基于流体势约束的潜山油气二次运移优势方向选择——以胜利油田桩海地区古生界潜山为例

Preferred Directions of Petroleum Secondary Migration Constrained by Fluid Potential in Buried Hills:An Example from Paleozoic Buried Hills in Zhuanghai Area,Shengli Oilfield

结合胜利油田桩海地区古生界潜山的油气勘探成果及勘探中存在的问题,定量模拟了其流体势场,并结合输导体系的发育特征,分析了潜山油气二次运移的优势方向。研究表明,油气的二次运移始于排烃后的油汇位置,运移方向宏观上主要受流体势场特征(流体势高低和流体势平面等值线形态等因素)的控制,同时受输导体系的影响,在平面上呈现出有限几个优势方向。对于不整合面发育的潜山,对不整合面分布特征(区域性和局部性)的分析是输导体系研究的前提,在区域不整合面发育的潜山中,输导体系的影响主要体现在断层和碳酸盐岩输导层两个方面,而局部不整合面的存在可以较强地影响优势运移方向。

The fluid potential field in Zhuanghai buried hills, Shengli Oilfield,is calculated and analysed quantitatively on the basis of understanding the actual exploration state in this paper.Then,its characteristics,together with characteristics of the migration pathway system, are taken into account to reveal preferred directions of the petroleum secondary migration in buried hills,which is helpful for the exploration decision.Jumping-off points of petroleum secondary migration are oil-accumulation places,with the macro migration direction controlled by characteristics of the fluid potential field including values of the fluid potential and shapes of fluid potential isolines etc.,as well as characteristics of the pathway system,and several preferred migration directions are showed.The unconformity,one of the key parts of buried hills,requires analysis of its regional and local distribution,on the basis of which the path-way system is studied.In the buried hill with a regional conformity,faults and carrier beds are responsible for the pathway system directions,while the local unconformity will greatly affect the migration direction.