Subsurface Property Rights: Implications for Geologic CO2 Sequestration

The impact of carbon geological sequestration

Reactive transport modeling for CO 2 geological sequestration

ABSTRACT: The United States Environmental Protection Agency (USEPA) developed the Underground Injection Control (UIC) Class VI regulations under the authority of the Safe Drinking Water Act (SDWA), specifically for the injection of carbon dioxide into deep subsurface formations for the purpose of geologic sequestration. The Class VI regulations are built upon the long-standing protective framework of the UIC Program to prevent the endangerment of underground sources of drinking water, with requirements that are tailored to address issues unique to carbon dioxide injection. These include requirements that address the large injection volumes anticipated at geologic sequestration projects, higher reservoir pressures relative to other injection formations, and the behavior of the injected carbon dioxide (e.g., its relative buoyancy, mobility within subsurface geologic formations, and corrosivity in the presence of water). The regulations establish technical requirements for geologic site characterization, area of review, corrective action on artificial penetrations, well construction, testing and monitoring, reporting, well plugging, post-injection site care, site closure, and financial responsibility.

SYNOPSIS The mining industry has evolved, such that the means of production that were once in the hands of major players or power houses have become equally accessible to smaller entrants, i.e. junior mining companies and contract miners. Contract mining involves contractual relationships between mine owners or mineral right holders and third parties to conduct mining activities on behalf of the right holders. The current mining income tax legislation has been a considerable obstacle to contract miners. Under its terms, they have been viewed as mining on behalf of third-party mineral rights holders. As such, expenditure incurred in relation to contract mining activities was often disallowed by the South African Revenue Service (SARS). However, the recent judgement of the Supreme Court of Appeal, Benhaus Mining (Pty) Ltd v CSARS 2020 (3) SA 325 (SCA) (Benhaus), rightfully or wrongfully, appears to provide clarity regarding the fate of contract miners' involvement in the mining value chain. The taxpayer, a contract miner, was held to be conducting mining operations within the meaning of S15(a) read with si of the Income Tax Act 58 of 1962 (the Income Tax Act). This paper looks at how contract mining has traversed the mining tax landscape, the implications of the Benhaus judgment, and stresses the necessity for clear policy reform to the mining tax regime and equally to legislation framed to give effect to these policies. Keywords: Contract mining, owner mining, tax, DMRE, mining regime reforms.

Research Article| January 01, 2010 Geologic carbon sequestration in Wyoming: prospects and progress Carol D. Frost; Carol D. Frost * 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, U.S.A *Correspondence should be addressed to: frost@uwyo.edu Search for other works by this author on: GSW Google Scholar Anne C. Jakle Anne C. Jakle 2Ruckelshaus Institute of Environment and Natural Resources, University of Wyoming, Laramie, Wyoming 82071, U.S.A. Search for other works by this author on: GSW Google Scholar Author and Article Information Carol D. Frost * 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, U.S.A Anne C. Jakle 2Ruckelshaus Institute of Environment and Natural Resources, University of Wyoming, Laramie, Wyoming 82071, U.S.A. *Correspondence should be addressed to: frost@uwyo.edu Publisher: University of Wyoming Received: 05 Aug 2010 Revision Received: 22 Sep 2010 Accepted: 22 Sep 2010 First Online: 09 Mar 2017 Online Issn: 1555-7340 Print Issn: 1555-7332 UW Department of Geology and Geophysics Rocky Mountain Geology (2010) 45 (2): 83–91. https://doi.org/10.2113/gsrocky.45.2.83 Article history Received: 05 Aug 2010 Revision Received: 22 Sep 2010 Accepted: 22 Sep 2010 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Carol D. Frost, Anne C. Jakle; Geologic carbon sequestration in Wyoming: prospects and progress. Rocky Mountain Geology 2010;; 45 (2): 83–91. doi: https://doi.org/10.2113/gsrocky.45.2.83 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyRocky Mountain Geology Search Advanced Search Abstract Coal supplies nearly 50 percent of electricity generation in the United States and 25 percent of the global energy supply; Wyoming produces approximately 40 percent of the coal consumed in the United States. It is likely that near-term energy strategies will include coal and other fossil energy sources in the fuel mix, therefore mitigating carbon dioxide emissions through geologic carbon capture and sequestration (CCS) is crucial. Here we discuss the current state of CCS technology across the globe and its future potential for development. We also outline the current regulatory structure for CCS in the United States, specifically Wyoming, and we introduce the study undertaken by University of Wyoming researchers and their collaborators to characterize Paleozoic deep saline aquifers on the Moxa Arch in southwestern Wyoming for long-term geologic carbon storage. The research presented in this special issue of Rocky Mountain Geology and future research that builds on these findings, such as the site characterization project underway on the Rock Springs Uplift in Wyoming, will be important steps to advance successful CCS technologies at a rate and scale that can make a meaningful impact on greenhouse gas emissions and to construct commercial geologic sequestration projects in the Rocky Mountain West. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

An accurate estimation of the CO2 storage capacity in saline aquifers is critical for the successful implementation of geological CO2 sequestration projects. Although volumetric methods provide quick and accurate estimates for the storage capacity, the storage efficiency factor (SEF) relies on empirical correlations or computationally expensive numerical simulations. To overcome these limitations, this study proposed a novel regression-based prediction approach for directly predicting SEF in vertical and horizontal well scenarios using simulation-derived data. Four regression models were developed: multi-linear regression (MLR), exponential (Exp), and response surface methodology models (RSM-1 and RSM-2). Among them, the RSM-2 models, which incorporate linear, interaction, and quadratic terms, demonstrated the highest accuracy, achieving mean absolute percentage errors of 1.1% and 3.4% for vertical and horizontal wells, respectively. Compared to prior empirical approaches, the RSM-2 model provided more precise and consistent predictions, with a narrower SEF distribution range and reduced uncertainty, enhancing its suitability for site screening and storage planning. The models were applied to two reservoirs in the Pohang Basin, Southeast Korea, and yielded storage capacity estimates within 5% of full-physics simulation results, confirming their validity and reliability. These models provide a cost-effective and time-efficient alternative to conventional simulations and are particularly advantageous in early-stage feasibility studies and large-scale CO2 storage assessments. Future work will expand these models to accommodate more complex reservoir conditions and enhance their generalizability across diverse geological settings.

Applicability of aquifer impact models to support decisions at CO2 sequestration sites

Numerical modeling of CO2 injection into a typical US Gulf Coast anticline structure

An efficient deep learning-based workflow for real-time CO2 plume visualization in saline aquifer using distributed pressure and temperature measurements

The West Coast Regional Carbon Sequestration Partnership (WESTCARB), in collaboration with Shell Oil Co. performed site characterization for a potential small-scale pilot test of geologic sequestration of carbon dioxide (CO2). The site area, know as Montezuma Hills, is near the town of Rio Vista in northern California. During the process of injection at a CO2 storage site, there is a potential for seismic events due to slippage upon pre-existing discontinuities or due to creation of new fractures. Observations from many injection projects have shown that the energy from these events can be used for monitoring of processes in the reservoir. Typically, the events are of relatively high frequency and very low amplitude. However, there are also well documented (non-CO2-related) cases in which subsurface injection operations have resulted in ground motion felt by near-by communities. Because of the active tectonics in California (in particular the San Andreas Fault system), and the potential for public concern, WESTCARB developed and followed an induced seismicity protocol (Myer and Daley, 2010). This protocol called for assessing the natural seismicity in the area and deploying a monitoring array if necessary. In this report, we present the results of the natural seismicity assessment and the results of an initial temporary deployment of two seismometers at the Montezuma Hills site. Following the temporary array deployment, the project was suspended and the array removed in August of 2010.

Geological carbon sequestration (GCS) involves injecting CO 2 into subsurface geological formations for permanent storage. Numerical simulations could guide decisions in GCS projects by predicting CO 2 migration pathways and the pressure distribution in storage formation. However, these simulations are often computationally expensive due to highly coupled physics and large spatial-temporal simulation domains. Surrogate modelling with data-driven machine learning has become a promising alternative to accelerate physics-based simulations. Among these, the Fourier neural operator (FNO) has been applied to three-dimensional synthetic subsurface models. Despite its good accuracy in simulating CO 2 plume migration, it requires large computational resources in training and also lacks generalizability. Here, to further improve performance, we have developed a nested Fourier-DeepONet by combining the expressiveness of the FNO with the modularity of a deep operator network (DeepONet). This new framework is twice as efficient as a nested FNO for training and has at least 80% lower GPU memory requirement due to its flexibility to treat temporal coordinates separately. These performance improvements are achieved without compromising prediction accuracy. In addition, the generalization and extrapolation ability of nested Fourier-DeepONet beyond the training range has been thoroughly evaluated. Nested Fourier-DeepONet outperformed the nested FNO for extrapolation in time with more than 50% reduced error. It also exhibited good extrapolation accuracy beyond the training range in terms of reservoir properties, number of wells, and injection rate.

A group of scientists from six countries (France, Netherlands, Norway, Saudi Arabia, UK and the US) met over three days in September 2017 in Houston, Texas, to brainstorm and debate the most promising research directions needed to make breakthroughs in the areas of injectivity and capacity that currently pose challenges to carrying out large-scale (gigatonnes CO2 per year) geologic carbon sequestration. Several CO2 storage projects around the world have demonstrated the feasibility of injecting and storing CO2 at the mega-tonne per year scale. These include the long-running Sleipner project (Norway) which started in 1996 and which has stored ∼17 Mt of CO2 to date, and the Illinois Basin Decatur Project (USA) which has stored approximately 1 Mt of CO2. New projects have started over the last few years, including the QUEST project in Canada, the Gorgon project in Australia, and the Industrial Carbon Capture and Storage (ICCS) project at Decatur, Illinois, which will inject 1 Mt CO2/yr. These projects along with a wealth of injection experience from the oil and gas industry over decades, supported by an extensive literature of theory and modelling analyses, provide confidence in the subsurface storage concept intrinsic to CCUS.

<p>Gas leakage from deep geologic storage formations to the Earth’s surface is one of the main hazards in geological carbon sequestration and storage. Permeable sediment covers or natural and artificial pathways, such as faults and well structures, are the main factors controlling surface leakages. Therefore, the characterization of natural systems, where large amounts of CO<sub>2</sub> are released, can be helpful for understanding the effects of potential gas leaks from storage carbon systems. In this framework, we propose a combined use of geoelectrical investigations (i.e., resistivity tomography and self-potential surveys) for characterizing natural CO<sub>2</sub> leakage areas, as well as gas storage sites. Such methodologies appear to be among the most suitable for revealing spatial distributions of carbon dioxide and monitoring subsurface fluid migration processes, because of the strong dependence of the electrical properties of water-bearing permeable rock, or unconsolidated materials, on many factors relevant to CO<sub>2</sub> storage (i.e., porosity, fracturing, water saturation, etc.). Indeed, the electric resistivity of porous water-bearing sediments decreases significantly when CO<sub>2</sub> dissolves in pore-water, in contrast to the effect in the gas phase and supercritical CO<sub>2</sub>, while the anomalous concentrations of natural electric charge are directly related to carbon dioxide migration along porous and fractured rock systems. The effectiveness of the suggested multi-methodological geoelectrical approach is tested in some areas of natural CO<sub>2</sub> degassing located in the Southern Apennines (Italy), which could represent natural analogues of gas storage sites. Specifically, electrical resistivity and self-potential surveys are targeted at reconstructing shallow buried fracture networks in the cap-rock and detecting preferential CO<sub>2</sub> migration pathways. Our findings are promising for imaging the CO<sub>2</sub> plume within a carbon storage reservoir and for identifying possible CO<sub>2</sub> leakages through the cap-rock formation, suggesting that the proposed approach can be very helpful also for the monitoring of carbon sequestration systems.  </p>

Divided ownership has been shown to dilute economic incentives in a variety of contexts. Split estate, or severed mineral rights, is a widely-held form of divided ownership and has been a topic of recent policy interest. A natural experiment created by federal mineral ownership established due to forces unrelated to the natural resource being exploited is studied to avoid the endogeneity problems found on private minerals. Using well-level production data from coalbed methane (CBM) wells in Wyoming during the years 1987-2006, wells on federal minerals with private surface are compared to those on federal minerals with federal surface. Delays in development on split estate are found; maximum production is somewhat lower but cumulative production is higher. Some support is found for strategic incentives firms face regarding property rights. The role of the accommodation doctrine in preventing holdup is discussed.

Capability of underground carbon dioxide storage to confine and sustain injected CO2 for a long period of time is the main concern for geologic CO2 sequestration. If a leakage from a geological CO2 sequestration site occurs, it is crucial to find the approximate amount and the location of the leak, in a timely manner, in order to implement proper remediation activities. An overwhelming majority of research and development for storage site monitoring has been concentrated on atmospheric, surface or near surface monitoring of the sequestered CO2 . This study aims to monitor the integrity of CO2 storage at the reservoir level. This work proposes developing in-situ CO2 Monitoring and Verification technology based on the implementation of Permanent Down-hole Gauges (PDG) or “Smart Wells” along with Artificial Intelligence and Data Mining (AI&DM). The technology attempts to identify the characteristics of the CO2 leakage by de-convolving the pressure signals collected from Permanent Down-hole Gauges (PDG). Citronelle field, a saline aquifer reservoir, located in the U.S. was considered as the basis for this study. A reservoir simulation model for CO2 sequestration in the Citronelle field was developed and history matched. PDGs were installed, and therefore were considered in the numerical model, at the injection well and an observation well. Upon completion of the history matching process, high frequency pressure data from PDGs were generated using the history matched numerical model using different CO2 leakage scenarios. Since pressure signal behaviors were too complicated to de-convolute using any existing mathematical formulations, a Machine Learning-based technology was introduced for this purpose. An Intelligent Leakage Detection System (ILDS) was developed as the result of this effort using the machine learning and pattern recognition technologies. The ILDS is able to detect leakage characteristics in a short period of time (less than a day from its occurrence) demonstrating the capability of the system in quantifying leakage characteristics subject to complex rate behaviors. The performance of ILDS is examined under different conditions such as multiple well leakages, cap rock leakage, availability of an additional monitoring well, presence of pressure drift and noise in the pressure sensor and uncertainty in the reservoir model.