Permian Basin - SACROC/Claytonville Pilot
Southwest
Regional Partnership on Carbon Sequestration — Deployment Phase
Background
As part of a comprehensive effort to assess options
for sustainable energy systems, the U.S. Department of Energy has selected
seven Regional Partnerships, through its Regional Carbon Sequestration
Partnership (RCSP) Program, to determine the best approaches for capturing and
permanently storing carbon dioxide (CO2), a greenhouse gas which can
contribute to global climate change. The RCSPs are made up of state agencies, universities,
private companies, national laboratories, and nonprofit organizations that form
the core of a nationwide network helping to establish the most suitable
technologies, regulations, and infrastructure needs for carbon sequestration.
Altogether, the Partnerships include more than 350 organizations, spanning 41
states, two Indian nations, and four Canadian provinces.
The Regional Partnership initiative is being
implemented in three phases. The Characterization Phase began in September 2003
with the seven Partnerships working to develop the necessary framework to
validate and potentially deploy carbon sequestration technologies. In June
2005, work transitioned to the Validation Phase, a four-year effort focused on
validating promising CO2 sequestration opportunities through a
series of field tests in the seven regions. Presently, activities in the
Deployment Phase (2008-2017) are proceeding as an extension of the work
completed to date and will demonstrate that CO2 capture,
transportation, injection, and storage can be achieved safely, permanently, and
economically at a large scale. These tests will promote understanding of
injectivity, capacity, and storability of CO2 in the various
geologic formations identified by the Partnerships. Results and assessments
from these efforts will assist commercialization efforts for future
sequestration projects in North America.
The Southwest Regional Partnership on Carbon Sequestration (SWP)
includes the
states of Arizona, Colorado, Kansas, New Mexico, Oklahoma, Texas, Utah, and
Wyoming. The SWP includes over 50 organizations. The eight states in the
Southwest Regional Partnership account for about 10 percent of U.S. CO2
emissions from stationary sources. The region offers significant potential for
sequestration in saline formations, unmineable coal seams, and depleting oil
and gas reservoirs. Of particular interest is the use of CO2 for
enhanced oil recovery (EOR) in tandem with sequestration.
Project Description
Project Summary
SWP will accomplish a major sequestration deployment and enhanced oil recovery (EOR) in the Permina Basin near Snyder, Texas. This test will follow an injection schedule over 3 - 5 years, leading up to 300,000 tonnes (330,700 million U.S. tons) of CO2 per year. The target formations for this deployment are the hydrocarbon producing Cisco and Canyon formations. Pennsylvanian-age formations such as these are also targets of potential commercial sequestration throughout the western United States. Given the historical success of EOR in this and other southern U.S. basins, our primary research objective of the EOR-sequestration test is to evaluate and maximize efficacy of CO2 subsurface monitoring technologies, and to improve our ability to track the fate of injected CO2 and to calculate ultimate storage capacity.
Injection Site Description
The SACROC EOR-sequestration injection site is located near Snyder, Texas in the Permina Basin. The SACROC Unit in the Texas Permian Basin is the oldest CO2-EOR operation in the United States.
The SACROC oil field unit, the main part of the Kelly-Snyder field, lies along a trend of fields described by Galloway et al. (1983) as the Horseshoe Atoll Play (Figure 1). Hydrocarbons are produced from Pennsylvanian-age strata, including the Cisco and Canyon formations, which represent an isolated platform depositional environment (Figure 2). The Cisco and Canyon formations are carbonates that vary in observed facies, including interbedded pellet, crinoid, algal, and intraclast grainstones and boundstones.
Description
of Geology
The geology of the injection zone is comparable to a large class of potential brine storage reservoirs. Depth of the flooded zones range from ~6300–7100 ft (1900–2200 m) with average reservoir pressures of ~2600 psig. The Wolfcamp shale is extremely low permeability, but the reservoir units approach 10s of millidarcies with porosity ranging from ~2 to ~15%. The oil residing in the field is of high quality. Some free gas was most likely released into the reservoir during initial production, as inferred by increasing producing gas-oil ratios. Pore types include vugs, interparticle, intercrystalline, and fractures. Because the relationship between porosity and permeability is dependent on the pore type, it can be quite variable. Although storage and flow capacity is low, the reservoir has been interpreted to be in fairly good vertical and horizontal communication, based on the consistency of bottom-hole pressure measurements.
In sum, the target reservoir physical properties and character of its oil make the Pennsylvanian carbonates (Figure 2) a good candidate for CO2 enhanced oil recovery as well as concomitant storage of CO2. Good injectivity is also observed by the field operator, and elucidation of potential injectivity reduction following CO2 injection is among SWP goals.
Source
of CO2
Injection at SACROC is ongoing, as it has been for over 30 years. KinderMorgan has a well-developed CO2 handling infrastructure, with about 1850 wells within the 50,000 acre site. KinderMorgan generously agreed to provide all CO2 for the EOR/sequestration analysis at SACROC and Claytonville. The CO2 at SACROC is sourced from the McElmo Dome.
Simulation and Monitoring of CO2
The
project will require extensive monitoring and simulation to determine if the
storage operations are effective in trapping the injected CO2 for
millennia. Vertical seismic
profiling and microgravity methods will be particularly utilized, given their
proven ability to resolve the size of the CO2 plume. Monitoring, mitigation, and
verification (MMV) techniques that will be used include repeat 3-D seismic
surveys, pressure monitoring, groundwater chemistry monitoring, pressure and
fluid sample monitoring from other locations, soil gas sampling, and other
methods. A variety of “in house”
and commercial/public simulation tools will be used, including GEM, TOUGH2,
TOUGHREACT, FEHM, CO2-PENS, COMSOL, THRUST3D, MRKEOS and SWEOS.
Goals and Objectives
SWP’s overall goal is to
validate the information and technology developed under the Characterization
and Validation Phases relative to research and field activities, public
outreach efforts, and regional characterization. Specific objectives include:
·
Develop an overall
methodology that optimizes engineering and planning for future commercial-scale
sequestration projects
·
Conduct successful
large-scale CO2 injection projects targeted at Jurassic and older
sandstone formations
·
Achieve a more thorough
understanding of the science, technology, regulatory framework, risk factors,
and public opinion issues associated with large-scale injection operations
·
Validate MMV activities,
modeling, and equipment operations.
·
Refine capacity
estimates of the target formation using results of the tests
Benefits
to the Region
The SACROC pilot will be an initial high resolution analysis of the potential for CO2 storage in the broader carbonate "Horseshoe Atoll" system, a huge (area and volume) system with potentially enormous CO2 capacity. Given that most of the western side of the atoll is below the oil-water contact, it is particularly appealing ofr large-scale sequestration, as suggested by our Phase I analysis of the region. The SACROC field is also representative of many oil/gas fields throughout the southwestern U.S., and results will be applicable to many such fields. Typically, EOR with CO2 is carried out with an objective to maximize re-production and recycling of CO2 for further EOR. Among the SWP goals is to maximize sequestration, or leaving CO2 in the ground rather than recycling, while not compromosing the efficacy of EOR.