苏里格气田西区储层微观特征研究

Reservoir microscopic characteristics study on western Sulige gas field

利用岩心观察、薄片鉴定和多种分析测试资料对苏里格气田西区储层微观岩石学特征和孔隙结构进行系统研究,结果表明该区盒8段、山西组储集砂岩岩屑含量较高、长石含量低、石英含量高,岩石类型主要为岩屑砂岩,成分成熟度低;储层经深度成岩改造,主要发育溶孔、晶间孔、粒间孔和微裂缝4种孔隙类型,其中,岩石中孔径较大的粒间孔和溶孔提供了油气赋存空间,微裂缝能有效沟通储层提高气井产能;气田整体孔喉组合为细-微孔、细-中喉型,其中主产层盒8下段、山1段孔隙结构整体偏好,对油气富集有利。

By using core observation,thin section identification and various testing data,a systematic study on reservoir microscopic petrological characteristics and pore structure of western Sulige gas field has been carried out.The results show that reservoir sandstone from He-8 member and Shanxi formation is of higher cutting content and lower feldspar content.The rock type is mainly of lithic sandstone with low compositional maturity.Through diagenetic transformation,four kinds of pore types were mainly developed,including dissolved pore,inter-granular pore,inter-crystalline pore and micro-fractures.Among them,with larger aperture,the inter-granular pore and dissolved pore can provide occurrence space for hydrocarbon.Micro-fractures can effectively communicate reservoir and improve gas well capacity.The overall pore combination of the gas field is fine-micropore and fine-medium pore.As the main producing layer,the pore structure of the He-8 lower member and Shan-1 member is good,and it is good for hydrocarbon enrichment.