准噶尔盆地腹部深埋储层次生孔隙成因机理研究

准噶尔盆地腹部勘探目的层埋深大，一般在5 500～6 000 m左右，属于深埋储层。在对大量薄片分析鉴定的基础上，运用扫描电镜、阴极发光和X衍射粘土分析等手段，对研究目的层的孔隙类型和成因机理进行了研究。研究发现孔隙类型以次生溶蚀孔隙为主。中晚侏罗世发育的车莫古隆起导致非持续埋藏的成岩背景，由于中途开启地层抬升暴露，酸性大气淡水对粒间方解石胶结物淋滤溶蚀，产生次生溶孔；白垩系之后再度埋藏发生有机酸内幕溶蚀作用。由于地层抬升剥蚀导致成岩阶段滞后，勘探目的层现今处于晚成岩A1亚期是次生孔隙保存的重要条件。

Forming Mechanism of Secondary Pores in Deep Buried Reservoirs of Junggar Basin

The subject reservoir were deep buried reservoir rocks in the larger depth of the hinterland of Junggar Basin,with the depth from 5 500 to 6 000 m.A lot of thin sections were analyzed by standard petrographic microscope,X-ray diffraction,scanning electron microscope coupled energy-dispersive analysis and cathodoluminescence were used to analyze the types and mechanism of secondary pores.The result shows that the secondary pores are main types in deep-buried reservoirs.The Che-Mo ancient uplift was growing in Middle Jurassic.The result was that diagenesis was nonpersistent and the stratum was uplifted.Grain-to-grain calcite cement had dissolution action by acidic atmospheric water and it had a lot of secondary porosity.The stratum was embedded after Cretaceous system and had dissolution action by organic acid.Diagenesis was delayed because the stratum was uplifted.The object reservoir was in A1 of late diagenetic stage that had caused secondary porosity remained.