海上W油田注水损害因素分析及水质指标研究

Analysis of Damage Factors of Water Injection and Water Quality Index in Offshore W Oilfield

在分析海上W油田注水损害因素的基础上,室内以注入水的悬浮固体粒径(d)、悬浮固体浓度(SS)和含油量(O)为考察指标,开展了适合W油田的注入水水质指标评价实验。结果表明,随着注入水悬浮固体粒径、悬浮固体浓度以及含油量的增大,低渗岩心和高渗岩心的渗透率损害率均明显升高,且低渗岩心渗透率损害率的增幅明显高于高渗岩心的。针对海上W油田W-1N段低渗储层,其最佳注入水水质指标为d≤2.0μm、SS≤3.0 mg·L^(-1)、O≤8.0 mg·L^(-1);而针对W-1H段高渗储层,其最佳注入水水质指标为d≤4.0μm、SS≤8.0 mg·L^(-1)、O≤15.0 mg·L^(-1)。

Taking the suspended solid particle size(d),suspended solid concentration(SS),and oil content(O)as investigation indexes,we carried out evaluation experiments of injection water quality index suitable for W Oilfield on the basis of the analyses of the damage factors of water injection in offshore W Oilfield.The results show that the permeability damage rates of low permeability core and high permeability core increase obviously with the increase of d,SS,and O,and the increase of permeability damage rate of low permeability core is obviously higher than that of high permeability core.For the low permeability reservoir in W-1N section of offshore W Oilfield,the optimal injection water quality indexes are determined as follows:d≤2.0μm,SS≤3.0 mg·L^(-1),and O≤8.0 mg·L^(-1).For the high permeability reservoir in W-1H section,the optimal injection water quality indexes are determined as follows:d≤4.0μm,SS≤8.0 mg·L^(-1),and O≤15.0 mg·L^(-1).