准噶尔盆地玛湖斜坡区三叠系百口泉组储层特征及控制因素

Reservoir characteristics and controlling factors of the Triassic Baikouquan Formation in Mahu slope area, Junggar Basin

为了更有效地在玛湖斜坡区三叠系百口泉组寻找有效储集体,利用岩石薄片、铸体薄片和扫描电镜等资料,对该区岩石学特征、储集空间类型、孔喉结构、储层物性和储层控制因素等进行了研究。结果表明:1该区储层类型主要为扇三角洲平原和前缘亚相的砂砾岩,成分成熟度和结构成熟度均较低,孔喉结构差—中等,平原亚相以原生孔隙为主,前缘亚相以次生孔隙为主,整体表现为低孔、低渗的储层特征;2刚性颗粒发育的地区,压实作用弱,可溶蚀矿物含量高,溶解作用强,储层物性较好;3平原亚相比前缘亚相的压实程度高,且杂基含量较高,溶解作用弱,储层物性相对较差;4压实作用减孔明显,胶结作用减孔不明显,溶蚀作用增孔明显,烃类侵位对成岩作用具有一定的抑制作用,有利于改善储层物性。

By means of rock slices, casting slices and scanning electron microscope, this paper systematically studied the petrologic feature, reservoir space type, pore throat structure, physical properties and controlling factors of the Triassic Baikouquan Formation in Mahu slope area, Junggar Basin, to find out the effective reservoirs in this area. The study results show that： ①The reservoir type is mainly glutenite of fan delta plain and front subfacies, which is characterized by low compositional and structural maturity, poor to moderate pore throat structure, plain subfacies is dominated by primary pores, and front subfacies is mainly of secondary pores, with low porosity and permeability on the whole. ②The area developing rigid particles has the characteristics of weak compaction, high corrosion mineral content, strong dissolution and preferable physical properties. ③The plain subfacies has higher compaction degree, higher matrix content, weaker dissolution and poorer physical properties, comparing to the front subfacies. ④The compaction can reduce the pores obviously, the cementation can not, the dissolution can increase pores, and the hydrocarbon emplacement has definite inhibitory effect on diagenesis, which is helpful to improve the reservoir properties.