摘要:
通过地震、测井和岩心等资料及重矿物变化规律的综合分析,识别出沉积基准面旋回产生的层序界面,在北部湾盆地北部凹陷涠洲组划分出 3个超层序 9个三级层序,并研究了各层序发育的特征及沉积体系构成。盆地充填超层序的发育受控于中长周期基准面变化,层序地层单元在中长周期基准面旋回中所处位置不同,其地层厚度、沉积体系的类型和分布均有显著的不同。通过分析对比确认主要控油层序为超层序 1的层序 2和 3,主要储层赋存于低水位和水进体系域。以基准面旋回为基础,论述了层序与油气储盖组合的关系。
Abstract:
According to the comprehensive anaiysis of the data of weii iogging, core, seismic and change of heavy-minera, under the guide of the thought and methodoiogy of high-resoiution seguence stratigraphy, and identification of seguence boundary generated by base-ievei cycie, the seguence stratigraphic framework in Weizhou Formation has been estabiished, and 3 super seguence, 9 seguence have been recognized. Seguence characteristics and sedimentary system formation have been investigated. Spatiaiiy, based on the study of depositionai environment in the unit of chronoiogicai seguence, the system tracts and depositionai system were traced. Temporaiiy, the authors have studied the basin evoiution with every seguence and fauiting action on depositionai fiiiing. The deveiopment of basin-fiii supper seguences in Weizhou Formation is controiied by middie term base-ievei cycie change. Because piace difference of seguence stratigraphic unit in middie term base-ievei cycie, stratigraphic thickness, ciassification and distribution of sedimentary system make obvious difference. Lowstand system trac（t LST）deveioped, there had mostiy deveioped braided river deita, aiiuviai fan, siop fan, muitipie fan, fan deitas and near shore subfan sediments in middie term base-ievei cycie faii-rise eariy stage. Water transgressive system trac（t TST）dformed, there mostiy deveioped fine-grain iake faces sediments in middie term base-ievei cycie rise stage. Highstand system trac（t HST）formed, there mostiy deveioped shaiiow iacustrine, fiuviai-deita and fan deitas sedimentary system in middie term base-ievei cycie iate stage. It couid be conciuded that, in Weizhou Formation, most oii- bearing formations are controiied by seguence 2 and seguence 3 of supper seguence 1, and reservoirs are mostiy sandbody in LST and TST. The seai and structure jointiy made the composite traps. The important commerciai accumuiation of oii and gas were formed in North sag of Beibuwan basin.
点击查看大图
下载:
