摘要
为改善低渗油藏高含水期水驱开发效果,在室内应用计算机断层扫描(computed tomography,CT)技术开展了岩心深部调剖驱替实验研究,获得了不同时刻岩心内油水分布状态信息,探索了深部调剖驱油机理。实验结果表明,一次水驱过程,注入水主要在高渗层内以活塞式向岩心深部推进,形成水驱优势通道,引起无效水循环;低渗层内水驱波及体积较小,仅波及到岩心第27个切片处。后续水驱过程,改性淀粉凝胶保持很好的完整性并有效封堵高渗层,注入水不仅启动了凝胶正上部的低渗层剩余油区域而且扩大了岩心入口端低渗层波及体积。高渗层采收率首先受驱替效率和波及效率共同影响,当波及效率不在增加,采收率的大小取决于驱替效率的大小;低渗层采收率一直受驱替效率和波及效率共同影响,且波及效率发挥主要作用。后续水驱过程低渗层起主导作用,采收率增加了15.1%。
The experimental study of profile control and displacement in depth was carried out by using computed tomography(CT)scanning technology,in order to improve the development effect of water drive in high water cut stage of low permeability reservoir.The information of oil-water distribution in core at different time was obtained,and the mechanism of deep profile control and oil displacement was explored.The results show that the injected water is mainly pushed to the deep core by piston in the high permeability layer in the process of primary water drive.The dominant channel of water drive is formed,and invalid water cycle is formed.The sweep efficiency of low permeability layer is relatively small,only spreading to the 27th section of core.During the subsequent water flooding process,the modified starch gel maintains good integrity and effectively blocks the high permeability layer.The injected water not only starts the remaining oil area of the low permeability layer in the upper part of the gel,but also expands the sweep volume of the low permeability layer at the inlet end of the core.The oil recovery of high permeability layer is first affected by displacement efficiency and sweep efficiency.When sweep efficiency is not increasing,the recovery depends on displacement efficiency.The oil recovery of low permeability layer is always affected by displacement efficiency and sweep efficiency,and sweep efficiency plays a major role.The low permeability layer plays a leading role in the subsequent water drive process,and the recovery factor increases by 15.1%.
作者
侯思伟
王毅
饶政
张春光
HOU Si-wei;WANG Yi;RAO Zheng;ZHANG Chun-guang(Shixi Oilfield Operation Area, Xinjiang Oilfield Company, Karamay 834000, China)
出处
《科学技术与工程》
北大核心
2020年第32期13163-13167,共5页
Science Technology and Engineering
基金
国家科技重大专项(2016ZX05010-005)。
关键词
改性淀粉凝胶
深部调剖
波及效率
驱替效率
室内实验
modified starch gel
deep profile control
sweep efficiency
displacement efficiency
laboratory experiment
