CAJ | 학술논문

对西湖凹陷天然气组分、轻烃、碳同位素等特征进行了系统地分析，结果表明天然气类型以煤型气与油型气的混源气为主且偏煤型气，其演化成熟度较高，属于Ⅱ型偏煤型母质成熟—过熟阶段的产物，主要来源为平湖组及其下部的烃源岩。通过对原油的物性、饱和烃、碳同位素、轻烃等特征的研究表明，西湖凹陷原油可分为轻质原油与凝析油2种类型。这2种类型原油物性一致，母质来源均有煤的贡献，形成于弱还原的淡水湖沼环境；原油可以分为成熟（Ro＜1．0％）和高熟—过熟（Ro＝1．3％～2．0％）2种类型。
대서호요함천연기조분、경경、탄동위소등특정진행료계통지분석，결과표명천연기류형이매형기여유형기적혼원기위주차편매형기，기연화성숙도교고，속우Ⅱ형편매형모질성숙—과숙계단적산물，주요래원위평호조급기하부적경원암。통과대원유적물성、포화경、탄동위소、경경등특정적연구표명，서호요함원유가분위경질원유여응석유2충류형。저2충류형원유물성일치，모질래원균유매적공헌，형성우약환원적담수호소배경；원유가이분위성숙（Ro＜1．0％）화고숙—과숙（Ro＝1．3％～2．0％）2충류형。
Studies of the composition, light hydrocarbons and carbon isotopes of natural gases from the Xihu Sag showed that the gases were a mix of coal?type ( accounting for the major proportion) and oil?type gases having?high maturities. They were mainly derived from type II source rocks in the PinghuFormation and underlying for?mations during the mature and over?mature stages. Crude oils from the Xihu Sag were classified into light oils and condensates according to studies of their physical properties, saturated hydrocarbons, carbon isotopes and light hydrocarbons. These two types of crude oil showed similar physical properties suggestive of acoal origin, and were generated in fresh water lakeswith weakly anoxic conditions. Some of the crude oils were mature ( Ro<1.0%) and some are high?to over mature ( Ro=1.3%~2.0%) .