奈曼油田奈1区块白垩系储层特征

Characteristics of Cretaceous reservoir in Nai 1 Block,Naiman Oilfield

奈曼油田奈1区块的石油主要储集于白垩系九佛堂组上段扇三角洲前缘亚相的砂砾岩、含砾不等粒砂岩、粗砂岩和细砂岩中,砂岩成分成熟度低、结构成熟度中等。九佛堂组上段储层孔隙较发育,孔喉连通较差,孔隙分布不均匀,孔隙类型以溶孔为主,残余粒间孔及微孔次之,平均孔隙度14.59%,平均渗透率29.22×10-3μm2,为低孔、低渗储层。成岩后生作用较弱—中等,成岩作用为早成岩作用后期。优质储层的形成主要受沉积条件、岩性组成和后期成岩改造作用的控制。

In Nai 1 Block located in Naiman Oilfield of Kailu Basin, the petroleum are mainly accumulated in glutenite, gravel- inequigranular sandstone, gritstone and fine sandstone in the fan delta front subfacies in Upper Jiufotang Formation of Cretaceous. The compositional maturity of sandstone is lower and the textural maturity is moderate. The reservoirs show the developed pores, poor pore throat connectivity and uneven pore distribution. The pore type is mainly dissolved pores and secondly residual intergranular pores. The reservoirs belong to low porosity and low permeability reservoir, with average porosity 14.59% and average permeability 29.22×10^-3μm^2. The lithogenic epigenesis is from weak to moderate and the diagenesis is in the later stage of early diagenesis. The high-quality reservoirs are mainly controlled by sedimentary conditions, lithologie construction and later diagenesis.