Scale-Up to Phase II

The Midwest Geological Sequestration Consortium (MGSC) shifted from Phase I regional characterization to Phase II for specific pilot studies. A five-tier screening process was used to select the candidate sites, based on oil reservoir or coal characteristics, site surface conditions, wellbore conditions, operational and development history, and owner/operator cooperation. After rigorous application of the screening criteria to numerous sites, several trips to the oil fields under consideration, and discussions with oil field operators and owners, three enhanced oil recovery (EOR) sites (a single-well huff n’ puff, an immiscible carbon dioxide [CO2] test, and a miscible [liquid] CO2 test) and one enhanced coalbed methane (ECBM) site (coalbed CO2 injection test) were chosen. MGSC had originally proposed a 10,000-metric-ton deep saline injection project for Phase II, but when Phase II and Phase III merged together, the volume to be stored was increased and the saline project was shifted to Phase III.

In Phase II, MGSC developed and tested the workflow in moving from regional characterization to site-specific characterization. The process was successful because MGSC was able to connect with existing operators in the Illinois Basin interested in demonstrating EOR using trucked-in CO2. During the Phase II projects, the MGSC focus shifted to the operational logistics of CO2 injection and supporting activities, such as contacting road commissioners to find out when you could drive heavy trucks on rural roads, what roads you could drive on, and what seasons you could drive on those roads. An unanticipated lesson learned was the impact of weather on field operations (e.g., that you could not do a field study in the winter because there was a potential problem with the roads, or that seasonal restrictions were placed upon these roads). In addition, MGSC had to be sensitive to agricultural land use and was required not to interfere with farming operations.

Regional Accomplishments

A key conclusion of the Phase I studies was that the geology of the Illinois Basin is favorable for carbon dioxide (CO2) storage. In some localities, two or more potential CO2 sinks are vertically stacked. The primary focus of the Phase II study, however, were the properties of the rock units that control injectivity of CO2, the total storage resources, the safety of injection and storage processes, and the security of the overlying rock units that act as seals for the reservoirs. For Phase II (2005–2011), four small-scale field tests were conducted. They included testing the ability to adsorb gaseous CO2 in a deep, unmineable coal seam, and the ability to store CO2 and enhance oil production in mature oil fields. Each of these field tests had an extensive monitoring program for sampling air, shallow groundwater, and fluids from the injection zone and included geophysical and cased-hole logging and monitoring of pressure changes to understand the fate of injected CO2 at the test sites. The integrity of the entire process was scrutinized in detail to understand what contribution Illinois Basin geological sinks can make to national and international carbon storage goals and what technology developed here can be applied to other regions.

Story of Interest

Near the Phase II Loudon huff n’ puff pilot project, one of the local residents raised questions about odor and taste problems in their home shallow-bored water well. The project team collected and analyzed well water samples from the neighbor and determined that the likely source of the odor/taste problem was related to iron- and sulfate-reducing bacteria unrelated to project activities.

The Phase II landowner interaction helped to establish Phase III groundwater monitoring efforts, which occurred over the pre-operational (background), operational, closure and post-closure periods of the carbon dioxide (CO2) injection project to establish groundwater quality variations and characterize the impact or lack of impact of project activities. Two groups of wells were used to monitor groundwater quality: (1) the “research” wells, installed specifically to monitor project activities and determine the local groundwater flow regime, and (2) the private wells, to monitor quality, fill spatial and depth gaps, and provide an opportunity for public engagement to develop relationships with local well owners.

Residential sampling identified elevated iron and arsenic in a couple of the shallow groundwater wells that had previously been undetected; this voluntary effort provided valuable information to project neighbors and built directly upon experience and knowledge gained during the Phase II Loudon huff n’ puff project.

Research vs. Commercial

The Midwest Geological Sequestration Consortium (MGSC) Phase II research is different from what is expected at future commercial sites for a variety of reasons, such as: the scale of the Phase II pilot work was significantly smaller than a commercial-scale operation; the timing of Phase II pilot studies were shorter duration tests than 30-year operating projects; and the enhanced oil recovery (EOR) and enhanced coalbed methane (ECBM) implementation in Illinois Basin is currently limited and future operations are at present still under investigation. It remains a question as to whether or not these geologic storage options will reach commercial-scale in the Illinois Basin.

In Phase II, MGSC tested several monitoring, verification, and accounting (MVA) methods that were deployed to monitor atmospheric, near-surface, and subsurface information in order to identify potential events outside of natural variability. Application of these monitoring technologies provided significant insight into the effectiveness of field monitoring, especially in the shallow subsurface. The Phase II experiences influenced monitoring plan development for Phase III, which also utilized the opportunity to continue testing monitoring technologies that may not necessarily be deployed at commercial sites.

Based on experience gained in Phase II, Phase III, and through the Illinois Industrial Sources project (IL-ICCS), MGSC streamlined monitoring approaches and gained considerable understanding of baseline development and long-term monitoring. MGSC experience shows that commercial sites are less likely to use as many monitoring technologies as utilized in demonstration projects and are likely to choose proven technologies over options that are more experimental or research-oriented.

Lessons Learned

In Phase II work, the Midwest Geological Sequestration Consortium (MGSC) learned a lot about field operations, safety, management of working projects, working with industrial partners, and how to do site-specific stakeholder engagement that focused on landowners, regulators, and project developers. MGSC moved this whole process from site to site and expanded it in Phase III.

Phase II increased the capabilities of the MGSC staff because they were in the field learning as they worked on the pilot projects. As a result, MGSC had a lot more scientists who gained experienced with carbon capture and storage (CCS) project work as MGSC moved through Phase II projects to Phase III.

In Phase III, MGSC had the opportunity to test more monitoring technologies and to create monitoring plans from start to finish, and MGSC incorporated a risk-based approach to project development and execution. Risk assessments were conducted at multiple stages throughout Phase III to ensure project risks were mitigated and managed. One lesson learned as MGSC transitioned from Phase II to Phase III was that environmental compliance monitoring efforts need to be scaled appropriately for the project needs and may require additional automation to capture more continuous data streams over the long term. Additionally, regular compliance sampling (i.e., shallow groundwater sampling) would still be a monitoring requirement that would complement continuous monitoring efforts.