基于页岩油水两相渗流特性的油井产能模拟研究

2023年 51卷 第5期
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Numerical Simulation of Shale Oil Well Productivity Based on Shale Oil-Water Two-Phase Flow Characteristics
孙鑫 刘礼军 侯树刚 戴彩丽 杜焕福 王春伟
SUN Xin LIU Lijun HOU Shugang DAI Caili DU Huanfu WANG Chunwei
中石化经纬有限公司地质测控技术研究院, 山东青岛 266003 中国石油大学(华东)石油工程学院, 山东青岛 266580 成都理工大学能源学院, 四川成都 610059
Geosteering & Logging Research Institute, Sinopec Matrix Corporation, Qingdao, Shandong, 266003, China School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, Shandong, 266580, China College of Energy, Chengdu University of Technology, Chengdu, Sichuan, 610059, China
页岩孔隙结构及固液相互作用复杂,其微观渗流特性加大了页岩油产能预测的难度。为准确评价体积压裂后多尺度孔隙结构发育的页岩油藏产能,基于页岩储层油水两相相渗计算方法和嵌入式离散裂缝模型,考虑页岩真实孔隙结构作用下的微观油水两相渗流特性,形成了考虑页岩体积压裂页岩油藏产能的数值模拟方法。基于页岩储层孔径分布计算油水相渗曲线,结合页岩油藏压裂/生产流程,开展了页岩油藏压裂液空间分布以及油井产能评价模拟分析。结果表明,不同孔径分布下的页岩油水两相相渗曲线存在差异,压裂液主要分布在压裂裂缝、与其相连的天然裂缝以及其周边基质中,在闷井过程中裂缝内压裂液逐渐渗吸进入基质并置换基质中原油,经体积压裂可实现改造区域的整体动用。研究结果可以从微观油水两相渗流特性与宏观产能评价角度为页岩油藏高效开发提供技术支撑。
The pore structure of shale is complex, and solid-liquid interaction occurs. In addition, its microscopic flow characteristics increase the difficulty of shale oil productivity prediction. In order to accurately evaluate the productivity of shale oil reservoirs with multi-scale pore structures after volume fracturing, the microscopic multi-phase flow characteristics under the action of real pore structure of shale were considered based on the oil-water two-phase relative permeability calculation method and embedded discrete fracture model (EDFM) of shale reservoirs. As a result, a numerical simulation method for shale oil reservoir productivity considering shale volume fracturing was developed. The oil-water two-phase relative permeability curve was calculated based on the pore size distribution of shale reservoirs, and combined with the fracturing/production process of shale reservoirs, the spatial distribution of fracturing fluid in shale oil reservoirs and the productivity evaluation of oil well were simulated and analyzed. The results show that there are differences in the oil-water two-phase relative permeability curves of shale under different pore size distributions. Fracturing fluids are mainly distributed in fracturing fractures, natural fractures connected with them, and the surrounding matrix. During the process of shut-in, the fracturing fluid in the fracture is gradually imbibed into the matrix, displacing the crude oil in the matrix and realizing the whole utilization of the stimulated area by volume fracturing. The research results can provide technical support for the efficient development of shale oil reservoirs from the perspective of microscopic oil-water two-phase flow characteristics and macroscopic productivity evaluation.
页岩油藏; 水力压裂; 油水相渗; 压裂液分布; 油井产能; 数值模拟;
shale oil reservoir; hydraulic fracturing; oil-water relative permeability; distribution of fracturing fluid; well productivity; numerical simulation;
四川省自然科学基金项目“基于流固耦合数值模拟的陆相页岩凝析气藏合理开发方式探索”(编号:2022NSFSC1077)、青岛市博士后项目“东营凹陷页岩油测录井产能预测方法研究”(编号:QDBSH20220201023)、中石化经纬有限公司博士后研究项目“东营凹陷页岩油测录井产能预测方法研究”(编号:JWBH2203)联合资助
https://doi.org/10.11911/syztjs.2023084