鄂尔多斯盆地姬塬油田长8储层敏感性研究

Research on sensitivity of Chang 8 reservoir of Jiyuan Oilfield in Ordos Basin

利用X衍射、全岩定量分析、薄片鉴定、水驱敏感性流动试验等方法,研究鄂尔多斯盆地姬塬油田长8超低渗透砂岩油藏储层敏感性,主要分析了敏感性类型、伤害程度及影响因素。研究结果表明,储层具有弱水敏、酸敏性变化范围大、弱—中等碱敏、弱—中等盐敏、弱—无速敏特征;储层流动敏感性综合评价结果为弱敏感。影响储层敏感性最直接的因素是敏感性矿物的分布,即储层所处的成岩相带决定其敏感性类型及敏感性程度。另外,储层水敏性受物性及孔隙结构的影响,储层物性越差,孔隙结构非均质性越强,储层水敏性越弱。储层所处成岩相带及敏感性的不均一性,使得研究区超低渗透砂岩油藏储层具有大规模开发的可能性。

With the technologies of X-ray diffraction, whole rock quantitative analysis, thin section and flowrate test, the sensitivity of uhra-low permeability sandstone reservoir in Jiyuan Oilfield of Ordos Basin were analyzed. The analysis included the sensitivity type, the degree of rock injury to sensitivity and the influence factors of reservoir sensitivity. The study results show that the reservoir is characterized by weak water sensitivity, wide range of acid sensitivity, weak-middle alkali sensitivity, weak-middle salt sensitivity and weak-non speed sensitivity. As a whole, the sensitivity evaluation results of reservoir flow is the weak sensitivity. The main control factor of reservoir sensitivity is the distribution of sensitive minerals and the diagenetic reservoir facies control the sensitivity type and the degree of rock injury to sensitivity. In addition, the poorer the reservoir physical property is and the stronger the reservoir heterogeneity is, the weaker the reservoir sensitivity is. The heterogeneity of the diagenetie reservoir facies and the reservoir sensitivity make the ultra-low permeability sandstone reservoir in study area be developed on a large scale.