石油勘探与开发2026，Vol.53Issue(1)：81-93,13.DOI:10.11698/PED.202500136SD
陆相页岩油阶段充注-累积充注模式与分异聚集
Staged-cumulative charging and differential accumulation of continental shale oil:A case study of Permian Lucaogou Formation shale oil in Junggar Basin,NW China
摘要
Abstract
In the Jimusaer Sag of the Junggar Basin,crude oils from the upper and lower sweet-spot intervals of the Permian Lucaogou Formation display a pronounced"light-heavy reversal"in oil properties that indicates a fundamental mismatch between oil composition and maturity rock.To resolve this anomaly,this study integrates geological,geochemical,and petrophysical datasets and systematically evaluates the combined roles of thermal evolution,organic facies,wettability,abnormal overpressure,and migration-related fractionation on shale oil composition.On this basis,a"staged charging-cumulative charging"model is proposed to explain compositional heterogeneity in lacustrine shale oils.The results demonstrate that crude-oil composition are jointly controlled by the extent of biomarker depletion,the temporal evolution of hydrocarbon charging,and the openness of the source-reservoir system,rather than by thermal maturity or organic facies alone.The upper sweet-spot interval is interpreted to have functioned as a semi-open system during early stages,in which hydrocarbon generation and expulsion were broadly synchronous,leading to preferential loss of early-generated,biomarker-rich heavy components,whereas progressive shale densification at later stages promoted the retention of highly mature,light hydrocarbons.In contrast,the lower sweet-spot interval represents a relatively closed system,where hydrocarbons generated during multiple stages continuously accumulated and were preserved as mixed charges;superposition of multi-phase fluids progressively weakened sterane isomerization signals,rendering them unreliable indicators of individual charging events or final thermal maturity.This charging behavior provides a reasonable explanation for anomalously low or distorted biomarker parameters observed in intervals of low or similar maturity.Overall,the proposed charging model reconciles the observed reversal in crude-oil properties and,by shifting the interpretive focus from static maturity assessment to charging dynamics,offers a new theoretical basis for understanding lacustrine shale oil accumulation processes,and guiding sweet-spot selection and exploration-development strategies.关键词
页岩油差异性/烃源岩成熟度/原油成熟度/阶段充注-累积充注/滞留动力学/芦草沟组/吉木萨尔凹陷/准噶尔盆地Key words
shale oil heterogeneity/source rock maturity/oil maturity/staged-cumulative charge/retention dynamics/Lucaogou Formation/Jimusaer Sag/Junggar Basin分类
能源科技引用本文复制引用
黄海平,张鸿,马勇..陆相页岩油阶段充注-累积充注模式与分异聚集[J].石油勘探与开发,2026,53(1):81-93,13.基金项目
国家自然科学基金项目(42173030,42302161,42473034) （42173030,42302161,42473034）
科学技术部新型油气勘探开发国家科技重大专项(2025ZD1400803) （2025ZD1400803）
