下寺湾油田长8_2超低渗透储层敏感性研究

Study on Sensitivity of Chang 8_2 Ultra-low Permeability Reservoirs in Xiasiwan Oilfield

下寺湾油田长82油藏具有很好的勘探开发潜力,但储层致密,属于特低孔-超低渗级别油藏,容易造成储层伤害。在储层特征的基础上,对长82储层16块岩石样品进行敏感性室内评价试验,得出敏感性伤害程度;并结合扫描电镜、铸体薄片、黏土矿物分析和高压压汞等方法,分析了长82储层的伤害机理。结果表明长82储层具有中等速敏、弱水敏、弱碱敏和强酸敏的特征。研究结果为超前注水和酸化压裂改造等措施提供决策依据。

The Chang 82 reservoir had very good exploration potential with tight property,it was a reservoir with extra-low porosity and super low permeability,it was damaged easily.Based on the study of reservoir characteristics,the formation sensitivity was studied through laboratory test on 16 rock samples.The damage mechanism was established and analyzed through the SEM,casting thin section,clay mineral analysis and high-pressure mercury injection method.The results show that velocity sensitivity is middle,water sensitivity is weak and alkali sensitivity is weak,acid sensitivity is strong in the reservoirs.It provides a basis of decision-making for the reconstruction of acidification fracturing for advanced water injection.