吴起油田庙沟马崾岘油区储层特征及敏感性分析

Reservoir characteristics and sensitivity analysis of the Mayaoxian oil region of Miaogou inWuqi oilfield

庙沟马崾岘油区储层类型为低渗透层—超低渗透层储层,通过铸体薄片、粘土X衍射分析、敏感性试验等方法,对储层孔隙类型、孔喉结构、敏感性进行分析,研究区岩石类型主要为石英砂岩和长石砂岩为主,主要孔隙类型为粒间孔和长石溶孔,储层物性较差,延10为低孔低渗储层,长4+5为低孔特低渗储层,长9为特低孔特低渗储层。结合邻区岩芯试验得出,延10储层为中等偏强水敏、强盐敏、强酸敏、弱碱敏;长4+5储层为中等偏弱速敏、水敏、盐敏、酸敏,中等碱敏;长9储层为中等偏弱速敏、水敏、盐敏、酸敏,弱碱敏。延10储层为强酸敏,在后期生产和施工过程中应谨慎选择酸化措施。

The reservoir type in the Mayaoxian oil region of Miaogou is a low permeability to ultra-low permeability reservoir.The pore type,pore throat structure,and sensitivity of the reservoir analyzed by methods such as casting thin sections,clay X-ray diffraction analysis,and sensitivity testing.The results indicate that the rock types are mainly quartz sandstone and feldspar sandstone,and the pore types are intergranular pores and feldspar dissolution pores.The reservoir has poor physical properties,with“Yan 10”being a low porosity and low permeability reservoir,“Chang 4+5”being a low porosity and ultra-low permeability reservoir,and“Chang 9”being an ultra-low porosity and ultra-low permeability reservoir.Based on neighboring rock core tests,it is found that the“Yan 10”reservoir is moderately strong in water sensitivity,strong in salt sensitivity,strong in acid sensitivity,and weak in alkali sensitivity.The“Chang 4+5”reservoir is moderately weak in speed sensitivity,water sensitivity,salt sensitivity,acid sensitivity,and moderate in alkali sensitivity.The“Chang 9”reservoir is moderately weak in speed sensitivity,water sensitivity,salt sensitivity,acid sensitivity,and weak in alkali sensitivity.The“Yan 10”reservoir is strongly acid sensitive,and acidification measures should be carefully selected in the later production and construction process.