论文详情
摘要:鄂尔多斯盆地陇东西部地区长8组地层是典型的致密砂岩储层,孔隙度和渗透率低,孔隙流体对测井响应的敏感性不强,油层和水层的电阻率对比度低,影响了测井流体识别和测井解释评价。为此,从研究区低阻油层的微观和宏观影响因素出发,探索并建立了双视地层水电阻率差异交会图版法、物性与阵列感应电阻率差异交会图版法以及全烃录井测井联合交会图版法,并利用图版符合率和投票策略构建了一种综合流体识别方法。应用结果表明,造成研究区低阻油层的主要微观因素是高束缚水饱和度和高地层水矿化度,宏观上主要与上覆长7组烃源岩的排烃能力差异有关。综合流体识别法相比于单一流体识别方法,流体识别精度更高,对30口探井的流体识别符合率为83.3%,表明了综合流体识别方法对低阻油层识别的有效性,具有推广和应用价值。
The Chang 8 Formation in the Longdong area of the Ordos Basin is a typical tight sandstone reservoir with low porosity and permeability.The sensitivity of pore fluid to logging response is weak,and the resistivity contrast of oil and water layers is low.Based on micro and macro influencing factors of low-resistivity pays in the study area,the fluid identification accuracies of dual formation water resistivity difference cross plot,physical property and array induced resistivity differential cross plot,and joint hydrocarbon logging cross plot methods were compared.In addition,based on the coincidence rate of the cross plots and voting strategy,a comprehensive fluid identification method was developed.The results showed that a high irreducible water saturation and high salinity of the formation water were the main micro factors of low-resistivity pays.The macro factors were mainly related to regional differences in the hydrocarbon expulsion ability of the Chang 7 source rock.Compared with the individual fluid identification methods,the comprehensive fluid identification method had a higher fluid identification accuracy,and the coincidence rate of fluid identification for 30 exploration wells was 83.3%,indicating that the comprehensive fluid identification method is effective at identifying low-resistivity pays,and it is worthy of promotion and application in other similar areas.
国家自然科学基金(41774144)、国家科技重大专项配套项目(2016ZX05050)和安徽理工大学学校引进人才基金(13200427)共同资助。