Feasibility study, comparative analysis, and optimization of natural gas Huff-n-Puff processes in Duvernay and Eagle Ford formations

全球能源需求预计将增加，而常规资源的碳氢化合物产量一直在下降。这促使油气行业通过水力压裂作业开发非常规资源。加拿大拥有巨大的非常规资源，仅在阿尔伯塔省就有大约4250亿桶页岩油和致密油。然而，该行业面临着严重的经济和环境挑战，以实现这些资源的可持续发展。虽然水平钻井和多级水力压裂已经成功地从致密资源中释放出了油气，但其一次采收率非常低（仅为原始产油量的5-10%）。因此，油气行业需要采用提高采收率（EOR）技术来提高此类作业的效率。将采出的天然气注入枯竭的非常规储层被认为是提高非常规储层采收率的一种有潜力的技术。该研究旨在进行系统的实验室实验和数学分析，以进行Duvernay和EagleFord地层循环天然气注入（huffn - puff）的可行性研究、对比分析和优化。这两组烃源岩具有相似的地质、岩石学和岩石物理性质。支助组织将结合现场数据分析实验室结果，以便在两个地层中设计最佳的试点试验。三名博士和两名理学硕士学生以及一名博士生将进行拟议的实验室和模型研究。阿尔伯塔大学的团队将与支持组织的专家合作，制定指导方针，1)根据岩石和流体性质确定候选井，2)优化huffn - puff流体的成分和操作参数。该研究团队将获得相关的技术专长，为加入加拿大油气行业做好准备，并继续负责任地开发该国的非常规资源。

The global energy demand is expected to increase while the hydrocarbon production rate from conventional resources has been declining. This has motivated the industry to develop unconventional resources by hydraulic fracturing operations. Canada has massive unconventional resources with an estimated 425 billion barrels of shale and tight oil in-place in Alberta alone. However, the industry is facing serious economical and environmental challenges for sustainable development of such resources. Although horizontal drilling and multi-stage hydraulic fracturing have successfully unlocked hydrocarbon production from tight resources, the primary oil recovery factors are very low (5-10% of the original oil in-place). Therefore, the industry needs to apply enhanced oil recovery (EOR) techniques to improve the efficiency of such operations. Injecting the produced natural gas into the depleted unconventional reservoirs has been considered as potential technique to improve oil recovery factor of these reservoirs.The proposed research aims to conduct systematic laboratory experiments and mathematical analyses for feasibility study, comparative analysis, and optimization of cyclic natural gas injection (Huff-n-Puff) in the Duvernay and EagleFord formations. The two formations are source rocks with similar geological, petrographic, and petrophysical properties. The laboratory results will be analyzed in conjunction with the field data to design optimum pilot tests in the two formations by the supporting organizations. Three PhD and twoMSc students and one PDF will conduct the proposed laboratory and modelling studies. The University of Alberta team will collaborate with experts from the supporting organizations to develop guidelines 1) to identify candidate wells based on their rock and fluid properties, and 2) to optimize the composition of Huff-n-Puff fluids and operational parameters. The research team will acquire relevant technical expertise to be well-poised to join the Canadian oil and gas industry, and continue the responsible development of the nation's unconventional resources.