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.

注入地下地质层和溶剂辅助热采浅层油砂沥青中使用的溶剂的二氧化碳（CO2）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集可能是通过多种捕集机制发生的，例如溶解、残留相和矿化。最近，在油相和水相中具有互溶性的二甲醚等生物衍生化学品在溶剂辅助沥青热回收中引起了人们的兴趣。此外，由于沥青在高于 200oC 的高温下汽化，油砂中会产生或释放出大量的甲烷、二氧化碳和硫化氢。虽然用于沥青回收的注入溶剂部分随产生的液体回收，但这些化学品的一小部分以及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物质的长期命运。尽管过去十年取得了进展，但仍需要进一步研究，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物质的长期命运。 我的研究计划旨在增进对基本捕集机制的了解，例如二氧化碳的对流溶解和长期命运以及注入的化学物质或地下原位生成的化学物质。特别令人感兴趣的是计算工具的开发，可供油砂行业、政府组织和政策制定者用于二氧化碳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，已经开发出模型来估计储存地点加压盐水和二氧化碳的泄漏率。然而，用于估计注入和原位生成的化学品泄漏率的工具的开发仍处于起步阶段。特别是，缺乏适用于原位油砂提取过程的泄漏模型。 此外，寻找加速二氧化碳溶解度捕获并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工具，帮助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明智应用。特别是，对注入化学品的长期命运的新见解、潜在泄漏途径和机制的确定以及加速溶解度捕获的策略将是本研究的新贡献。此外，该项目还培养了5名本科生、2名硕士生和2名博士生。