Mathematical Modeling of the Fate of the Injected and In-Situ Generated Gases in Subsurface Geological Formations

地下地质构造中注入气体和原位生成气体命运的数学模型

• 批准号: RGPIN-2020-04051
• 负责人: Hassanzadeh, Hassan
• 金额: $ 2.4万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716785
• 关键词: Mathematical; Modeling; Fate; Injected; Situ

Risk of leakage of carbon dioxide (CO2) injected into subsurface geological formations and solvents used in solvent-aided thermal recovery of bitumen from shallow oil sands is one of the major environmental challenges. Permanent trapping of these chemicals in subsurface may occur by several trapping mechanisms such as dissolution, residual phase, and mineralization. Recently, bio-derived chemicals such as dimethyl ether with mutual solubility in oleic and aqueous phases have gained interest in solvent-aided thermal recovery of bitumen. In addition, significant volumes of methane, carbon dioxide, and hydrogen sulfide are generated or liberated from oil sands as a result of steaming of bitumen at high temperatures greater than 200oC. While injected solvents for bitumen recovery are partially recovered with the produced fluids, a fraction of these chemicals along with the generated gases will remain in subsurface with potential risk of leakage to the groundwater in long term. The focus of my research is to develop models to study the long-term fate of the injected or in-situ generated chemicals in subsurface. While progress has been made in the past decade, further research is required to develop a better understanding of the trapping mechanisms and gain insight into the long-term fate of the injected CO2 and other chemicals. My research program aims to advance the knowledge of fundamental trapping mechanisms such as convective dissolution and long-term fate of CO2 and injected chemicals or in-situ generated chemicals in subsurface. Of particular interest is the development of computational tools that can be used by oil sands industry, governmental organizations, and policy makers for risk assessment of CO2 and environmental impact assessment of solvent injection for in-situ extraction of bitumen from oil sands. Recently, models have been developed for estimation of the rate of leakage of pressurized brine and CO2 from storage sites. However, development of tools for estimation of the rate of leakage of the injected and in-situ generated chemicals is still very much in its infancy. In particular, leakage models with applications to in-situ oil sands extraction processes are lacking. In addition, finding ways to accelerate solubility trapping of CO2 and reduce risk of leakage by acceleration of convective dissolution requires further research. This research develops knowledge and provides tools that help safe implementation of CO2 and acid gas sequestration as well as informed application of solvents for in-situ bitumen extraction from oil sands. In particular, new insights into the long-term fate of injected chemicals, determination of potential leakage pathways and mechanisms, and strategies to accelerate solubility trapping will be novel contributions of this research. In addition, this program provides training for 5 Undergraduate, 2 MSc, and 2 PhD students.

注入地下地质构造的二氧化碳（CO2）和用于从浅层油砂中溶剂辅助热回收沥青的溶剂的泄漏风险是主要的环境挑战之一。这些化学物质在地下的永久捕获可能通过多种捕获机制发生，例如溶解、残留相和矿化。最近，生物衍生的化学品，如二甲醚，具有互溶性的油相和水相已经在溶剂辅助热回收沥青的兴趣。此外，由于沥青在高于200 ℃的高温下汽蒸，油砂中产生或释放出大量甲烷、二氧化碳和硫化氢。虽然用于沥青回收的注入溶剂与产出的流体一起被部分回收，但这些化学品的一部分沿着所产生的气体将保留在地下，长期存在泄漏到地下水的潜在风险。 我的研究重点是开发模型来研究地下注入或原位生成的化学品的长期命运。虽然在过去十年中取得了进展，但需要进一步研究，以更好地了解捕获机制，并深入了解注入的二氧化碳和其他化学品的长期命运。 我的研究计划旨在推进基本捕获机制的知识，如对流溶解和CO2的长期命运和注入的化学品或地下原位生成的化学品。特别令人感兴趣的是，可用于油砂工业，政府组织和政策制定者的计算工具的开发，用于CO2的风险评估和从油砂中原位提取沥青的溶剂注入的环境影响评估。 最近，已经开发了模型，用于估计加压盐水和CO2从储存地点的泄漏率。然而，用于估算注入的和就地产生的化学品的泄漏率的工具的开发仍处于起步阶段。特别是，泄漏模型与应用程序，在现场油砂提取过程中缺乏。 此外，寻找加速CO2溶解度捕获和通过加速对流溶解来降低泄漏风险的方法需要进一步研究。 这项研究开发了知识，并提供了有助于安全实施二氧化碳和酸性气体封存以及从油砂中原位提取沥青的溶剂的知情应用的工具。特别是，新的见解注入化学品的长期命运，确定潜在的泄漏途径和机制，以及战略，以加速溶解度捕获将是这项研究的新贡献。此外，该计划还为5名本科生，2名硕士生和2名博士生提供培训。