准噶尔盆地莫西庄地区下侏罗统储层性质

准噶尔盆地莫西庄地区侏罗系储层具有低成分成熟度、富含岩屑、低杂基含量和高结构成熟度的岩石学特征。孔隙类型主要有残余粒间孔、溶扩粒间孔、粒内溶孔、晶间孔和微裂隙等,其中又以前两种为主,含量分别为25%和56%。通过对压汞测试结果和铸体薄片的物性资料统计分析,笔者认为莫西庄地区砂岩储集性能主要受沉积物粒度、沉积相类型、成岩作用及埋藏条件的控制。其中,埋藏条件是本区保持好储集性能的基础,成岩作用对储集性能起着直接的控制作用,沉积物粒度和沉积相类型对储层的影响是首要的。资料分析均表明,三工河组二段下亚段是本区的优质储层层段,八道湾组储集性能相较较差。

Reservoir quality of the Jurassic strata in the Moxizhuang region,Junggar Basin,Xinjiang

The Jurassic reservoirs in the Moxizhuang region, Junggar Basin, Xinjiang are characterized by low compositional maturity, abundant debris, low matrix contents and high textural maturity. The pore space types include residual intergranular pores, intergranular solution openings, intragranular solution openings, intercrystal pores and microfissures, of which the former two are main types accounting for 25% and 56%, respectively. According to mercury-injection curves and physical properties of cast sections, the reservoir quality of the sandstones in the Moxizhuang region is mostly constrained by sediment grain sizes, sedimentary facies types, diagenesis and burial conditions. The burial conditions are considered as a basis for the good reservoir quality; diagenesis as a direct control on the reservoir quality, and sediment grain sizes and sedimentary facies types as the most important factors influencing the reservoir quality. The reservoir quality is excellent in the lower submember of the second member of the Sangonghe Formation while worst in the Badaowan Formation.