地质学报2025，Vol.99Issue(12)：4120-4139,20.DOI:10.19762/j.cnki.dizhixuebao.2024374
湖盆类型控制下的层序充填特征和储盖组合分布:以准噶尔盆地玛湖凹陷风城组和百口泉组为例
Sequence-stratigraphy-filling and reservoir-cap rock assemblage distribution under the control of lake basin types:A case study of the Fengcheng and Baikouquan formations in the Mahu sag,Junggar basin
摘要
Abstract
The Junggar basin,one of China's most significant oil and gas production areas,boasts abundant petroleum reserves.However,research on the basin's lake evolution remains relatively limited,particularly regarding the relationship between lake basin types and the distribution of reservoir-cap rock assemblages during the Permian to Triassic depositional periods.This study utilizes sequence stratigraphy frameworks,integrating structural evolution and paleoclimatic characteristics,to systematically analyze the influence of lake basin types on sequence-stratigraphic filling and reservoir-cap rock assemblage distribution in the Junggar basin.The results show that the Permian-Triassic sequence on the northwestern margin of the Junggar basin can be divided into three supersequences(SSQ1～SSQ3)and eight third-order sequences(SQ1～SQ8).SQ2 is further subdivided into the rift initiation system,rift climax system,and post-rift system tracts,while SQ6 is subdivided into the falling-stage systems,lowstand system,expansion system,and highstand system tracts.During the deposition of SQ2,the basin was characterized by a typical underfilled discharge(UF-D)lake basin.High-quality reservoirs mainly developed in the rift climax system tract,characterized by conglomerates and sandstones with residual intergranular pores and dissolution pores,resulting in relatively high porosity.The source rocks exhibited high productivity,strong anoxic preservation conditions,and weak dilution.The distribution of reservoirs and source rocks in the Fengcheng Formation was controlled by fault activities accompanied by hydrothermal fluid input and arid conditions induced by the Late Paleozoic glaciation.In contrast,the SQ6 deposition period represents a typical overfilled lake basin.High-quality reservoirs mainly developed in the forced regressive and lake expansion system tracts,primarily composed of sandstones.Continuous wave reworking and intermittent exposure increased porosity.The primary hydrocarbon source was the SQ5 source rock,characterized by high productivity,poor preservation conditions,and strong dilution.The distribution of reservoirs in the Baikouquan Formation was controlled by tectonic uplift during the late Hercynian orogeny,the arid Permian-Triassic transitional paleoclimate,and subsequent continuous lake transgression.This study reveals the sedimentary evolution patterns of the Permian to Triassic strata in the northwestern Junggar basin,particularly the sequence-stratigraphic filling characteristics and reservoir-cap rock assemblage distribution controlled by lake basin types.The findings provide valuable insights for studying lake basins with similar structural and climatic settings and offer significant implications for oil and gas exploration.关键词
湖盆类型/沉积层序/储盖组合/风城组/百口泉组Key words
lake basin type/sedimentary sequence/reservoir-cap rock assemblage/Fengcheng Formation/Baikouquan Formation引用本文复制引用
ZHANG Bao,YAN Detian,TANG Yong,ZHENG Menglin,CHANG Qiusheng,WEI Xiaosong,ZHANG Lei,BAI Yu,YU Xing..湖盆类型控制下的层序充填特征和储盖组合分布:以准噶尔盆地玛湖凹陷风城组和百口泉组为例[J].地质学报,2025,99(12):4120-4139,20.基金项目
本文为国家自然科学基金项目(编号41690131)和中国石油前瞻性基础性重大科技项目(编号2021DJ0405)联合资助的成果. （编号41690131）
