苏里格气田西部主要含气层段储层特征

苏里格气田西部储层主要发育于二叠系下石盒子组盒8 段及山西组山1 段，其中山1 段为网状河沉积，盒8 下亚段为辫状河沉积，至盒8 上亚段演变为曲流河和网状河沉积。研究区主要含气层段储层岩石类型主要为岩屑砂岩和岩屑质石英砂岩，含有少量石英砂岩，具有成分成熟度低的特征。储层孔隙空间常以组合形式出现，以岩屑溶孔和晶间孔为主，含少量的原生粒间孔。储层孔隙结构具有孔喉小、排驱压力高和主贡献喉道小的特征，平均孔隙度为6.23%，平均渗透率为0.4 mD，为低孔、低渗储层。成岩作用研究认为，盒8 段和山1 段储层目前均处于中成岩阶段B 亚期，储层物性主要受沉积微相的控制以及成岩作用的影响，非均质性明显。

Characteristics of major gas-bearing reservoirs in western Sulige Gas Field

In western Sulige Gas Field, the eighth member of Shihezi Formation and the first member of Shanxi Formation are the major gas-bearing reservoirs. Shan 1 member developed anastomosing river deposit, and He 8 member developed braided river deposit, in which the facies transited from braided river to meandering and anastomosing river from bottom to top. The rock types of the main gas-bearing reservoirs are lithic sandstone and lithic quartz sandstone, with little quartz sandstone, and they are characterized by low compositional maturity. Pore spaces always occur as the combination form, the pore types are mainly composed of debris dissolved pores and intercrystal pores, and little primary intergranular pores. The pore structure has features of small pore-narrow throat, high displacement pressure and narrow main contribution throat. The average porosity is 6.23%, while the average permeability is 0.4 mD, so the reservoir is characterized by low porosity and low permeability. On the basis of diagenesis analysis, the reservoir is in the middle diagenetic phase B. The reservoir properties are mainly controlled by sedimentary microfacies and diagenesis, and the heterogeneity is strong.