis identified specific areas in the region with unique but ubiquitous geological characteristics that could be utilized as sounding boards (pilots) for larger-scale (commercial) CO2 capture and storage sites. The most significant storage/utilization option identified within the region, along the CO2 transport backbone, was CO2-enhanced oil recovery (EOR), with the Permian Basin of Texas (Scurry Area Canyon Reef Operator’s Committee [SACROC] Unit) being the largest. In Utah, also adjacent to the CO2 transport backbone, the Paradox Basin (Aneth Field) was a smaller EOR prospect, with geology distinct from the Permian Basin, but more representative of reservoirs within the Colorado Plateau. Enhanced coalbed methane (ECBM) production utilizing CO2 was attempted as another method of storage within the region. Each of the three pilot projects were able to gather and analyze significant data that expanded on the Phase I dataset.
The most significant regional-scale accomplishment in the Southwest Regional Partnership on Carbon Sequestration (SWP) region was the initial development of the regional Carbon Storage Atlas, as part of the National Energy Technology Laboratory’s (NETL) National Carbon Sequestration Database and Geographic Information System (NATCARB) effort. This task focused on the major sedimentary basins within the region, identifying significant geologic reservoirs that were sufficiently deep, porous, and permeable, and were capped by impermeable units that would prevent upward migration of injected carbon dioxide (CO2). Areal and thickness (volume) extents of each significant candidate formation were mapped and combined with porosity values to develop a theoretical CO2 capacity estimate for reservoirs, basins, individual states, and the entire region. At least 15 large sedimentary basins reside in the Southwest United States, with each basin containing several potential CO2 reservoirs (saline, oil, gas, coal). The cumulative storage capacity of all reservoirs, in all basins within the SWP region, is conservatively estimated at more than 100 billion metric tons of CO2. This storage capacity is sufficient for 100% capture from all coal- and gas-fired power plants in the region for the next 100 years (at current emission rates).
Story of Interest
The largest Southwest Regional Partnership on Carbon Sequestration (SWP) Phase II field site was in the Scurry Area Canyon Reef Operator’s Committee (SACROC) Unit of the Permian Basin, Texas. The SACROC Unit is the oldest actively injecting carbon dioxide (CO2) project in the United States, utilizing CO2 since 1972. The SWP data collection and analysis of the ongoing CO2-enhanced oil recovery (EOR) at the SACROC Unit was comprehensive, gathering extensive surface and subsurface geologic, geochemical, and geophysical datasets. These datasets, in turn, fed simulations that evaluated the long-term effects of CO2 injection, migration, caprock integrity, and trapping mechanisms. One of the conclusions of the simulation activities at the SACROC Unit is the concept of CO2 injection into deep saline aquifers immediately below an oil reservoir. Carbon dioxide injected below an oil reservoir will mix with the saline water and form a plume that rises due to buoyancy. When the buoyant plume encounters an oil reservoir, simulations indicate most of the CO2 will dissolve into oil. Although some CO2 will remain free, it does not tend to migrate vertically because oil density is similar to CO2 density, causing less buoyancy-driven vertical migration. The free CO2 behaves more like residual CO2. Although free CO2 may reach the top of the target formation, an oil reservoir is always covered by a caprock. Therefore, CO2 cannot easily escape. Although an oil reservoir provides several advantages for minimizing the potential vertical migration of CO2, its size and volume are limited for CO2 storage. In comparison, the potential for CO2 storage in brine formations is immense.
Research vs. Commercial
The Southwest Regional Partnership on Carbon Sequestration (SWP) Phase II pilot studies were each conducted at existing oil- and gas-producing sites, with the industrial partners and operators having a financial interest in energy extraction rather than carbon dioxide (CO2) storage. Carbon dioxide was a necessary component of the enhanced oil and gas extraction at each pilot site, with the field operators viewing CO2 as a valuable resource, much like any fuel. To this end, the operators at each field site tailored CO2 injection, often combined with water injection (and subsequent co-production and recycling), varied over time and field site, to maximize oil and gas recovery rather than storage. SWP research activities at the Phase II sites, from monitoring, verification, and accounting (MVA) to risk assessment to simulation, had to consider this more complex intermittent injection and constant production when attempting to understand the entire system (reservoir).
Conversely, commercial-scale sites would likely be tailored to maximize CO2 storage, including nearly constant and consistent injection at dedicated injection wells, with dedicated monitoring wells and other monitoring infrastructure. While attempting to forecast long-term effects of CO2 at a commercial site is not trivial, the steady-state injection activity reduces much of the complexity of an enhanced oil recovery (EOR) or enhanced coalbed methane (ECBM) site.
- Advanced Resources Inc (ARI)
- Baker Hughes
- Interstate Oil and Gas Compact Commission
- Kinder Morgan
- Los Alamos National Laboratories
- Navajo Nation Oil and Gas Company
- New Mexico Institute of Mining and Technology*
- Resolute Natural Resources
- Sandia National Laboratories
- Texas Bureau of Economic Geology
- U.S. Bureau of Land Management
- U.S. Department of Agriculture
- University of Oklahoma
- University of Utah
- Utah AGRC
- Utah Geological Survey
* Lead Organization