基于数字岩心实验对低渗油藏数值模拟的改进  

Improvement of numerical simulation of low-permeabilityreservoirs based on digital core experiments

作　　者：孙胜新 张乔良 王刘英 李凤颖 舒杰 SUN Shengxin;ZHANG Qiaoliang;WANG Liuying;LI Fengying;SHU Jie(Zhanjiang Branch of CNOOC(China)Co.,Ltd.,Zhanjiang Guangdong 524000,China;Shenzhen Branch of CNOOC(China)Co.,Ltd.,Shenzhen Guangdong 518000,China;Hainan Branch of CNOOC(China)Co.,Ltd.,Haikou Hainan 570100,China)

机构地区：[1]中海石油(中国)有限公司湛江分公司,广东湛江524000 [2]中海石油(中国)有限公司深圳分公司,广东深圳518000 [3]中海石油(中国)有限公司海南分公司,海南海口570100

出　　处：《石油化工应用》2024年第11期24-29,共6页Petrochemical Industry Application

基　　金：中海石油(中国)有限公司综合科研项目(KJZH-2024-2207)。

摘　　要：为了提高涠洲A油田低渗油藏剩余油数值模拟预测精度,本文基于数字岩心实验数据对低渗油藏相渗关系式作了深入研究,并对数值模拟软件进行改进,形成了考虑非线性渗流规律的剩余油预测方法。结果表明:在非线性渗流阶段,油水相对渗透率是随着含水饱和度以及驱替压力梯度变化的函数,离注采井井点越远,驱替压力梯度越低,相渗关系式中残余油饱和度越大;涠洲油田在低渗油藏排驱中值压力明显升高,说明非线性渗流特征主要适用于低渗油藏;总结了数值模拟预测不同井网下低渗油藏剩余油分布特征,即在注采井主渗通道上,驱替压力梯度较高,剩余油不富集,远离主渗通道,驱替压力梯度逐渐降低,是主要的剩余油富集区。该方法具有阶段性,解决了传统方法未考虑低渗油藏非线性渗流特征而导致的剩余油预测精度较低的问题,为开展低渗油藏调整挖潜、提高采收率提供重要基础。In order to improve the accuracy of numerical simulation in Weizhou A low-permeability reservoirs,this paper conducted in-depth research on oil-water relative permeability relationship of low-permeability reservoirs based on digital core experiment,improved the numerical simulation software,and formed a remaining oil prediction method considering nonlinear seepage laws.The results show,in the nonlinear seepage stage,the oil-water relative permeability is a function of water saturation and displacement pressure gradient.The farther away from the injection and production well,the lower the displacement pressure gradient,and the greater the residual oil saturation in the relative permeability relationship.The median pressure of oil reservoirs in the Weizhou area has significantly increased in low-per-meability reservoirs, indicating that nonlinear flow characteristics are mainly existing in low-permeability reservoirs. Summarize the distribution laws of remaining oil in low-permeability reservoirs under different well networks predicted by numerical simulation, that is, on the main permeability channel of injection and production wells, the displacement pressure gradient is high, the remaining oil is not enriched, and away from the main permeability channel, the displacement pressure gradient gradually decreases, which is the main area of remaining oil enrichment. This method is phased and solves the problem of low remaining oil prediction accuracy caused by traditional methods not considering the nonlinear flow characteristics of low-permeability reservoirs. It provides an important foundation for improving recovery in low-permeability reservoirs.

关 键 词：低渗 数字岩心 非线性渗流 数值模拟 

分 类 号：TE312[石油与天然气工程—油气田开发工程]