天然气勘探与开发2026，Vol.49Issue(5)：34-45,12.DOI:10.12055/gaskk.issn.1673-3177.20260067
深水环境水下高地页岩气陆源碳酸盐岩碎屑储层发育新模式及地震预测
New development model and seismic prediction of terrigenous carbonate clastic shale gas reservoirs in deep-water highlands
摘要
Abstract
To overcome the limitations of the traditional deep-water low-energy standing water environment shale sedimentation theory,clarify the formation mechanism and shale gas enrichment patterns of thin and high porosity shale reservoirs in the Ordovician-Silurian transitional period underwater highlands in the southern Sichuan Basin,and improve the sedimentary development model of shale gas reservoirs,this study integrated core observations,thin-section identification,geochemical testing,3D seismic interpretation,and rock-physics modeling to conduct sedimentary dynamics analysis.Multi-scale paleogeomorphology was meticulously restored using the impression method and flattening techniques.Micro-geomorphological features such as scour channels and sheet sand bodies were delineated using various seismic attributes.Ultimately,a Bayesian probabilistic lithology inversion model was constructed to establish a"sweet spot"evaluation system for reservoirs that integrates"macroscopic paleogeomorphology,microscopic sedimentary facies,and later preservation conditions".The following results are obtained.(ⅰ)High-energy fluid flows such as storm flows and contour flow selectively unload terrestrial carbonate clastics when encountering underwater highlands,forming high-quality shale reservoirs rich in carbonate minerals,high in quartz,and poor in clay.The formation shrinks and thins,and rapid burial can efficiently preserve organic matter.The strata condensed and thinned,while rapid burial effectively preserved organic matter.(ⅱ)The third-order terrace of the underwater highland is the most favorable zone for high-quality reservoir development and shale gas enrichment,with reservoir heterogeneity controlled by scour ditches and sheet sand bodies.The highland reservoirs exhibit average porosity ranging from 6%to 10%and gas content exceeding 7 m3/t,significantly outperforming the muddy shales in the lowlands.(ⅲ)The multi-technique integrated prediction workflow can accurately delineate favorable exploration areas with porosity exceeding 5.5%.It is concluded that paleogeomorphology is the core controlling factor for reservoir development,and micro-geomorphic units determine the distribution of high-yield"sweet spot"reservoirs.Future shale gas exploration strategies in the southern Sichuan Basin should shift from targeting thick muddy shales to high-energy,coarse-grained terrigenous carbonate clastic enrichment zones on underwater highlands.关键词
四川盆地/陆源碳酸盐岩碎屑/选择性卸载/古地貌/储层发育新模式/页岩气/高孔隙度/"甜点"储层Key words
Sichuan Basin/Terrigenous carbonate clastic rock/Selective unloading/Paleogeomorphology/New reservoir development model/Shale gas/High porosity/"Sweet spot"reservoir分类
能源科技引用本文复制引用
杨晓,周津宇,周春晖,何奇,朱亚东,张海杰,王小兰,邓小江,司国帅,张入月,李阳静..深水环境水下高地页岩气陆源碳酸盐岩碎屑储层发育新模式及地震预测[J].天然气勘探与开发,2026,49(5):34-45,12.基金项目
四川盆地深层超深层碳酸盐岩气藏勘探开发技术与集成示范专项课题"复杂碳酸盐岩上产区块评价与优选技术研究及应用"(编号:2025DZ1402501). （编号:2025DZ1402501）
