Evaluations of CO2/lean gas huff'n'puff pilot opportunities in liquid-rich shale: an economically viable option for reducing Canada's greenhouse gas emissions?

富含油气液体的页岩(LRS)区块是目前北美最热门的非常规油气藏目标。在艾伯塔省，加拿大石油行业对蒙特尼低渗透粉砂岩和杜维奈页岩富含液体的地区非常感兴趣，但开发重点是多裂缝水平井(MFHW)的主要枯竭，预计碳氢化合物液体采收率较低。此外，目前的恢复过程效率低下，没有提供减少艾伯塔省温室气体(GHG)排放的解决方案。一种可能的解决方案是将二氧化碳注入MFHW，或将从储油层中回收的贫气(富含CH4)重新注入MFHW，以同时提高液态烃回收率(凝析油或石油)，并减少温室气体(甲烷和二氧化碳)排放。循环溶剂注入(CSI)过程，通常被称为吞吐，以二氧化碳/贫气为“溶剂”，是一种潜在的有吸引力的温室气体封存/液体回收联合优化机制，因为与全驱(专用注入和生产井)方案不同，不需要在专门设施、现场管道和油井转换方面的大笔支出。尽管有这些优势，但行业需要关键数据、评估方法和支持模拟研究，以决定是否投资资本在其运营的油井/油田中试验CSI流程。目前的研究计划旨在满足这些需求，同时促进我们对艾伯塔省富含液体的非常规储层的了解。这项研究的重点是使用先进的岩心/岩屑分析和现场数据分析方法，以及成分油藏模拟，以：1)评估LRS中溶剂储存和运输的基本控制；2)使用数值模拟为评估CSI提供关键数据；3)为CSI提供共同优化温室气体封存和烃类液体回收的优化设计建议；4)量化增量石油/凝析油采收率和温室气体捕获潜力。杜维奈页岩将成为研究的重点。

Hydrocarbon liquid-rich shale (LRS) plays are currently the hottest unconventional reservoir targets in North America. In Alberta, liquid-rich areas of the Montney low-permeability siltstone and Duvernay shale are of great interest to the Canadian oil industry, but development has focused on primary depletion with multi-fractured horizontal wells (MFHWs), and hydrocarbon liquid recovery is projected to be low. Further, the current recovery process is inefficient, and does not offer a solution to reducing Alberta's greenhouse gas (GHG) emissions. A potential solution is to inject CO2, or reinject lean gas (rich in CH4) recovered from the reservoir, or a combination of both, back into MFHWs for the simultaneous purpose of increasing liquid hydrocarbon recovery (condensate or oil), and reducing GHG (methane and CO2) emissions. The cyclic solvent injection (CSI) process, commonly referred to as huff'n'puff, with CO2/lean gas as the "solvent", is a potentially attractive mechanism for co-optimization of GHG sequestration/liquid recovery because, unlike full flood (dedicated injection and producing wells) scenarios, large expenditures on specialized facilities, in-field pipelines and well conversions are unnecessary. Despite these advantages, industry requires critical data, evaluation methods, and supporting simulation studies in order to make a decision on whether to invest capital in piloting the CSI process in their operated wells/fields. The current research program is designed to meet these needs, while advancing our understanding of Alberta's liquid-rich unconventional reservoirs. This research proposal focuses on the use of advanced core/cuttings analysis and field data analysis methods, and compositional reservoir simulation, to: 1) evaluate the fundamental controls on solvent storage and transport in LRS; 2) provide critical data for evaluating CSI using numerical simulation; 3) provide optimal design recommendations for CSI that co-optimizes GHG sequestration and hydrocarbon liquid recovery; 4) quantify incremental oil/condensate recovery and GHG capture potential. The Duvernay shale will be the focus of study.