苏里格气田西部山1段储层特征及影响因素

下二叠统山西组1段（简称山1段）是苏里格气田西部地区的主力产气层之一，由于该储层经历了长期的压实、胶结等致密化成岩作用改造，故储集物性较差。为了给该区岩性气藏的储层预测提供依据，从储层岩石学特征、孔隙类型和储层物性特征等方面，研究了山1段碎屑岩储层的特征，剖析了影响该储层储集性能的主控因素。通过对岩心、铸体薄片、扫描电镜及物性分析等资料的分析研究，结果表明：①山1段储层岩石类型主要是岩屑石英砂岩、石英砂岩和岩屑砂岩，孔隙类型以粒间溶蚀孔、粒内溶孔及铸模孔为主，物性较差；②影响砂岩储集性能的主控因素为沉积环境、颗粒性质、填隙物成分和含量、成岩作用改造程度；③相对优质储层多出现在石英含量高的河道粗粒砂体中，其分布受成岩作用及填隙物含量的影响。

Features and influencing factors of reservoirs in the Shan-1 member, west Sulige gas field

The first member of the Lower Permian Shanxi Formation (abbreviated for Shan 1 member) is one of the major pay zones in the western Sulige gas field. Its poroperm characteristics are poor due to long term modification of compaction and cementation. The characteristics and controlling factors on properties of reservoirs in the Shan 1 member clastic rocks were studied in respects of petrologic features, pore types and reservoir physical properties, so as to provide a basis for prediction of the lithologic gas reservoirs in the study area. The following understandings are obtained through analyzing various data such as core, cast thin section, SEM and physical properties. The rock types of Shan 1 member are dominated by lithic quartz sandstone, quartz sandstone, and lithic sandstone and its poroperm characteristics are poor as the pore types are predominantly of intergranular dissolved pore, intragranular dissolved pore and mould pore. The major factors influencing the properties of the sandstone reservoirs are sedimentary environment, particle features, composition and content of interstitial matter, and the strength of diagenetic transformation. The reservoirs with relatively high quality usually occur in coarse channel sands with high content of quartz and are influenced by diagenesis and interstitial matter.