润湿性及其演变对油藏采收率的影响  

Effects of wettability and its evolution on oil reservoir recovery

作　　者：彭珏[1] 康毅力[1] 

机构地区：[1]西南石油大学"油气藏地质及开发工程"国家重点实验室油井完井技术中心,四川成都610500

出　　处：《油气地质与采收率》2008年第1期72-76,共5页Petroleum Geology and Recovery Efficiency

基　　金：中国石油天然气股份有限公司科技风险创新研究项目"致密砂岩气藏多尺度水相圈闭损害模型与调控研究";四川省杰出青年学科带头人培养基金项目"致密砂岩气藏经济开发全过程储层保护理论及关键技术(07ZQ026-113)"

摘　　要：润湿性是油藏岩石、原油和水三者相互作用的综合表现形式。了解油藏润湿性及其演变过程对提高原油采收率有重要意义,文章综述了成藏前后润湿性的变化特征及其控制因素。原油运移进入储层后,原油中的表面活性组分可能引起油藏润湿性的改变,而水膜不稳定破裂是引起润湿性改变的关键环节。对水膜稳定的热力学条件分析表明,只有当水膜厚度及影响水膜稳定的变量的值在一定范围内,水膜才可能稳定,所以在实际油藏条件下,水膜的稳定性被破坏时,矿物与原油作用将使油藏最终润湿性偏离成藏之前的水润湿状态。水驱及化学驱对润湿性敏感程度的分析表明,可依据不同开采方式所对应的最有利润湿性类型,通过物理或化学方法改变油藏润湿性,提高原油采收率。Wettability is the integrated manifestation of the rock/crude oil/brine interaction.It has important significance for enhancing oil recovery to recognize the reservoir wettability and its evolution process.This paper summarized the behavior and controlling factors of the wettability before and after the oil reservoir is formed.Reservoir rocks are water-wet initially,but the wettability may changes with the surface-active components within crude oil after the oil has migrated into the reservoirs.Unstable blowup of the brine film is the key link of wettability alteration.On the basis of the analysis concerning the thermodynamics of the brine film's stability,it is concluded that a stable brine film can be found only with a restricted range for the thickness of the brine film and the variables which affect the film stability.So under a real reservoir condition,once the stability of the brine film is broken,the interaction between rock and crude oil would make the ultimate reservoir wettability deviate from the water wet state in initial stage of reservoir forming.The sensitivity of the process of water flooding and chemical flooding to wettability has showed that we can change reservoir wettability by physical or chemical means,and thus enhance the oil recovery based on the corresponding favorable wettability type for different production ways.

关 键 词：油藏 润湿性 水膜 热力学 采收率 水驱 化学驱 

分 类 号：TE357[石油与天然气工程—油气田开发工程]