东营凹陷八面河地区坡折带特征及其对地层岩性圈闭的控制作用

Patterns of the slope-breaks in Bamianhe area of Dongying Sag and the controls of the slope-breaks on subtletraps

通过对东营凹陷八面河地区广利东洼陷边缘坡折带的识别标志、成因机制以及演化规律的研究,总结了该区坡折带对于地层岩性圈闭的控制作用,以便为地层岩性油气藏的勘探提供依据.研究表明,该区广利东洼陷边缘发育挠曲坡折带和断裂坡折带,构造活动是形成坡折带的主要因素.坡折带的演化规律与构造活动的阶段性演化或幕式构造作用相对应,也表现出多期性、幕式活动和差异性活动的特点,而且坡折带规模与构造活动大小有关.坡折带对地层岩性圈闭的控制主要表现为:坡折带附近是地层岩性圈闭发育的有利区带;规模较大的坡折带控制了多数地层岩性圈闭,地层岩性圈闭在纵向上发育具有继承性特点;坡折带在横向上可以存在较大的变化,可形成不同的圈闭类型;坡折带控制下的地层岩性圈闭含油气性十分有利.

On the basis of studying the identification, the genetic mechanism and the evolution of the slope-breaks developed in the border of Guanglidong shallow depression in Dongying Sag, the controls of the slope-breaks on the subtle traps are discussed in order to provide the basis for the exploration of lithologic oil reservoirs. The results indicate that the slope-breaks are fault slope-breaks and bend slope-breaks, and the tectonic movements are the main controlling factors of forming the slope breaks. Matching with the episodic tectonic movements, the evolution of the slope-breaks is also multi-stage and episodic, and their scale is related to the range and intensity of tectonic movements. The controls of the slope-breaks on the subtle straps are reflected in the following aspects: usually, the subtle traps develope near the slope-breaks; the bigger slope-breaks control the distribution of subtle traps; the formation of subtle traps is successive in the longitudinal direction; the types and scales of slope-breaks greatly vary in the landscape orientation, which may form different types of subtle traps; the subtle traps controlled by the slope-breaks are very favorable to oil and gas migration and accumulation.