基于物质的量平衡的气藏CO埋存潜力评估方法

A evaluation method of CO sequestration potential in gas reservoirs based on mole balance

汤勇 刘梦云 秦佳正 汪勇 袁权 李相宏 何佑伟

TANG Yong LIU Mengyun QIN Jiazheng WANG Yong YUAN Quan LI Xianghong HE Youwei

西南石油大学油气藏地质及开发工程国家重点实验室 中国石油西南油气田公司川中油气矿

State Key Laboratory of Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan, China Central Sichuan Oil and Gas District, PetroChina Southwest Oil and Gas Field Company, Suining 629000, Sichuan, China

枯竭气藏是进行CO₂埋存的有利场所之一，进行气藏CO₂埋存潜力评估至关重要。基于气藏生产和CO₂埋存采注过程中物质的量平衡原理，考虑气体偏差系数随着温度和压力的变化，依据气体状态方程，建立了气藏CO₂埋存潜力评估模型，分析了采出程度和气体偏差系数对气藏CO₂埋存量的影响。结果表明，采出程度和气体偏差系数越大，越有利于CO₂埋存。结合川中A区块L1井的实际参数进行了CO₂埋存潜力评估，考虑气体偏差系数随储层温度和压力变化预测的CO₂埋存量比传统物质平衡法计算的埋存量高27%。该方法对CO₂埋存潜力评价研究及埋存方案优化具有重要意义。

Depleted gas reservoirs are one of the favorable sites for underground CO sequestration, and it is vital to evaluate the CO sequestration potential of gas reservoirs. Based on the principle of mole balance in the gas recovery and CO sequestration, production and injection processes, the gas reservoir CO sequestration potential evaluation model was developed, which incorporates the gas state equation and the variation of gas deviation factor with temperature and pressure. With this model, the effects of the gas recovery efficiency and gas deviation factor on the CO sequestration capacity were analyzed. The results show that higher recovery efficiency and gas deviation factor are more favorable for CO sequestration. The CO sequestration potential evaluation for Well L1 in block A, central Sichuan Basin, reveals that the CO sequestration capacity predicted by the presented method considering the variation of gas deviation factor with reservoir temperature and pressure is 27% higher than that estimated by the conventional material balance method. The presented method is valuable for CO sequestration potential evaluation and scheme optimization.

10.13639/j.odpt.2023.02.011