冀中饶阳凹陷蠡县斜坡北段古近系沙河街组沉积相及成藏有利区带

Sedimentary facies and favorable area of hydrocarbon accumulation of the Paleogene Shahejie Formation in northern Lixian Slope of Raoyang Sag in central Hebei Province

通过沉积环境、沉积特征、测井相和地震相等综合分析,认为蠡县斜坡北部主要目的层段古近系沙河街组沙一下段、沙二段及沙三上段发育退积式扇三角洲、辫状河和进积式辫状河三角洲3种沉积相类型。研究结果表明,蠡县斜坡北部沙一下段半环形扇三角洲前缘相带、沙二段河流相分流河道的主体部位及沙三上段辫状河三角洲各期分流河道的边缘相带砂体,是油气藏的主要储集体,其储集物性良好,加上良好的烃源岩层和有利的盖层,具有形成油气藏的优越条件,因此是下一步油藏勘探的重点,其中沙三段将是圈闭优选的主要突破口。

Through depositional environment, sedimentary characteristics, single well sedimentary fa- cies and seismic facies analysis, it is concluded that fan-delta, braided fluvial, braided fluvial-delta depo- sitional systems were developed during the deposition of the lower submember of the Member 1, the Mem- ber 2 and the upper submember of the Member 3 of the Paleogene Shahejie Formation in Lixian Slope. The main reservoirs include the semi-circular delta front facies of the lower submember of the Member 1 of the Paleogene Shahejie Formation, the main parts of the fluvial distributary channel of the Member 2 of the Pa- leogene Shahejie Formation, the distal parts of the distributary channel facies of the upper submember of the Member 3 of the Paleogene Shahejie Formation. They have good reservoir properties and are favorable for hydrocarbon accumulations. With the favorable conditions for formation of oil and gas accumulations, they are the favorable targets for further exploration.