下寺湾油田龙咀沟地区长2油层组沉积相特征及其对油层的控制作用

Characteristics and control effect on oil reservoirs of sedimentary microfacies of Chang-2 reservoirs of Yanchang Formation in Xiasiwan Oilfield

根据岩心观察和薄片鉴定结果,以及测井资料和试油资料,结合前人研究成果,对下寺湾油田龙咀沟地区长2油层组沉积相特征进行研究.结果表明:下寺湾油田长2油层组为三角洲前缘亚相沉积,主要的沉积微相为水下分流河道、分流间湾、河道侧翼.其中,水下分流河道微相是主要的油气富集相带,长2油层由下而上的沉积具有一定的继承性;沉积微相对下寺湾油田长2油层的分布及其油井产量有重要控制作用.

The characteristics of sedimentary microfacies of Chang-2 reservoirs of Yanchang Formation in Xiasiwan Oilfield is studied according to core obsercation and thin section identification,logging data and oil test data,as well as previous research results. It is shown that,the Chang-2 reservoirs are delta front subfacies deposit,and their main microfacies include underwater distributary channel, tributary bay and channel flank. Main hydrocarbon accumulation zones are in the underwater distributary channel microfacies,and there is a certain continuity from bottom to top in Chang-2 reservoirs. Sedimentary microfacies has a major control effect on the distribution and oil-gas production of Chang-2 reservoirs.