哈得4东河砂岩油藏注水水质标准研究

On Water Quality Standard for Flooding Donghe Sandstone Reservoir in HD-4 Oil Field

塔里木哈得4东河砂岩油藏将由注矿化度25 g/L的地表水(清水)转为注矿化度240 g/L的采油污水。清水与污水配伍性差,应分注,注清水时需采取防垢措施。实验考察了与注入水腐蚀性、地层伤害性有关的诸因素,推荐了清水和污水水质控制指标。要将A3钢在清水和污水中的腐蚀率控制在0.076 mm/a以内,溶解氧浓度均应小于0.89 mg/L(尽管污水对溶解氧的耐受性强),TGBI、B、SRB菌数应分别小于103、102、102个/mL。根据储层岩心注模拟水伤害实验结果并考虑油田生产情况,为了使储层岩心渗透率的伤害率低于15%,注入水(清水、污水)中悬浮物粒径应控制在5μm以下,悬浮物含量小于7.5 mg/L,TGBI、B、SRB菌数应分别小于104、103、102个/mL,Fe3+浓度应小于2 mg/L,含油量应小于10 mg/L。图11参6。

The Donghe sandstone oil reservoir in HD-4 oil field, Tarim, is flooded preliminarily with a surface water （SW） of TSD = 25 g/L and the recycled produced water （PW） of TSD = 240 mg/L is to be used for this purpose. The SW and the PW are poorly compatible and should be used separately and some antiscaling measure should be taken when using the SW. The factors involved in water corrosivity and in formation damage by flooding waters are investigated experimentally and the relevant norms for the SW and the PW as reservoir flooding waters are suggested. To reduce the corrosion rate of A3 steel below 0.076 mm/a, the content of dissolved O2 in SW and PW should be 〈 0.87 mg/L （in spite of higher tolerancy of the PW to dissolved 02）, the population of bacteria TGB, IB, and SRB in the two waters---〈 10^3, 〈 10^2, and 〈 10^2 cell/mL, respectively. According to the results of experiments on reservoir core permeability damage caused by simulation waters and taking into account field operation ability, following technical norms are recommended for the reservoir flooding waters （SW and PW） ： particle size of suspended solids 〈 5μm; cotent of suspended solids 〈7.5 mg/L; population of bacteria TGB, IB, and SRB 〈10^4, 〈10^3, and 〈10^2 cell/mL, respectively; Fe^3＋ concentration 〈2 mg/L; content of oily substances 〈 10 mg/L.