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

蒸汽辅助重力排水(SAGD)是一种从加拿大艾伯塔省清洁油砂储层中就地回收沥青的商业可用工艺。在低品质油砂油藏中，页岩夹层对蒸汽带和重力排水的空间范围有明显的阻碍作用。SAGD变得不经济，特别是在当前低油价的环境下，在低质量的油藏中。SAGD后氧化工艺(SAGDOX)是提高低品质油砂油藏采收率的潜在可行的原地采油工艺之一。在SAGDOX工艺中，每隔一口SAGD水平平行注水井，氧气与蒸汽共注，反应前沿的氧化温度可能在400-600℃之间，高于SAGD中200-300℃的温度。在这样的高温下，夹层页岩可能会解体，从而提高排水效率，以增加蒸汽的增长和石油的排放。为了确保SAGDOX的成功和保护环境，盖层必须能够承受野外遇到的高温和孔隙压力。到目前为止，人们对高温和孔压对盖层和互层页岩材料的结构和水力性质的了解有限。 拟议研究的总体目标是发展强大的科学知识基础，以促进我们对高温对热采过程中盖层和互层页岩行为的影响的了解。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了解、预测和管理稠油开采过程。艾伯塔省的油砂是加拿大最大的自然资源之一。原地热回收工艺，如SAGD和其他混合SAGD，对于加拿大可获得的大量资源的回收越来越重要。本研究的工作推进了SAGD回收的进程，为开发可行、经济、安全、可持续的回收方法提供了支持。

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.