准噶尔盆地乌夏地区侏罗系八道湾组储层特征

Reservoir Character of Jurassic Badaowan Formation at Wuxia Area in Junggar Basin

准噶尔盆地乌夏地区侏罗系八道湾组储层发育一套冲积扇、辫状河砂砾岩体。储集空间以次生溶孔、原生粒间孔、剩余粒间孔为主,不同类型的孔隙发育程度及有效性存在差异。孔隙结构总体较好。储层渗透率与孔隙度之间存在较好的半对数相关关系,沉积相及成岩作用是影响储集物性的两大因素。沉积相对储集物性的控制表现在随岩性变化,储层孔渗性能存在明显的变化规律。压实作用是降低储集物性的主要因素,胶结作用是次要因素,后期的溶解作用对物性的改善程度较小。根据研究区储层评价标准,乌夏地区八道湾组储层可评价为孔渗性能中等—好的储层。

The main reservoir of Jurassic Badaowan Formation at Wuxia area is composed of sandbodies of alluvial fan and braided river. The main pore styles of reservoir include the secondary solution pores, initial intergranular pores, residual intergranular pores, the different pore types have the apparent differences with each other in some aspects such as growing degree, abundance and effectiveness. The pore texture is preferable. A good linear relation exists between log permeability and porosity. Sedimentary facies and diagenesis are two factors affecting physical properties. The physical properties of different lithology exist explicit regular pattern, illustrating the control action of sedimentary facies. Compaction is the main factor damaging permeability and porosity, cementation is less important factor, dissolution contributes little to physical property. According to the reservoir evalution criterion of region of interest, Reservoir of Jurassic Badaowan Formation at Wuxia area is classified as moderate and better reservoir.