曲9-21块沙三段储层注入水与储层配伍性研究

Study on Compatibility between Injecting Water and Reservoir of the Third Member of Shahejie Formation in Block-Qu 9-21

为了考察曲9-21块沙三段储层注水的可行性,进行了储层物性特征研究、水源水和地层水静态配伍性研究、储层敏感性实验研究及水源水与储层的动态配伍性实验研究。同时还对注水过程中的伤害机理进行分析,并制定了相应的注水水质指标。室内动、静态实验研究认为,水源水矿化度高于地层水矿化度及水源水中机械杂质是影响注水开发的重要因素,未经处理的现场水源水长期注入储层对储层岩心造成了较大的伤害,岩心渗透率保留率仅为29.4%,因此减少水源水中的机械杂质含量是降低储层伤害的主要措施。为了尽量减少机械杂质对储层的伤害,曲9-21块沙三段注水水源的机械杂质指标推荐为B2级。

in order to evaluate the feasibility of water flooding for the 3rd member of Shahejie formation in block-Qu 9-21, a series of concerned experiments were carried out, such as reservoir petrophysical properties analysis, static compatibility evaluation between source water and formation water, formation sensitivity analysis and dynamic compatibility evaluation between source water and formation. In addition, the damage mechanism of water flooding process was analyzed and the quality index of the injected water was established by means of laboratory water flooding tests. It was shown that permeability retention rate was low to 29.4% when core had been more seriously damaged from water flooding of long duration by untreated field source water. It was concluded that the higher salinity of the injected water than formation water and the mechanical impurities of the injected water were key factors influencing water flooding development. Hence, in order to remove formation damage, the reduction of the content of mechanical impurities of the injected water was a major measure taken. According to test results, the recommended mechanical impurities index of the injected water for the third member of Shabejie formation in block-Qu 9-21 is grade B2.