东营凹陷博兴地区油气成藏动力学研究

Hydrocarbon accumulation dynamics study of Boxing area of Dongying depression

运用油气成藏动力学的理论与方法,和对成藏要素——烃源岩、储集层、盖层、运聚史等的描述,对东营凹陷博兴地区油气成藏动力学及其输导体系、地层压力场特征分别进行了研究.认为平面上异常高压区出现在博兴洼陷中心区,纵向上分布层位为砂三中、下亚段和砂四上亚段,异常压力的分布受暗色泥岩分布和生烃作用的控制,并在一定程度上受到砂体输导层、断层等因素的影响.博兴地区输导系统特别发育,由断层、砂体输导层以及不整合面组成,基本控制了全区的油气分布:高青断层、石村断层、博兴断层控制了研究区油气的纵向运移,砂体输导层的分布控制了油气的平面分布,不整合面在局部地区是油气的重要横向运移通道.最后根据地层压力、烃源岩条件和封闭特征将研究区在纵向上分为3个成藏动力学系统,即自源封闭型、他源半封闭型和他源开放型.

Based on the theory and method of dynamic system of pool forming and the element of petroleum system, such as source rock, reservoir and cap etc, this paper gives a comprehensive research and analysis on the study of fluid conducting system, tectonic stress field and formation pressure of Boxing area of Dongying Depression. The research study shows that there are two abnormal pressure centers which are the Boxing subsag area and Chunhua uplift. The main stratum where the abnormal pressure develop is the third and forth strata of Shahejie Formation and the distribution is controlled by the mudstone, the action of hydrocarbon generating, sandstone conducting system and faults factor. The fluid conducting system of Boxing area, which consist of sand strata, unconformity surface and faults, develop very well and control the oil migration and accumulate. The Gaoqing fault, Shicun fault and Boxing fault dominate the vertical migration of oil, and sand conducing system master the horizontal migration of oil. In the meanwhile, the unconformity surface are the important migration channels in partial areas. The study area divide into three petroleum dynamic system in vertical direction, namely self - sourced ＆ closed, other - sourced ＆ semi - closed and other - sourced ＆ closed types, according to formation pressure, source rock and closure characteristics.