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?

富烃液页岩（LRS）区块是目前北美最热门的非常规油气藏目标。 在阿尔伯塔，Montney低渗透粉砂岩和Duvernay页岩的富液区对加拿大石油工业具有极大的兴趣，但开发集中在多裂缝水平威尔斯（MHFW）的一次枯竭上，预计烃类液体采收率较低。 此外，当前的回收过程效率低下，并且没有提供减少阿尔伯塔的温室气体（GHG）排放的解决方案。 一个潜在的解决方案是将CO2注入或将从储层中回收的贫气（富含CH 4）再注入MFH Ws，或两者结合，以同时提高液态烃回收（凝析油或石油）和减少GHG（甲烷和CO2）排放。 循环溶剂注入（CSI）工艺，通常称为吞吐，以CO2/贫气作为“溶剂”，是一种潜在的有吸引力的温室气体封存/液体回收共同优化机制，因为与全驱（专用注入和生产威尔斯井）方案不同，不需要在专用设施、现场管道和油井转换上的大量支出。 尽管有这些优势，行业仍需要关键数据、评估方法和支持模拟研究，以便决定是否投资资本在其运营的威尔斯/油田中试点CSI工艺。 目前的研究计划旨在满足这些需求，同时提高我们对阿尔伯塔富液非常规油藏的认识。 该研究方案侧重于使用先进的岩心/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提供最佳设计建议，共同优化GHG封存和烃类液体回收; 4）量化石油/凝析油开采增量和温室气体捕获潜力。 Duvernay页岩将是研究的重点。

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.