莫西庄油田低渗透储层特征与成因

Characteristics and genesis of low permeability reservoirs in the Moxizhuang oilfield

综合利用岩心观察、薄片鉴定、图像分析、扫描电镜观察、压汞与岩石物性测试等多种技术方法,对准噶尔盆地莫西庄油田侏罗系三工河组低渗透储层特征及其成因进行了研究。结果表明,储层物性总体较差,储集空间以原生粒间孔隙和次生溶蚀孔隙组合为主,孔隙结构类型属中孔—细喉道型;沉积因素对低渗透储层的形成起决定性作用,压实作用强是低渗透储层形成的主要因素;胶结作用损失的原生孔隙度一般小于5%,对储层低渗成因起有限的强化作用;溶蚀作用对储层没能发挥明显的改造作用,是低渗储层形成的一个重要原因。

By integrated use of a number of methods such as core observation,thin section analysis,graphic analysis,SEM observation,mercury injection and petrophysical test,the characteristics and genesis of the Jurassic Sangonghe Formation low permeability reservoir in the Moxizhuang oilfield,Junggar basin have been investigated. From the results,it is indicated that the reservoir has generally poor physical properties. The accumulation space is predominated by primary intergranular pores and secondary dissolved pores,with a medium pore – fine throat type structure. Depositional factors had a deterministic effect on the forming of the low permeability reservoir while strong compaction acted as the major factor. The loss of primary porosity caused by cementation is generally less than 5%,imposing limited enhancement on the low permeability occurrence in the reservoir. Dissolution had no significant reformation effect on the reservoir,being an important cause for the occurrence of the low permeability reservoir.