East Bend Site - Validation Phase
During fall 2006 through fall 2009, the Validation Phase, the MRCSP conducted a geologic field demonstration in the Cincinnati Arch province at Duke Energy’s East Bend Generating Station in Rabbit Hash, Kentucky. The project entailed injecting a small amount of CO₂ --about 1,000 tons. The CO₂ was obtained from Praxair, a regional supplier of gases. The activities undertaken in this test are described in the following project snapshots.
The demonstration involved injection into a deep saline reservoir in the area, including targets in the Mt. Simon Sandstone which underlies much of the Midwestern region. Reservoirs in the Mt. Simon formation are located between 3,000-4,000 feet below the surface. As is the case in all deep saline injection tests, these reservoirs were located way below drinking water supplies, which are about 100 feet deep in this part of the Cincinnati Arch. Appropriate drilling and injection permits were obtained from US EPA Region 4, the agency with jurisdiction over the underground injection program in Kentucky. The project team took core samples and conducted reservoir tests in the well. Information from these tests was used to assess the nature and strength of the underground rock and determine the maximum acceptable pressure for injection.
The project entailed injecting a small amount of CO₂ --about two or three tanker trucks per day over a period of a few months.
CO₂ Injection Testing and Monitoring
Approximately 1,000 metric tons of carbon dioxide was injected into the Mt. Simon Sandstone in September 2009. The carbon dioxide was purchased from a commercial source. Wireline tools, system pressure, temperature, brine geochemistry, and groundwater monitoring were used to monitor the injection, delineate the movement of carbon dioxide in the formation, and confirm that the injection was proceeding as planned. Below are some pictures from the recently completed test.
Brian Weisker, Generating Station Manager, stands by the injection well prior to the field test.
A temporary supply of carbon dioxide was stored on site in storage tanks. The carbon dioxide that was used for this test was the same in composition as that routinely used in the food industry. It was transported as a liquid by standard delivery trucks.
The actual injection of carbon dioxide was not visible because injection took place at the bottom of the well more than a half mile below ground. The injection well is shown in the center of the picture.
MRCSP Open House
The MRCSP held an open-house forum to share information about the East Bend project with neighbors. The forum drew about 30-40 participants. MRCSP hosted several stations that provided information about different aspects of the project and enabled people to talk directly to members of the MRCSP research team.
The materials that were used at the information stations included a poster describing the well drilling
at the East Bend site; an enlarged well diagram
of the actual well at the site; and a poster showing the results of the test well logging
conducted while the well was being drilled. These and other posters that have been used in previous meetings to help explain the project were shared at the meeting. In addition, information about what to expect
was provided on the website.
June - July 2009
Well Logging and Testing
Drilling of the injection well for the East Bend field test began after receiving a drilling permit from the Kentucky Division of Oil and Gas in June 2009. The picture below shows the drilling rig in operation.
The injection well was drilled to a depth of 3,700 feet below the surface. The well design included continuous strings of steel casing that extend from about 3,600 ft back to the ground surface.
During the drilling process, 90 feet of full core rock samples were taken from the well. A single 30-foot-long core sample of the caprock, or seal formation (Eau Claire Shale) and two 30-foot-long cores of the storage formation (Mt. Simon Sandstone) were collected. The cores were marked with depth information, cut into 3-foot long sections, placed in cores bags, and placed in core boxes for shipment to the laboratory. The picture below shows a portion of the core sample from the target storage formation, the Mt. Simon Sandstone. Tests will be conducted on the core samples from both the storage zone and the caprock zone to assess the suitability of the well for injection and as a basis for the injection plan.
After the well logging and testing were completed, a mechanical integrity test, which was observed by an inspector delegated by the U.S. EPA Region 4, the regulatory authority, was successfully completed on the well casing. A report on the test was submitted to U.S. EPA Region 4 for their approval.
In November, 2006 the MRCSP worked with Appalachian Geophysical to conduct a seismic survey in the area around the East Bend plant. Information from this survey is being used to develop a geophysical image of the underground geology. These are some pictures from the survey.
These are Vibroseis trucks that induce vibrations into the ground. In the picture above, they are traversing a cornfield (with the farmer’s permission, of course). The picture below is a close-up shot of the plate that generates vibrations.
The vibrations from the plate create echoes that, when picked up by sensors called geophones like those shown below, form an image of the geologic layers. This is much like ultrasound practices used in medicine but on a different scale.
The soundwaves picked up by the sensors are transmitted to a receiver in a computer known as a data logger which translates the sounds into a visual image of the subsurface geology as seen below. The resulting data are being interpreted through a collaborative effort of the MRCSP team, including the Kentucky and Indiana State Geological surveys, Battelle, and Appalachian Geophysical to evaluate the presence or absence of geologic features on interest.
The following illustration is an example of the output generated from the seismic survey. It shows the pathways that the vibroseis trucks followed in developing the seismic survey for the Duke Energy’s East Bend plant. This map is used in characterizing the depth and thickness of the Mount Simon Sandstone, a prevalent porous potential CO₂ storage reservoir in this region. The colors show the time of travel for the seismic waves (an indicator of layer depth) to the Mt. Simon sandstone layer. As the color darkens to purple, the depth to the sandstone layer increases. You can see that the Mt. Simon layer is deeper toward the west as this layer heads towards the Illinois Basin.
The next likely activity at the site will be drilling of a test well, after a drilling permit is obtained, to evaluate individual rock layers and calibrate the seismic survey data.
The following link is to a video clip for a similar seismic survey that was completed for the Appalachian Basin project near FirstEnergy’s R.E. Burger Plant. This video shows all of the stages of the process.
The MRCSP held an open-house forum to share information about the East Bend project with local neighbors. The forum drew about 30 participants. MRCSP created several stations that provided information about different aspects of the project and enabled people to talk directly to members of the MRCSP research team.