地质力学学报2024，Vol.30Issue(3)：408-418,11.DOI:10.12090/j.issn.1006-6616.2023077
柴东地区欧南凹陷上石炭统地震相及沉积展布特征
Seismic facies and sedimentary distribution characteristics of the Upper Carboniferous in the Ounan Depression,eastern Qaidam Basin
摘要
Abstract
[Objective]The Carboniferous system of the Ounan Depression in the eastern Qaidam Basin is a key area for oil and gas exploration in new regions and strata.Drilling and outcrops reveal significant differences in the sedimentary characteristics of the Upper Carboniferous strata across the plane.Previous research,mainly based on outcrop and drilling data,has focused on longitudinal sedimentary evolution and the overall sedimentary background,leaving the distribution characteristics of sedimentary facies unclear.This uncertainty affects the deployment of oil and gas exploration in the Upper Carboniferous of the eastern Qaidam Basin.[Methods]The article focuses on the Upper Carboniferous strata of the Ounan Depression.It predicts the distribution characteristics of sedimentary facies under the guidance of sedimentary model theory using a limited amount of drilling data and 2D seismic data.Utilizing 2D seismic data from the Ounan Depression,it also conducts a detailed study of the internal structure and external geometric features of seismic reflections using seismic facies identification technology.[Results]The comprehensive study identifies six types of seismic facies within the Upper Carboniferous of the Ounan Depression:parallel sheet,sub-parallel sheet,mounded,wedge-shaped,oblique foreset,and chaotic.A planar assemblage map of the seismic facies was developed.By integrating regional geological data,outcrops,well logs,and seismic data,and under the guidance of seismic sedimentology and continental shelf sedimentation theory,the relationship between seismic facies and sedimentary facies in the Upper Carboniferous of the Ounan Depression was established,and the distribution characteristics of sedimentary facies in the study area were predicted.[Conclusion]The results indicate significant differences between the seismic facies in the western and eastern regions of the Ounan Depression.Overall,the western part exhibits lower frequency and more continuous phases compared to the eastern region;the western region also has greater monolayer thickness and a more stable sedimentary environment.From east to west,the Ounan Depression develops a sequential fluvial-delta plain sedimentary system,delta front sedimentary system,and prodelta-deep water shelf sedimentary system.[Significance]The research findings provide a scientific basis for predicting favorable reservoir distribution areas and deploying exploration targets for Carboniferous oil and gas exploration in the eastern region of the Qaidam Basin.关键词
地震相/沉积相/欧南凹陷/上石炭统/柴达木盆地Key words
seismic facies/sedimentary facies/Ounan Depression/Upper Carboniferous/Qaidam Basin分类
天文与地球科学引用本文复制引用
陈程,王利,赵为永,唐建超,魏小洁,方欣欣,张浩..柴东地区欧南凹陷上石炭统地震相及沉积展布特征[J].地质力学学报,2024,30(3):408-418,11.基金项目
国家自然科学基金青年基金项目(42102201) （42102201）
中国地质调查局地质调查项目(DD20230297,DD20230260)This research is financially supported by Youth Fund of the National Natural Science Foundation of China(Grant No.42102201)and the Geological Survey Project of the China Geological Survey(Grants No.DD20230297 and DD20230260). （DD20230297,DD20230260）
