基于CT扫描的低渗透岩心油水相对渗透率曲线计算研究  

Calculation of oil-water relative permeability curves of low permeability cores based on CT scanning

作　　者：吴阳 刘天乐[1] 任建飞 胡晨 莫邵元 焦春艳[3,4] WU Yang;LIU Tianle;REN Jianfei;HU Chen;MO Shaoyuan;JIAO Chunyan(Engineering Research Center of Rock-soil Drilling&Excavation and Protection,Ministry of Education,China University of Geosciences(Wuhan),Wuhan Hubei 430074,China;PetroChina Shenzhen New Energy Research Institute Co.,Ltd.,Shenzhen Guangdong 518052,China;Research Institute of Petroleum Exploration and Development,Beijing 100083,China;Key Laboratory of Natural Gas Accumulation and Development,CNPC,Langfang Hebei 065007,China)

机构地区：[1]中国地质大学(武汉)岩土钻掘与防护教育部工程研究中心,湖北武汉430074 [2]中石油深圳新能源研究院有限公司,广东深圳518052 [3]中国石油勘探开发研究院,北京100083 [4]中国石油天然气集团公司天然气成藏与开发重点实验室,河北廊坊065007

出　　处：《钻探工程》2025年第2期98-105,共8页Drilling Engineering

基　　金：教育部岩土钻掘与保护工程研究中心开放基金(编号:202406)。

摘　　要：低渗透油藏油水相对渗透率是表征低渗透油藏注水开发效果的关键参数。由于低渗透油藏孔隙狭小、渗流阻力大,油水两相渗流过程中,岩心“末端效应”导致计算的油水相对渗透率曲线与实际结果不一致,影响低渗透油藏注水开发方案制定。为避免岩心“末端效应”对低渗透油藏油水相对渗透率影响,应用CT扫描技术在线获得不同时刻低渗透岩心内含水饱和度的沿程分布信息。根据油水相对渗透率曲线经验公式,结合低渗透油藏油水渗流模型和模拟退火优化理论得到了油水相对渗透率曲线优化参数,从而得到油水相对渗透率。计算结果表明:CT试验是监测岩心含水饱和度特征的一种非常有效的试验手段,避免了“末端效应”对含水饱和度特征的影响;通过模拟退火方法可以得到全局最优相对渗透率曲线,含水饱和度、岩心两端压差测试结果与计算拟合结果吻合度较高,相对误差小于8%。研究方法可以快速、准确地计算低渗透油藏油水相对渗透率曲线,为低渗透油藏开发生产提供有力的支持和指导。The oil-water relative permeability is a key parameter to characterize the effect of water injection in low permeability oil reservoirs.Due to the narrow pore size and large seepage resistance of low permeability reservoirs,the“end effect”of core leads to the inconsistency between the calculated oil-water relative permeability curves and the actual results,which affects the establishment of water injection development scheme of low permeability reservoirs.To avoid the influence of core“end effect”on the relative permeability,the CT scanning has been applied to monitor the in-situ water saturation profiles along the low permeability core at different time points.Based on the experience formula of oil-water relative permeability curve,optimal parameters of the relative permeability has been obtained by combining the oil-water flow methods in low permeability reservoirs,and the simulated annealing optimization theory.The results show that CT scanning test is a very effective test method which can not only monitor water saturation profile and water saturation characteristics in the central core,but also avoid the influence of“end effect”.The global optimal relative permeability curve has been obtained with the Simulated Annealing method.The test results of water saturation and the pressure difference at both ends of the core accord with the results of calculation.This method has the advantage of high goodness of fit and satisfactory effect,with the relative permeability less than 8%.This method is proved to be efficient and accurate for calculating oil-water relative permeability curves,providing a strong support and guidance for the development of low permeability reservoirs.

关 键 词：低渗透油藏 CT扫描技术 含水饱和度剖面 岩心“末端效应” 模拟退火 相对渗透率曲线 

分 类 号：TE348[石油与天然气工程—油气田开发工程] P634[天文地球—地质矿产勘探]