鄂尔多斯盆地苏里格气田东部优质储层分布规律

DISTRIBUTION REGULARITY OF HIGH-QUALITY RESERVOIRS IN THE EASTERN SULIGE GAS FIELD,THE ORDOS BASIN

分析优质储层的分布规律及其控制因素,对于加快天然气的勘探开发进程具有十分重要的现实意义。通过岩心观察、铸体薄片鉴定、粒度分析、扫描电镜、毛管压力分析以及包裹体测温等分析测试手段,根据成岩作用和成岩相特征,探讨鄂尔多斯盆地苏里格气田东部优质储层的分布规律。研究表明,碎屑颗粒粒度、砂岩类型以及成岩作用的差异是影响储层物性的主要因素。研究区目的层可划分出9种成岩相带,主要以优质储层与非优质储层的组合形式出现。位于致密相之间的石英加大胶结混合孔隙相、自生高岭石胶结晶间孔相以及粘土杂基混合充填溶蚀相,是发育优质储层的良好成岩相带。微裂缝的发育以及溶解作用的发生,是形成优质储层的关键因素。

It is of practical significance in accelerating the progress of natural gas exploration and development to analyze controlling factors and spatial distribution patterns of high-quality reservoirs. Major controlling parameters of diagenesis and diagenetic facies on spatial distribution patterns of high-quality reservoirs of Upper Paleozoic in the eastern Sulige Gas Field of the Ordos Basin are discussed in this paper, based upon detailed description and observation of drilling cores, accompanied with various analytical and measurements including identification and quantitative statistics of thin sections under microscope, grain size analysis, electron scan microscope （ESM）, capillary pressure analysis and measurement of homogeneous temperature for inclusions. Research shows that detrital grain size, sandstone types and diagenetic differences of sandstones are the main controlling factors for reservoir quality. Nine diagenetic facies can be recognized. The quartz overgrowth cementation mixture pores diagenetic facies, authigenic kaolinite cementation inter-crystal pores diagenetic facies, and clay matrix filling dissolution facies distributed between dense diagenetic facies are the most profitable diagenetic zones for high-quality reservoirs. Micro-fractures and dissolution are the key parameters for high-quality reservoirs formation.