鄂尔多斯盆地姬塬地区黄39罗1井区长8_1低渗透储层孔隙结构特征研究

Research on Characteristics of Pore Structure of Reservoir Chang 81 with Low Permeability in Well-block Luo 1 of Jiyuan Area in Ordos Basin

姬塬地区黄39-罗1井区是长庆油田重点层段开发区,而延长组长81储层具有典型的低孔低渗的特点。应用压汞资料研究该区孔隙结构特征,研究结果表明,研究区储层以原生粒间孔隙、长石溶蚀孔隙为主,岩屑溶蚀孔隙次之;小孔和细孔是该区油气的主要储集空间,而小喉则是该区基本的渗流通道;小喉-中型、小喉-偏小型为该区常见的孔隙结构特征,反映成岩作用强烈,非均质性强,整体物性差,是造成该区油井产能差异的重要因素。

Well-block Luo 1 of Jiyuan Area is an important layer in Changqing Oilfield,The Reservoir Chang 81 is characterized by low pore and low permeability.Mercury injection date can be applied to the reservoir pore structure characterization.The results show that the intergranular pore and feldspar-dissolved pore are predominated,the detritus-dissolved pore takes second place,others pore is rare in the research area.Most reserved space is small pore and fine pore,and small throat is the basic seepage.According to mediam radius of throat,pore structure of Reservoir Chang 81 is divided into four types.Type Ⅱ and Ⅲ reflect poor reservoir properties and strong microscopic heterogeneity in the research area,which leads to difference of oil-well productivity.