鄂尔多斯盆地子长地区上古生界盒8段储层特征

陕西延长石油(集团)有限责任公司研究院,陕西 西安 710069

储层特征; 子长地区; 盒8段; 储层控制因素; 鄂尔多斯盆地

Characteristics of He 8 member reservoir of Upper Paleozoic in Zichang area,Ordos Basin
SHANG Ting

(Research Institute of Shaanxi Yanchang Petroleum Co.,Ltd.,Xi'an 710069,China)

reservoir characteristics; Zichang area; He 8 gas reservoir; influential factor; Ordos basin

DOI: 10.13800/j.cnki.xakjdxxb.2015.0516

备注

子长地区二叠系盒8段气层组研究程度较低,弄清该区的储层特征及其控制因素具有非常重大的意义。通过储层岩石学、孔隙类型、储层物性、孔隙结构及储层控制因素的研究,总结了盒8储层的特征,分析了储层的控制因素。结果 表明:该区砂岩组成为岩屑砂岩、岩屑石英砂岩和石英砂岩; 储层孔隙类型以溶孔和晶间孔为主,含少量微裂缝; 盒8储层物性分析,孔隙度平均5.36%,渗透率平均0.33×10-3 μm2,并且盒81段物性好于盒82段; 压汞实验表明孔喉偏小,孔喉分选和连通性一般等特点,整体表现出低孔、低渗储层较致密的特征。沉积作用控制了砂体的展布,砂岩粒度较大、成分成熟度较高的河道主砂体发育储层孔隙度和渗透性较高; 成岩作用控制了储层的分布,较强的压实作用、压溶作用、粘土矿物胶结作用,缺乏的溶蚀作用,是造成子长东地区低孔、低渗储层的原因。

He 8 gas reservoir in Zichang area of Ordos Basin is still in the low level research. It is important to investigate the reservoir characteristics and controlling factors in this area. By the research of the reservoir petrology,physical properties, pore structure and influential factor of reservoir, summarized the reservoir characteristic and analyzed the controlling factors of reservoir. The results show that the composition of the rock types are mainly lithic sandstone, lithic quartz sandstone and quartz sandstone, the pore types are mainly intergranular pore and dissolved pore and containing a small amount of micro cracks. The average porosity and permeability are 5.36% and 0.33×10-3 μm2,and the He 81 reservoir's physical property is a little better than that of the He 82. Mercury injection experiment shows that the small pore throat, general pore throat sorting and connectivity. The reservoir overall is low porosity and permeability compact. The cause of relatively high permeability reservoir is the main sedimentary and diagenesis, among them the sedimentation controlled the distribution of sand bodies growth.The relatively high permeability reservoir is in the main part of the river which have big particle size with high maturity composition. Favorable diagenesis controlled distribution of relatively high permeability reservoir, with strong compaction,pressolution, clay mineral cementation and weak corrosion, which is an important cause leading to relatively low permeability reservoir in Zichang area.