东营凹陷含油气系统的划分及评价

Characteristics of petroleum system in Dongying Depression

对渤海湾盆地油气勘探程度较高的东营凹陷第三系含油气系统进行了初步划分和评价。该凹陷发育两套有效烃源岩和多套储集层,存在沙四上—沙四上、沙二段(!)含油气系统和沙三段—沙二段、沙三段(!)2个含油气系统。断裂发育使油气纵向运移十分活跃,两个系统共享某些石油地质条件,具有复合含油气系统的特点。凹陷具有多个生、排烃中心和多期油气生成、聚集成藏过程,各洼陷生成的油气就近运移聚集,形成相对独立的油气系统。以生油洼陷为中心,以各洼陷的油气运移可能到达的最大范围为边界,将其分为4个含油气亚系统。在此基础上,以“藏”为核心,将东营凹陷划分为8个油气成藏系统。对各含油气亚系统和成藏系统进行了初步评价。

Dongying Depression is a typical petroliferous lacustric basin in Bohai Bay Basin and has entered a high-exploration stage. There are two hydrocarbon source rocks and two petroleum systems including Es4-Es3/Es3 （!） and Es4-Es4/Es2 （!） in the Tertiary of Dongying Depression. The vertical hydrocarbon migration is intensively active in this area because of faulting. The two petroleum systems in Dongying Depression share some geological elements for reservoir formation and have the characteristics of some complex petroleum system. Dongying Depression has muhiple centers of hydrocarbon generation and expulsion. The petroleum generation and accumulation systems in every suh-deprcssion are independent and can be divided into four sub-petroleum systems according to the hydrocarbon generation centers and distance of petroleum migration. Based on the division of petroleum system, eight hydrocarbon migration and accumulation units are divided in Dongying Depression. The petroliferous prospects of those sub-petroleum systems and bydrocarbon accumulation units have been evaluated.