Elemental characterization of thermal-hydraulic-mechanical-chemical properties of caprock and interbedded shale under SAGDOX process in Athabasca oil sands

蒸汽辅助重力泄油（SAGD）是一种从加拿大阿尔伯塔的清洁油砂储层中原位回收沥青的商业方法。在低品质油砂储层中，蒸汽区的空间范围和重力泄油受到储层中的互层页岩层的显著阻碍。 SAGD变得不经济，特别是在当前的低油价环境下，在低质量储层中。后SAGD氧化工艺（SAGDOX）是提高低品质油砂油藏采收率的潜在可行的原位采收工艺之一。在SAGDOX工艺中，氧气与蒸汽在每隔一个SAGD水平平行注入井中共注入，并且反应前沿处的氧化温度可以在400-600 ℃的范围内，这比SAGD中遇到的200-300 ℃的温度更高。在这样的高温下，夹层页岩可能分解，并且可以提高排水效率以增加蒸汽增长和油排水。 为了确保SAGDOX的成功和环境保护，盖层必须能够承受现场遇到的高温和孔隙压力。迄今为止，对高温和孔隙压力对盖层和互层页岩材料的结构和水力性质的理解有限。 拟议研究的总体目标是建立一个强大的科学知识基础，以促进我们对热采过程中高温对盖层和夹层页岩行为的影响的理解。研究成果包括新知识和新模型，所有这些都将使能源运营商和监管机构能够理解，预测和管理重油开采过程。阿尔伯塔的油砂是加拿大最大的自然资源之一。SAGD和其他混合SAGD等原位热采工艺对于加拿大可利用的大量资源的开采越来越重要。这项研究的工作推动SAGD恢复向前发展，支持开发可行，经济，安全和可持续的恢复方法。

Steam assisted gravity drainage (SAGD) is a commercially available in-situ recovery process for bitumen from clean oil sands reservoirs in Alberta, Canada. In low-quality oil sands reservoirs, the spatial extent of the steam zone and the gravity drainage are significantly impeded by interbedded shale layers in the reservoir. SAGD becomes uneconomical, particularly in the current low oil price environment, in low-quality reservoirs. A post SAGD oxidation process (SAGDOX) is one of the potentially viable in-situ recovery processes to improve the recovery for low-quality oil sands reservoirs. In SAGDOX process, oxygen gas is co-injected with steam in every other SAGD horizontal parallel injector well, and the oxidation temperature at the reaction front may be in the range of 400-600 C, which are higher temperatures than those encountered in SAGD of 200-300 C. At such high temperatures, interbedded shales may disintegrate, and the drainage efficiency may be enhanced to increase steam growth and oil drainage. To ensure the success of SAGDOX and protection of the environment, the caprock must be able to withstand the high temperatures and pore pressures encountered in the field. To date, there is limited understanding of high temperatures and pore pressures on the structural and hydraulic properties of caprock and interbedded shale materials. The overall objective of the proposed research is to develop a strong scientific knowledge base to advance our understanding of the effect of high temperatures on behaviour of caprock and interbedded shale in thermal recovery processes. The research outcomes include new knowledge and new models, all of which will enable energy operators and regulators to understand, predict and manage the heavy oil recovery processes. Oil sands in Alberta is one of the largest natural resources in Canada. In-situ thermal recovery processes such as SAGD and other hybrid SAGD are increasingly important to the recovery of accessible vast resources in Canada. The work of this research moves SAGD recovery forward, supporting the development of recovery methods that are feasible, economical, safe and sustainable.