大牛地气田沉积相类型与岸线控藏特征

Sedimentary facies and the character of coastline controlling gas pool accumulation in Daniudi Gasfield.

为明确大牛地气田砂体的分布规律及天然气藏南北差异分布的控制因素,对大牛地气田沉积相与气藏控制规律进行了研究。结果发现,研究区内存在大量的辫状河三角洲—滨浅湖沉积体系,确定大牛地气田主要发育辫状河三角平原和辫状河三角洲前缘沉积。在成藏规律研究的基础上,提出岸线控藏规律:岸线控制气源分布,岸线控制砂体分布,岸线控制储层分布及岸线对天然气运移也的一定的控制作用。岸线控藏理论的提出,为大牛地气田的勘探开发提供了新的理论认识和勘探依据。

In order to figure out the sandstone distrubition and the factors controlling the differencial spread of gas pools accumulation,sedimentary facies and gas pool controlling factors were researched.The result shows that the interested region mainly developed braided-delta and shore meare lithosonic system.Coastline controlled the gas pool obviously.The study area is rich of lacustrine deposition,and the main sedimentary facies included braided-delta plain and braided -delta front,based on these research,the theory that coastline has obviously controlled the gas pools distribution was raised.The main controlling actions included:coastline controlled provenance,coastline controlled sandstone distribution of,coastline controlled reservoir formation,and coastline influenced gas migration to some extent.The discovery of lacustrine facies deposition,especially to propose the idea that lake-coastline controlled gas pools formation,may offer some new theoretical concept and references for the further exploration in the Daniudi Gasfield.