South-central Kansas CO₂ Project

DE-FE00006821-Final_report_wAppendices_1-4-18.pdf, Dec. 31, 2017 (Adobe Acrobat PDF file, 37.4 MB)

The objectives of this project are to understand the processes that occur when a maximum of 70,000 metric tonnes of CO₂ are injected into two different formations to evaluate the response in different lithofacies and depositional environments. The evaluation will be accomplished through the use of both in situ and indirect MVA (monitoring, verification, and accounting) technologies. The project will optimize for carbon storage accounting for 99% of the CO₂ using lab and field testing and comprehensive characterization and modeling techniques.

Site characterization and CO₂ injection should demonstrate state-of-the-art MVA tools and techniques to monitor and visualize the injected CO₂ plume and to refine geomodels developed using nearly continuous core, exhaustive wireline logs, and well tests and a multi- component 3D seismic survey. Reservoir simulation studies will map the injected CO₂ plume and estimate tonnage of CO₂ stored in solution, as residual gas, and by mineralization and integrate MVA results and reservoir models shall be used to evaluate CO₂ leakage. A rapid-response mitigation plan was developed to minimize CO₂ leakage and provide comprehensive risk management strategy. The CO₂ was supposed to be supplied from a reliable facility and have an adequate delivery and quality of CO₂. However, several unforeseen circumstances complicated this plan: (1) initially negotiated CO₂ supply facility went offline and contracts associated with CO₂ supply had renegotiated, (2) UIC Class VI permit proved to be difficult to obtain due to experimental nature of the project. Both subjects are detailed in separate deliverables attached to this report.

The CO₂ EOR and geologic storage in Mississippian carbonate reservoir was sucessully deployed. Approximately 20,000 metric tons of CO₂ was injected in the upper part of the Mississippian reservoir to verify CO₂ EOR viability in carbonate reservoirs and evaluate a potential of transitioning to geologic CO₂ storage through EOR. Total of 1,101 truckloads, 19,803 metric tons, average of 120 tonnes per day were delivered over the course of injection that lasted from January 9 to June 21, 2016. After cessation of CO₂ injection, KGS 2-32 well was converted to water injector and is currently continues to operate. CO₂ EOR progression in the field was monitored weekly with fluid level, temperature, and production recording, and formation fluid composition sampling.

As a result of CO₂ injection observed incremental average oil production increase is ~68% with only ~18% of injected CO₂ produced back. Simple but robust monitoring technologies proved to be very efficient in detection and locating of CO₂. High CO₂ reservoir retentions with low yields within actively producing field could help to estimate real-world risks of CO₂ geological storage for future projects. Wellington filed CO₂ EOR was executed in a controlled environment with high efficiency. This case study proves that CO₂ EOR could be successfully applied in Kansas carbonate reservoirs if CO₂ sources and associated infrastructure is available.

Recent developments in unconventional resources developments in Mid-Continent USA and associated large volume disposal of backflow water and resulted seismic activity have brought more focus and attention to the Arbuckle Group in southern Kansas. Despite the commercial interest, essential information about reservoir properties and structural elements is limited that has impeded managing and regulating disposal brought into the forefront by the recent seismicity in and near the areas of large volumes and rates of brine disposal.

The Kansas Geological Survey (KGS) collected, compiled, and analyzed available data, including well logs, core data, step rate tests, drill stem tests, 2D and 3D seismic data, water level measurements, and others types of data. Several exploratory wells were also drilled and core was collected and modern suites of logs were analyzed. Reservoir properties were populated into several site specific geological models. The geological models illustrate the highly heterogeneous nature of the Arbuckle Group. Vertical and horizontal variability results in several distinct hydro- stratigraphic units that are the result of both depositional and diagenetic processes.

Also, during the course of this project it has been demonstrated that advanced seismic interpretation methods can be used successfully for characterization of the Mississippian reservoir and Arbuckle saline aquifer. Analysis of post-stack 3D seismic data at the Mississippian reservoir showed the response of a gradational velocity transition. Pre-stack gather analysis showed that porosity zones of the Mississippian and Arbuckle reservoirs exhibit characteristic AVO response. Simultaneous AVO inversion estimated P- and S-Impedances. The 3D survey gather azimuthal anisotropy analysis (AVAZ) provided information on the fault and fracture network and showed good agreement to the regional stress field and well data. Mississippian reservoir porosity and fracture predictions agreed well with the observed mobility of injected CO₂ in KGS well 2-32. Fluid substitution modeling predicted acoustic impedance reduction in the Mississippian carbonate reservoir introduced by the presence of CO₂.

Seismicity in the United States midcontinent has increased by orders of magnitude over the past decade. Spatiotemporal correlations of seismicity to wastewater injection operations have suggested that injection-related pore fluid pressure increases are inducing the earthquakes. In this investigation, we examine earthquake occurrence in southern Kansas and northern Oklahoma and its relation to the change in pore pressure. The main source of data comes from the Wellington Array in the Wellington oil field, in Sumner County, KS, which has monitored for earthquakes in central Sumner County, KS since early 2015. The seismometer array was established to monitor CO₂ injection operations at Wellington field. Although no seismicity was detected in association with the spring 2016 Mississippian CO₂ injection, the array has recorded over 2,500 earthquakes in the region and is providing valuable understanding to induced seismicity. A catalog of earthquakes was built from this data and was analyzed for spatial and temporal changes, stress information, and anisotropy information. The region of seismic concern has been shown to be expanding through use of the Wellington earthquake catalog, and has revealed a northward progression of earthquake activity reaching the metropolitan area of Wichita. The stress orientation was also calculated from this earthquake catalog through focal mechanism inversion. The calculated stress orientation was confirmed through comparison to other stress measurements from well data and previous earthquake studies in the region. With this knowledge of the stress orientation, the anisotropy in the basement could be understood. This allowed for the anisotropy measurements to be correlated to pore pressure increases. The increase in pore pressure was monitored through time-lapse shear-wave anisotropy analysis. Since the onset of the observation period in 2010, the orientation of the fast shear-wave has rotated 90°, indicating a change associated with critical pore pressure build up. The time delay between fast and slow shear wave arrivals has increased, indicating a corresponding increase in anisotropy induced by pore pressure rise. In-situ near-basement fluid pressure measurements corroborate the continuous pore pressure increase revealed by the shear-wave anisotropy analysis over the earthquake monitoring period.

This research is the first to identify a change in pore fluid pressure in the basement using seismological data and it was recently published in the AAAS journal Science Advances (Nolte et al., 2017). The shear-wave splitting analysis is a novel application of the technique, which can be used in other regions to identify an increase in pore pressure. This increasing pore fluid pressure has become more regionally extensive as earthquakes are occurring in southern Kansas, where they previously were absent. These monitoring techniques and analyses provide new insight into mitigating induced seismicity's impact to society.

Q24_2017.pdf, Oct. 31, 2017 (Adobe Acrobat PDF file, 124 kB)

1. Wellington project UIC Class VI permit was put on hold and the well is classified as temporary abandoned UIC Class II well.
2. Three shallow water monitoring wells located in section 28 and perforated at 100 ft, 200 ft, and 50 ft depth were properly plugged and abandoned
3. Well site locations were restored
   1. KGS 1-32, 2-32, and 1-28 sites to be restored, but wells to be left open for future work and reentry. Berexco will not do anything with the wells for at least a year.
   2. Berexco assumed responsibility to plug/recomplete all 3 wells.
   3. Removed shallow and deep monitoring gauges and other equipment.
   4. Returned all leased equipment.
4. Seismometer network left in the field as-is with permission from operator and land owner.
5. Wellington seismometer array is on loan by IRIS-PASSCAL until September 30, 2018 with the possibility of extension per Pnina Miller.

Q23_2017.pdf, Aug. 1, 2017 (Adobe Acrobat PDF file, 886 kB)

1. Wellington project team continues earthquake activity with 15 seismometer stations on loan from IRIS, 3 KGS seismometers and regional USGS stations: over 2,100 earthquakes have been documented (magnitude 0.4-2.5) since April 2015, northward progression from Oklahoma is recorded, 2.1 TB of Wellington earthquake data provided to DOE NETL in July 2017, several publications are in preparations or have been accepted.
2. Since mid-April 2016, continuous (1-sec) baseline pressure measurements have been acquired in the perforated lower Arbuckle zone in the shut-in Class VI injector. Because of this monitoring, the well has not been retrofitted for installation of MVA tools (BP2 Milestone).
3. Berexco's financial and insurance teams are researching viable approaches for providing insurance or alternative methods to satisfy financial responsibility requirements for UIC Class VI permit.

Q22_2017.pdf, April 28, 2017 (Adobe Acrobat PDF file, 1.2 MB)

1. Day-to-day field operations similar to that reported in previous two quarters (Q20 and Q21) and are a continuation of Tasks 12-15
2. Continued monitoring of CO₂ plume movement
   1. Recorded volumes of CO₂ produced, oil, and brine recovered
   2. Only seven wells are being monitored based on past geochemical analyses that indicate the CO₂ plume has largely stabilized. Wells are currently being sampled for on-site (performed by KGS) and lab-based geochemical analyses (performed by Baker Chemicals). CO₂ gas quality measurements are being performed by Berexco staff.
3. The primary CO₂ plume has been managed by pressure maintenance including use of two nearby injection wells and targeted fluid withdrawal in eight surrounding wells. The CO₂ injection conforms largely to the stratigraphic architecture recorded in the geocellular model. Key work for the remainder of the CO₂-EOR phase is to continue measuring all inputs and outputs to obtain accurate measurement of CO₂ sequestered in the reservoir and the incremental oil produced from a single injection cycle.
4. On March 31, 2017 the daily CO₂ amount recorded was 1-8 MCFD. As of March 31, 2017, the cumulative produced CO₂ accounts for 18% of the injected volume (no change from December, 2016).
5. The re-processed 3D seismic was analyzed using AVAZ (Amplitude Variation with AZimuth) pre-stack methods which allowed mapping of fracture density and orientation in the Mississippian reservoir and the Arbuckle saline acquirer.
6. CO₂ fluid substitution seismic modeling in the Mississippian was completed.
7. Data collected for the project is constantly being updated and pre-processed for uploading into web-based interactive database catalogue.

Q21_2017.pdf, April 20, 2017 (Adobe Acrobat PDF file, 700 kB)

Q20_2016.pdf, Nov. 29, 2016 (Adobe Acrobat PDF file, 8 MB)

Q19_2016.pdf, Aug. 11, 2016 (Adobe Acrobat PDF file, 7 MB)

Q18_2016.pdf, May 17, 2016 (Adobe Acrobat PDF file, 12 MB)

Q17_2016.pdf, Feb. 9, 2016 (Adobe Acrobat PDF file, 13 MB)

Q16_2015.pdf, Oct. 12, 2015 (Adobe Acrobat PDF file, 13 MB)

Q15_2015.pdf, Aug. 12, 2015 (Adobe Acrobat PDF file, 4 MB)

Q14_2015.pdf, May 15, 2015 (Adobe Acrobat PDF file, 12 MB)

Q13_2015.pdf, Feb. 16, 2015 (Adobe Acrobat PDF file, 3 MB)

Q12_2014.pdf, Nov. 4, 2014 (Adobe Acrobat PDF file, 3 MB)

Q11_2014.pdf, revised Sept. 5, 2014 (Adobe Acrobat PDF file, 4 MB)

Q9_2014r.pdf, March 11, 2014 (Adobe Acrobat PDF file, 3 MB)

Q8_2013.pdf, Nov. 5, 2013 (Adobe Acrobat PDF file, 2 MB)

Q7_2013.pdf, May 6, 2013 (Adobe Acrobat PDF file, 925 kB)

Q6_2013.pdf, May 6, 2013 (Adobe Acrobat PDF file, 485 kB)

Q5_2013.pdf, Jan. 31, 2013 (Adobe Acrobat PDF file, 241 kB)

Q4_2012r2.pdf, Nov. 12, 2012 (Adobe Acrobat PDF file, 3 MB)

Q3_2012r.pdf, Revised Sept. 5, 2012 (Adobe Acrobat PDF file, 3.4 MB)

Q2_2012.pdf, May 2012 (Adobe Acrobat PDF file, 1.4 MB)

Q1_2012rev.pdf, March 2012 (Adobe Acrobat PDF file, 2.7 MB)