东营凹陷永安镇地区断裂特征与油气运移

Characteristics of faults and migration of oil and gas in Yonganzhen Area of Dongying Sag

首先对东营凹陷永安镇地区的断层进行了研究,永安镇地区的断层比较发育,主要断层为东西或近东西走向,倾向以南倾为主,3条二级断层控制了永安镇构造的构造形态,将其切割成由北至南3个依此南掉的台阶。该区不同级别的断层活动具有明显的时空分段性。永安镇地区的断层活动性不是很强,其主要活动期有两期,即沙三上—沙二段沉积时期和东营组沉积时期,馆陶组沉积时期断层活动性逐渐降低,到馆陶末明化镇初期就停止了活动。空间上,主要活动时期(沙三段沉积初期和东营沉积期)断层活动性具有西强东弱的特点。在对东营凹陷永安镇地区的断层发育特征及其活动性分析的基础上,分别采用分层油气显示法、地球化学参数分析及流体性质分析等方法研究了永安镇油田的油气运移规律,明确了断层对油气运移和分布的控制作用。综合研究表明:研究区内不同断层及同一断层的不同部位的活动性均具有较大的差异,油源断层作为主要输导通道在纵向上连接了有效烃源岩和圈闭,控制了该区断块油气藏的形成与富集,对于油气的运移及多层系成藏具有决定性作用。

The article researches the faults of Yonganzhen Oilfield. Faults are well developed in Yonganzhen Area, which are mainly east-west in direction and southward in tendency. Three chief faults control the structural feature of Yonganzhen Area, cutting it into three southward thrown stages. The activity of faults in this area is different in different period and placement. The fault activities are not strong in Yonganzhen Area. The main activities ware in two periods, which are Es3S-Es2 and Ed sedimentary period. Fault activities were gradually decreased during the sedimentary period of Guantao Formation and stopped at the end of Guantao Formation and the early stage of Minghuazhen Formation. The fault activities are intenser in west than that in east. Based on the analysis of fault growing characteristics and activity in Yonganzhen Area, Dongying Sag, the regularity about oil migration is studied by adopting show of oil and gas, analysis of geochemical parameter and fluid property and the fault＇s controlling contribution to the migration and distribution of oil and gas is made clear. The research shows that different faults have great distinction in activity. There is the same situation in different localizations of a fault. As the main migration pathway, oil-source fault joins the efficient hydrocarbon source rock and trap and controls the accumulation and enriching of oil reservoir in the area, which has the decisive effect to forming multi-formation reservoir.