页岩岩心样品烃类散失特征与地质意义

Evaluation of evaporative loss of hydrocarbon in shale samples and its geological implications

钱门辉 黎茂稳 蒋启贵 李志明 陶国亮 鲍云杰

QIAN Menhui LI Maowen JIANG Qigui LI Zhiming TAO Guoliang BAO Yunjie

中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126 页岩油气富集机理与有效开发国家重点实验室, 江苏 无锡 214126 国家能源页岩油研发中心, 江苏 无锡 214126 中国石化油气成藏重点实验室, 江苏 无锡 214126

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Wuxi, Jiangsu 214126, China State Energy Center for Shale Oil Research and Development, Wuxi, Jiangsu 214126, China SINOPEC Key Laboratory of Petroleum Accumulation Mechanisms, Wuxi, Jiangsu 214126, China

游离烃含量是页岩油资源评价中最关键参数之一，但由于烃类散失的影响，实验测得的游离烃含量往往与真实含量差异较大，从而导致含油性评价结果“失真”。为研究含油泥页岩烃类散失过程，获取烃类散失量及校正系数，本文利用成熟度相近、不同岩相的新鲜含油岩心样品，对不同放置时间后样品的烃类残留量及残留组分开展实验并进行综合分析。研究认为，页岩样品烃类散失分早期快速散失和后期缓慢散失2个过程，挥发组分主要为C13—C15以前的低碳数烃类，中质—重质组分受影响较小；储集物性条件及原始含油量共同控制了烃类散失量及散失过程。原始含油量越高、储集物性越好的泥页岩样品烃类散失量越大，因此，在评价储集物性好的高含油的页岩油“甜点”段时，更需要注意原始烃含量的恢复。

Free hydrocarbon content is one of the key parameters for resource assessment of shale oil.However, due to the evaporative loss of hydrocarbon, the measured results from lab analysis differ greatly from real value, which leads to the "distortion" of shale oil resource assessment.To investigate the process of the evaporative loss and obtain the hydrocarbon loss amount and correction coefficient, a time-series of analysis has been carried out on fresh oil-bearing shale samples with similar maturity and different lithofacies for both the amount and the composition of the hydrocarbons retained in shale.Results suggest that there are two processes of early rapid and later slow evaporative loss. The volatile components are mainly light hydrocarbons with carbon numbers smaller than C13-C15, while the medium to heavy components are less affected. Both the amount and processes of hydrocarbon evaporative loss are controlled by the physical properties and original oil content of shale samples.The oil-bearing shale samples with higher original oil content and better physical properties appear to have more evaporative loss of hydrocarbons.Results also indicate that more attention should be exercised on original hydrocarbon content when conducting the shale oil resource assessment of "sweet spot" section with high oil content and good physical properties.

国家自然科学基金项目"陆相富有机质页岩成烃动态演化与烃类赋存机理" 42090022

https://doi.org/10.11781/sysydz202203497