Chang81 reservoir in Honghe oilfield is a tight sandstone reservoir with dual porosity consisting of pores and fractures.Due to various interstitial material component ,fine grain size,complex pore structure ,poor physical condition and strong heterogeneity ,effective reservoir characteristics are inconspicuous and production is generally low .In addition , production capacities among wells are significantly different owing to varying degrees of reservoir permeability improve -ment by fractures with different occurrences ,openess and filling degree .Based on core analysis ,experimental test and pro-duction data ,five evaluation index ,including logging facies ,pore throat structure ,physical property ,permeability and frac-ture effectiveness,were selected to evaluate dual-porosity Chang81 reservoir and establish evaluation standards .Verified by 31 wells in Honghe oilfield ,the evaluation results are consistent with production conditions .%鄂尔多斯盆地西南部红河油田延长组长81致密砂岩储集层同时发育孔隙型和裂缝型双重储集空间.孔隙型基质储集层具有填隙物成分复杂、岩石粒度细、孔喉结构复杂、物性差和非均质性强等特性,导致有效储集层特征不明确,储集层产量普遍较低;同时,不同产状、张开度和充填程度的裂缝对基质储集层渗透性改造程度不同,井间产能差异较大.基于岩心分析资料,以测试、生产数据为约束条件,综合运用地质研究和测井手段,选取有利测井相、孔喉结构、储集性、渗透性以及裂缝有效性等五项评价指标对长81双重介质致密砂岩储集层进行有效性综合评价,并建立了评价标准.对研究区域内31口井的分析表明,储集层有效性评价结果与生产情况有良好一致性.
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