页岩油注CO2过程中重有机质沉积预测
Heavy organic matter deposition prediction for shale oil reservoirs during CO2 injection
赵凤兰 1王鹏 2黄世军1
作者信息
- 1. 中国石油大学(北京)石油工程教育部重点实验室,北京 102249;中国石油大学(北京)石油工程学院,北京 102249
- 2. 中国石化石油勘探开发研究院,北京 102206
- 折叠
摘要
综合考虑页岩基质纳米孔隙中吸附引发的限域效应、毛管压力作用及极性分子间的缔合作用,建立页岩油重有机质沉积预测模型及求解方法,并选取典型区块页岩油样开展重有机质沉积预测,对比分析页岩油重有机质沉积相边界的变化规律及CO2 注入对重有机质沉积相边界的影响.结果表明:缔合作用加剧低温区间的重有机质沉积风险,而高压区间内的重有机质沉积现象受纳米限域效应的影响更加显著;考虑耦合效应时,典型油样在CO2 注入量(摩尔分数)仅为 5%时的重有机质沉积压力上限可达 26.57 MPa,相比于未注气的情况下提高 3 MPa;页岩油注CO2 过程中的重有机质沉积风险最大,控制CO2 注入量和避免地层压力降低过快是潜在的规避重有机质沉积风险的有效手段.
Abstract
Comprehensively considering the adsorption-induced confinement effect in shale matrix nanopores,the capillary pressure effect,and the association effect between polar molecules,a prediction model and solution method of heavy organic matter deposition in shale oil reservoirs was established.The shale oil samples from typical blocks were selected to predict the heavy organic matter deposition,analyze the change of phase boundary for heavy organic matter deposition and the influence of CO2 injection on phase boundary.It is found that the association effect aggravates the risk of heavy organic matter deposi-tion in the low-temperature range,while the nano-confinement effect significantly affects the heavy organic matter deposition phenomenon in the high-pressure range.Considering the coupling effect,the upper limit of heavy can reach 26.57 MPa when the CO2 injection amount is only 5%(mole fraction),which is 3 MPa higher than that without gas injection.The risk of heavy organic matter deposition is the highest during CO2 injection in shale oil reservoirs.Controlling the amount of CO2 in-jection and avoiding a sharp pressure drop are potentially effective means to avoid the risk of heavy organic matter deposition.
关键词
页岩油/CO2注入/重有机质沉积/预测方法Key words
shale oil/CO2 injection/heavy organic matter deposition/prediction method引用本文复制引用
基金项目
国家自然科学基金面上项目(52174039)
国家自然科学基金面上项目(51974328)
中国石油科技项目(ZLZX2020-02-04-04)
出版年
2024
国家科技期刊平台
NSTL
万方数据