辽河油田东、西部凹陷深层沙河街组沉积相模式

DEPOSITIONAL FACIES AND MODELS OF DEEP BURIAL STRATA OF THE SHAHEJIE FORMATION IN THE EASTERN AND WESTERN DEPRESSIONS OF LIAOHE OIL FIELD

我国东部大多数油田都已进入高含水的开发阶段,为了解决我国后备油气储量严重不足的问题,开展了东部深层(>3500m)的油气勘探工作。近年来的广泛研究表明,深层异常高温、高压区或其附近的良好储集砂体常常是油气聚集的有利区域,因而深层储集砂体的空间分布则是深层隐蔽油气圈闭的主要研究内容。根据辽河油田东、西部凹陷深层沙河街组的沉积特征,划分出3种沉积体系:扇三角洲、滨-浅湖和半深湖-湖底扇体系。对两个地区沉积层序旋回性和砂体韵律进行了统计研究,详细分析了两个研究区砂体在时空上的展布规律,并结合盆地构造演化史,探讨了地层的沉积充填过程,建立了沙河街期一、二、三亚期的沉积演化模式。

Most oil fields in the eastern part of China have entered development stages with high water. In order to solve the problem that the mothball reserve of Chinese petroleum is not enough, it is necessary to undertake the petroleum exploration in deep burial strata. Recent study shows that reservoir sandstones in or near abnormal high temperature and pressure are favourable for petroleum accumulation. Therefore, the spatial distribution of reservoir sandbodies of deep burial strata is main research content to find subtle trap of deep burial strata. On the basis of deposition-al characteristics of deep burial strata of the Shahejie Formation in eastern and western depressions of Liaohe oil field, three depositional systems are identified as following: fan delta, shore to shallow lake and semi-deep lake to sub-lacustrine fan. The distribution of sandbodies in the Shahejie Formation in time and space is studied in details, and the cycle of sedimentary sequence and the rhythm of depositional sandbodies in the study area are analyzed. The three sub-age's depositional models of the Shahejie Formation are set up based on the evolution history of basin structure and the depositional filling process.