巴彦浩特盆地东部坳陷石炭系流体势特征及油气运聚单元划分

Fluid potential characteristics of Carboniferous and the division of hydrocarbon migration and accumulation units in the eastern depression of the Bayanhaote Basin

巴彦浩特盆地是油气勘探的重点,但其流体势特征及油气运聚单元始终未进行研究,限制了区域成藏研究及勘探目标的优选。文章探讨巴彦浩特盆东部坳陷石炭系流体势特征及油气运聚单元的划分,从油气运移动力学角度分析巴彦浩特盆地东部坳陷油气运聚规律及原因。以盆地主要成藏时期晚白垩世的构造演化活动为基础,结合该时期的构造格局,计算出巴彦浩特盆地东部坳陷晚白垩世时期石炭系流体势,明确流体势场表现出的油气运聚特征。结果表明晚白垩世时期石炭系总体上表现为自坳陷东部及南部向西部及东南部降低的规律,高势区分布范围较小,主体位于坳陷的东部及南部。在此基础上,可划分为3个油气运聚区8个油气运聚单元。上述流体势特征有利于油气长期运移聚集,较好的油气运聚单元是未来巴彦浩特盆地东部坳陷勘探的主要潜力区。

The Bayanhaote Basin is the focus of hydrocarbon exploration,but its fluid potential characteristics and hydrocarbon migration and accumulation units have not been studied,which limits the optimization of regional hydrocarbon accumulation research and exploration objectives.This paper discusses the fluid potential characteristics of Carboniferous and the division of hydrocarbon migration and accumulation units in the eastern depression of the Bayanhaote Basin.From the perspective of hydrocarbon transportation dynamics,this paper analyzes the hydrocarbon migration and accumulation laws and causes in the eastern depression of the Bayanhaote Basin.Based on the tectonic activity evolution of the basin during the main accumulation period,combined with the tectonic pattern of the period,the Late Cretaceous fluid potentials in the eastern depression of the Bayanhaote Basin were calculated,and the hydrocarbon migration and accumulation characteristics were identified by the fluid potential fields.The results show that the fluid potential field generally decreases from the east and the south to the west and southeast of the depression.The high-potential area has a small range,and the main body is located in the east and south of the depression.On this basis,it can be divided into three areas and eight units for hydrocarbon migration and accumulation.The above-mentioned fluid potential characteristics are conducive to the long-term migration and accumulation of hydrocarbon.The better hydrocarbon migration and accumulation unit is the main potential area for exploration in the eastern depression of the Bayanhaote Basin.