STATEWIDE ASSESSMENT OF CO2 STORAGE RESOURCES FOR THE LOWER PALEOZOIC STRATA, OKLAHOMA

Abstract

To reach the Paris Agreement’s goal to keep the rise in global surface temperature to below 2 °C above pre-industrial levels, carbon capture, utilization, and storage (CCUS) will be required for large quantities of CO2. Oklahoma’s unique history as an oil and gas producing state makes it an ideal location for CCUS. While the United States Geological Survey (USGS) completed and released a national assessment of geologic carbon dioxide storage resources (U.S. Geological Survey Geologic Carbon Dioxide Storage Resources Assessment Team, 2013) which is an initial assessment of storage resources on a regional basis, there have been no statewide assessments of CO2 storage for individual reservoirs at the state level. This dissertation attempts to fill that void by determining the spatial distribution of lithology, pore volume, and CO2 storage resources for the: 1) Arbuckle and Timbered Hills group (Arbuckle zone). 2) Simpson Group and Viola Limestone (Ordovician zone). 3) Hunton Group and Misener Sandstone (Hunton zone). Due to the historical correlation between wastewater injection and induced seismicity in the Arbuckle zone, Chapter 1 also includes areas of high risk for induced seismicity by integrating well data, wastewater injection volumes, basement-seated faults, and historical earthquake locations and magnitudes. Chapter 2 highlights specifically the distribution of the sandstone reservoir, which is the intended target for CCUS. Chapter 3 on the Hunton zone uses supervised machine learning methods to generate synthetic well logs so that lithology predictions could be made for additional wells in the dataset. Key findings include 1) Areas of enhanced porosity in the Arbuckle zone and areas at high risk of induced seismicity due to basement faulting and proximity to wastewater injection wells. 2) Areas with thick, high porosity Ordovician sandstone at depths above 10,000 ft, and 3) Areas where the high porosity dolomite develops within the Hunton zone, and where pressure depletion due to hydrocarbon production has the potential to lead to increased storage resources. Overall, this is the most detailed study to date of lithology, pore space, and CO2 storage resources for the state of Oklahoma.