摘要
准噶尔盆地玛湖凹陷二叠系风城组碱湖型页岩油资源丰富,是准噶尔盆地非常规油气勘探的重要领域。利用岩心、岩石薄片、X射线衍射、电子探针和扫描电镜等资料,研究了玛湖凹陷二叠系风城组页岩油储层的成岩作用、储集空间特征及其相互关系。结果表明:风城组页岩油储层包括粉砂岩类、泥页岩类、白云岩类等3类岩石;储集空间类型有残余粒间孔、溶蚀孔、晶间孔、泄水缝、层理缝和构造缝;不同类型岩石经受的成岩作用有变化,导致了差异化的储集空间发育特征。认为以微米级残余粒间孔及长石溶孔为主要储集空间的粉砂岩类物性最好,孔隙结构最优,是玛湖凹陷风城组页岩油最重要的“甜点”储层类型。风城组储层中普遍含凝灰质火山物质,火山玻璃的脱玻化与重结晶形成的晶间孔以及构造活动造成的破裂缝在3类岩石中均不同程度地发育,造成研究区页岩油储层常具有孔-缝双重介质特征。
Because of the abundance of the alkaline lake shale oil resources of the Permian Fengcheng Formation in the Mahu Sag of Junggar Basin, it is an important replacement field for unconventional oil and gas exploration in Junggar Basin. The reservoir pore space characteristics, diagenesis and their relationship of the shale oil reservoir of Fengcheng Formation in the Mahu Sag of Junggar Basin are studied by using the data of core, petrographic thin section, X-ray diffraction, electron probe and SEM. The results show that:(1)The shale oil reservoir of Fengcheng Formation develops three types of rocks, including siltstone, shale and dolomite;the pore types of shale oil reservoir include residual intergranular pores, dissolution pores, intercrystalline pores, drainage fractures, bedding fractures and structural fractures.(2)Siltstone is moderately compacted, and feldspar of terrigenous clasts and tuffaceous volcanic clasts are dissolved, and the pore types are dominated by feldspar dissolution pores and micron-scale residual intergranular pores.(3)Dolomite is moderately compacted, and carbonate mineral recrystallization and dissolution are developed. The pore types are dominated by micron-scale residual intergranular pores, intercrystalline pores and dissolution pores.(4)Shale is strongly compacted, and the drainage structure caused by rapid compaction is common. Mineral dissolution is not developed, and the pore types are mainly composed of nanometer-scale residual intergranular pores, semi-filled drainage fractures and bedding fractures.(5)Volcanic materials are generally developed in Fengcheng Formation, and intercrystalline pores formed through the devitrification and recrystallization of volcanic glass are common.(6)The fractures caused by tectonic activities are developed in the three types of rocks, resulting in dual media characteristics of Fengcheng shale oil reservoir in the study area. It is considered that siltstone developed micron-scale residual intergranular pores and feldspar dissolution pores has the be
作者
单祥
何文军
郭华军
邹志文
陈希光
窦洋
彭博
SHAN Xiang;HE Wenjun;GUO Huajun;ZOU Zhiwen;CHEN Xiguang;DOU Yang;PENG Bo
出处
《海相油气地质》
CSCD
北大核心
2022年第3期325-336,共12页
Marine Origin Petroleum Geology
基金
中国石油“十四五”前瞻性基础性重大科技项目“准噶尔盆地全油气系统地质理论与勘探实践”(编号:2021DJ0108)
“深层超深层有效储层形成主控因素与预测技术研究”(编号:2021DJ0202)联合资助。
