高桥地区盒_8段储层特征及主控因素分析

Analysis on Reservoir Characteristics and Main Controlling Factors of the Eighth Member of Xiashihezi Formation in Gaoqiao Region

鄂尔多斯盆地南部高桥地区上古生界储层主要为下石盒子组和山西组砂岩,本次研究目的层段为盒8段。研究表明盒8段主要发育辫状河三角洲沉积体系,前缘水下分流河道微相发育,河道横向反复迁移,纵向多期叠置,砂体呈大面积毯式分布。盒8段岩性受物源区控制,石英砂岩大面积分布,孔隙类型主要以溶蚀孔为主,储层孔隙度在2.0%～10.0%之间,平均8.3%;渗透率在0.1～1.0 mD之间,平均0.748 mD,储层物性表现为"低孔低渗"特征,具有形成大型气田的储层条件。该段储层分布主要受控于主河道砂体展布,溶蚀作用对储层储集性能的提高具有重要意义。

The upper paleozoic reservoirs in the south of Ordos basin（Gaoqiao region） are mainly composed of sandstones of Shanxi and Xiashihezi formations. The target stratum of this study is the eighth member of Xiashihezi formation. Research results show that this stratum mainly develops braided delta sedimentary system, and it develops leading edge underwater distributary channel microfacies, repeating channel migration in the horizontal, multiphase superposition in the vertical, sand bodies blanket distribution in the large area. The lithology of this stratum is controlled by provenance, quartz sandstone is massively distributed, the solution vug is main type of voids, the reservoir porosity is 2.0% to 10.0%, the average is 8.3%;the permeability is 0.1 to 1.0 roD, the average is 0.748 roD, the reservoir quality is expressed as low-porosity and low-permeability, it has reservoir conditions for formation of large gas reservoirs. Reservoir distribution of this stratum is controlled by sand body distribution of drainage line, the denudation is very important to improve capacity of the reservoir.