海相油气地质2024，Vol.29Issue(4)：401-412,12.DOI:10.3969/j.issn.1672-9854.2024.04.006
古地貌控制下的退积型三角洲沉积特征及油气地质意义——以准噶尔盆地南缘中东段清水河组为例
Sedimentary characteristic of retrogradational delta under paleo-geomor-phologic control and its petroleum geological significance:an example of the Qingshuihe Formation in central and eastern part of the southern margin in Junggar Basin
摘要
Abstract
Many exploration wells in the southern margin of Junggar Basin have obtained high-production oil and gas flow from the Lower Cretaceous Qingshuihe Formation in wells,which proves that high-quality reservoirs is developed in Qingshuihe Formation.Based on the paleo-geomorphologic data,this paper analyzes the differences in sedimentary facies of the bottom sand body of Qingshuihe Formation,the reasons for the stable distribution of sand bodies,and the distribution patterns of different rock types,by combining analysis of the sand body structures,petrologic characteristics,heavy mineral assemblages and paleocurrent characteristics of the reservoir.The study suggests that before the deposition of Qingshuihe Formation,the paleo-geomorphology of the southern margin in Junggar Basin was characterized by the development of a steep-slope area in the south and a large gentle-slope area in the north,whereas two slope breaks were globally developed in the gentle-slope area.During the depositional period of Qingshuihe Formation,the study area was in the process of lake transgression,and retrogradational braided-river deltas and fan deltas were formed under the control of paleo-geomorphology.In the southern steep-slope area,fan deltas depositional system was developed,and the thickness of sandstone and conglomerate reservoirs is at the range of 10-30 m.In the northern gentle-slope area,three stages of regressive braided-river deltas depositional system were developed under the control of two slope breaks,resulting in the widely developed sandstone reservoirs in the middle and northeastern parts of the southern margin in Junggar Basin.The sandstone reservoir formed by northern and northeastern source system with a thickness of 20-50 m and relatively good physical properties,making it a favorable reservoir development area for the Qingshuihe Formation.关键词
坡折带/古地貌/辫状河三角洲/扇三角洲/清水河组/准噶尔盆地南缘Key words
slope break/paleo-geomorphology/braided-river delta/fan delta/Qingshuihe Formation/southern margin of Junggar Basin分类
能源科技引用本文复制引用
司学强,彭博,郭华军,陈希光,冀冬生,易俊峰,李亚哲,邹志文..古地貌控制下的退积型三角洲沉积特征及油气地质意义——以准噶尔盆地南缘中东段清水河组为例[J].海相油气地质,2024,29(4):401-412,12.基金项目
本文受中国石油集团公司基础性前瞻性重大科技专项(2023ZZ02)下设课题"叠合盆地中下组合规模储层形成机制与分布规律研究"(2023ZZ0204)资助 （2023ZZ02）
