论文部分内容阅读
沉积盆地古水深恢复及其演化是含油气盆地研究的重要内容之一,是烃源岩、储集层和盖层及油气成藏的控制因素之一。用地震方法解析三角洲前积层的厚度来研究水深是一个比较可靠的方法。文章采用这一方法,并结合部分测井、录井资料及岩心对渤海湾盆地北部的辽西凹陷、中部的南堡凹陷和近南部的东营凹陷沙三中期的古水深进行了研究,发现辽西凹陷在沙三中期发育了一个大型三角洲扇体,在其前缘相发育了含大量灰—深灰色撕裂泥砾的重力流沉积,并获得了辽西凹陷沙三中期最大古水深为1092 m;南堡凹陷沙三中期为一套暗色的泥页岩夹砂岩,最大古水深在552 m;东营凹陷沙三中期为一套暗色泥岩夹含暗色漂浮泥砾的粉砂岩,也为一套重力流沉积,结合史128井—牛43井地震测线的连井剖面,获得了最大古水深在681 m。这三个古水深揭示了整个渤海湾盆地在古近纪沙三中期是一个极超深水(≥500 m)的盆地,为形成大面积分布的优质烃源岩和大型含油气盆地奠定了一定的基础。
Paleohydrological recovery and its evolution in the sedimentary basin is one of the important contents of the research on the petroliferous basins. It is one of the controlling factors for hydrocarbon source rocks, reservoirs and caprocks, and hydrocarbon accumulation. It is a more reliable method to study the water depth by using the seismic method to analyze the thickness of the delta front layer. Based on this method, the paleo-water depths in the Middle Third Member of the Mid-Shahejie Formation in the western Liaoning basin, the Nanpu Sag in the central part of the Bohai Bay Basin, A large delta fan was developed in the middle of the Third Mesozoic and a large amount of gravitational-flow sediments were formed in the frontal facies with a large amount of gray-dark gray tearing debris. The maximum Paleo-water depth of the Middle Third Mesozoic in the western Liaoning was 1092 m. The mid-Shasan Formation of the Sag depression is a set of dark mud-shale sandstone with a maximum paleo-water depth of 552 m. The mid-Shahejie Formation in the Dongying Sag is composed of a set of siltstones with dark-colored floating mud gravel and a set of gravity flow sediments , The maximum paleo-water depth of 681 m was obtained in combination with the continuous well profile of the history 128-Niu 43 seismic line. These three paleo-water depths reveal that the entire Bohai Bay Basin was a very ultra-deep water (≥500 m) basin in the middle of the Shahejie formation in the Paleogene, which laid a certain foundation for the formation of large-scale and well-distributed source rocks and large petroliferous basins basis.