Regional CO₂ sequestration capacity assessment for the coastal and offshore Texas Miocene interval

Abstract

Estimating regional geologic storage capacity potential for carbon dioxide will play an important role in determining the feasibility of widespread carbon capture and storage (CCS) programs in the United States and worldwide. The sandstone reservoirs of the Miocene Age located off the Texas coast in the northern Gulf of Mexico are a promising target for CCS due to favorable geologic properties (high porosity/permeability, effective traps and seals, etc.) and proximity to high carbon dioxide emission sources. The common method for regional storage capacity estimation involves the calculation of a pore volume which is modified by some discount or efficiency factor. Though efficiency factors have a large effect on calculated capacity, little work has been done to validate the use and effectiveness of these terms. In this paper we aim to provide an estimate for the storage potential of the coastal and offshore Texas Miocene interval using a common calculation methodology and to begin expanding on this calculation by developing and incorporating an additional sand picking refinement step. This step allows for an initial investigation into the accuracy and utility of typical efficiency factors and regional storage calculations. We find that in our study area, capacity that is calculated using the actual net sand thickness, or ‘net capacity’, is ∼25% less than capacity that is calculated using the total interval thickness, or ‘gross capacity’, though, ideally, the two should be equal. Discrepancies between the two calculations emphasize the large uncertainty inherent in efficiency factors and highlight the need for further investigation.

Carbon capture, utilization, and storage hub development on the Gulf Coast

“…The thick (1500-4500 m; 5000-15 000 ft) and relatively young and porous clastic Miocene stratigraphy has multiple regional confining intervals deposited during regional sea level transgressions. Considered together, these efforts document the excellent subsurface potential for both onshore and offshore geologic storage of CO 2 , with estimates of offshore storage in the Miocene-age stratigraphy of 129 Gt; 7 their Fig. 1), representing potentially decades of CO 2 storage capacity for nearby industrial sources.…”

“…1 This series of research experiments was one of the first transparent academic-led sequestration experiments in the United States, included dozens of national and international scientific collaborators, and resulted in over 50 peer-reviewed scientific publications. Despite the necessarily small injection masses (10s to 100 kton), 6 https://www.netl.doe.gov/projects/files/FENETLCO2TransportCostModel 2018ModelOverview_050818.pdf 7 5 See text for related Miocene CO 2 storage capacity studies offshore Texas; 7 Trevino and Meckel, 2017), suggesting decades of potential storage of current annual emissions in the region. Yellow cross symbol east of Houston indicates location of Frio CCS test site in Liberty County (2004,2006).…”

“…3). In this paper we focus on the suitability of storage in the offshore wedge, primarily in the state waters of Texas 7 and Louisiana. Offshore the regional subsurface geology has been mapped in detail for prospective CO 2 storage in saline formations for over a decade through a number of efforts funded by the US DOE National Energy Technology Laboratory (NETL) and the Texas General Land Office (GLO).…”

“…Additional development of commercial CCS projects addressing these industrial sources in the region would simultaneously serve multiple state and national interests by demonstrating the sustainability of and minimizing the environmental impacts of a suite of energy-related activities that play a major role in the future National energy and raw product supply chain. The suitability of the Gulf Coast for CCS has been recognized 7 by the Oil and Gas Climate Initiative (OGCI), which is a consortium of thirteen large integrated hydrocarbon energy producers that control approximately 30% of global hydrocarbon production, representing 17% of primary energy demand.…”

Influence of highly permeable faults within a low‐porosity and low‐permeability reservoir on migration and storage of injected CO2

“…CO 2 geological storage formations include depleted oil and gas fields, nonmineable deep coal seams, and deep saline aquifers. Among these, deep saline aquifers are often chosen as the most ideal reservoir because of advantages such as continuous and wide distribution, and large storage volume Zhang et al 2009;Rosenbauer & Thomas 2010;Hsieh et al 2013;Bu et al 2014;Wallace et al 2014;Yang et al 2014a,b). When selecting the CGS site, formations with high porosity and permeability are generally chosen as the reservoir.…”