石油科学通报2026，Vol.11Issue(4)：1264-1282,19.DOI:10.3969/j.issn.2096-1693.2026.01.031
岩石组构与成岩作用耦合约束下的深埋碎屑岩储层差异演化机理研究——以准噶尔盆地盆1井西凹陷风三段为例
Differential evolution mechanism of deeply buried clastic reservoirs under coupled constraints of rock fabric and diagenesis:A case study of the third member of the Fengcheng Formation in the Well Pen-1 west sag,Junggar Basin
摘要
Abstract
In the Well Pen-1 West sag within the central depression of the Junggar Basin,the third member of the Permian Fengcheng Formation(Feng-3 Member)hosts a deeply buried clastic reservoir system that represents a key target for hydrocarbon exploration and reserve enhancement in the region.This study integrates core observations,well logs,cast thin sections,scanning electron microscopy(SEM),and high-pressure mercury intrusion(HPMI)analyses to systematically compare the petrological characteristics,reservoir properties,pore types,and microscopic pore structures of sandstone-conglomerate and siltstone reservoirs in the Feng-3 Member.The aim is to clarify the mechanisms controlling reservoir quality differentiation among clastic reservoirs with different grain sizes.The results reveal that sandstone-conglomerate reservoirs were characterized by relatively high initial porosity.Compaction was a primary cause of pore loss,while some samples were further modified by intensive cementation.As a result,subsequent dissolution contributed only limited porosity enhancement,and the average present-day porosity is approximately 7.14%.In contrast,siltstone reservoirs had relatively lower initial porosity and experienced stronger compaction.However,owing to weaker cementation,they underwent intense organic-acid dissolution driven by hydro-carbon-generation overpressure during deep burial,resulting in the development of a well-connected secondary dissolution pore system.The average porosity increase resulting from dissolution reached 8.27%,and the present-day porosity commonly exceeds 10%,significantly higher than that of the contemporaneous sandstone-conglomerate reservoirs.Reservoir quality in the Fengc-heng Formation Member 3 is jointly controlled by rock fabric and diagenetic processes.Variations in depositional hydrodynamics produced distinct grain sizes,matrix contents,and grain-support structures,which determined the initial pore architecture and subsequent diagenetic evolution pathways.Siltstone reservoirs evolved along a"weak cementation-strong dissolution"pathway,generating abundant secondary pore space and substantially improving reservoir quality,whereas sandstone-conglomerate reservoirs followed a"strong cementation-weak dissolution"pathway and experienced progressive reservoir tightening.These findings reveal the intrinsic mechanisms governing the differential evolution of deeply buried clastic reservoirs with different grain sizes,enhance current understanding of reservoir enhancement in fine-grained clastic rocks,and provide a theoretical basis for reservoir evaluation and hydrocarbon exploration in the Fengcheng Formation and other analogous deep tight clastic reservoirs.关键词
盆1井西凹陷/风城组/成岩作用/孔隙演化/差异机制Key words
Well Pen-1 West Sag/Fengcheng Formation/diagenesis/pore evolution/differential evolution mechanism分类
天文与地球科学引用本文复制引用
高艺珊,朱世发,崔航,尤新才,张磊,晏奇,潘进..岩石组构与成岩作用耦合约束下的深埋碎屑岩储层差异演化机理研究——以准噶尔盆地盆1井西凹陷风三段为例[J].石油科学通报,2026,11(4):1264-1282,19.基金项目
中国石油天然气股份有限公司攻关性应用性科技项目(2023ZZ24YJ01)、国家重大科技专项计划(2025ZD1400302)和新疆维吾尔自治区科技计划资助项目(2025A01009-2)联合资助 （2023ZZ24YJ01）
