低渗透油藏有效注入水水质界限  

Quality limit of effective injection water in low permeability reservoirs

作　　者：熊生春[1] 储莎莎 赵国梅 何英[1] 窦景平 

机构地区：[1]中国石油勘探开发研究院廊坊分院,河北廊坊065007 [2]中国石油青海油田分公司,甘肃敦煌736202

出　　处：《油气地质与采收率》2015年第3期100-105,共6页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"特低渗油藏有效开发技术"(2011ZX05013-006);中国石油科技攻关项目"柴达木盆地难采储量有效动用技术攻关研究"(2011E-0307)

摘　　要：注水是低渗透油藏补充地层能量的主要方式,而注入水水质是影响注水开发效果的关键因素。在低渗透油藏注入水水质推荐指标中没有注入水矿化度的相关指标,且对渗透率低于10×10-3μm2的储层没有进一步的划分。通过恒速压汞实验,分析喉道分布差异及主流喉道对渗透率贡献程度,剖析不同渗透率级别储层影响注水效果的关键喉道区间;通过室内岩心水驱物理模拟实验,定量分析粘土微粒运移与水化膨胀对渗流能力的影响程度,结合喉道分布特征,初步提出了低渗透油藏不同渗透率储层注入水矿化度、颗粒粒径和颗粒浓度的水质界限。研究结果表明,岩心渗透率越低,注入水矿化度越接近地层水矿化度;岩心渗透率越低,注入水颗粒粒径越大,对储层渗流能力伤害越大;岩心渗透率越低,注入水颗粒质量浓度越高,对储层渗流能力伤害越大。Injection water is the main way to supply formation energy in the low permeability reservoirs,and water quality is the key influencing factor of water flooding effect. Related salinity index of the injection water was not proposed by the recommended specification of the injection water quality using in the low permeability reservoir. There are no standards for dividing the reservoir with permeability less than 10×10-3μm2. The throat distribution difference and the contribution of the dominant throat to the permeability were analyzed through constant velocity mercury injection experiment,and the key throat intervals influencing injection water effect in different permeability reservoirs were obtained. The effects of clay particle migration and hydration expansion on seepage capacity were analyzed quantitatively. The limits of water salinity,particle size and particle concentration with different permeabilities in the low permeability reservoir were initially proposed by laboratory core physical simulation of water flood combined with throat distribution. The results show that if core permeability is lower,the injection water salinity is closer to the formation water salinity;the damaged degree on reservoir seepage capacity is deeper with larger particle size or higher water particle concentration.

关 键 词：低渗透油藏 注入水水质界限 喉道半径 粘土矿物 颗粒粒径 颗粒质量浓度 

分 类 号：TE348[石油与天然气工程—油气田开发工程]