柴达木盆地北缘上三叠统-侏罗系层序特征与含油气系统划分  

Characteristics of Stratigraphic Sequence and Classification of Petroleum Systems in the Nothern Qaidam Basin

作　　者：杨永泰[1] 刘桂侠[1] 贾兴友 管俊亚 

机构地区：[1]中国石油勘探开发科学研究院,北京100083 [2]石油地球物理勘探局物探四处,河北霸县065704

出　　处：《地球学报》2002年第1期67-72,共6页Acta Geoscientica Sinica

基　　金：中国石油天然气股份有限公司"新盆地;新层系;新领域研究和科探井的选择与实践"项目的成果 ( 95 81 1C)

摘　　要：本文应用层序地层学理论将柴达木盆地北缘上三叠统 侏罗系划分为 5个层序、12个体系域 ,确定了该区烃源岩主要赋存在层序Ⅱ和层序Ⅲ的湖侵体系域深湖相泥岩中 ;通过地震剖面追踪 ,圈定了烃源岩赋存于下侏罗统层序Ⅱ和中侏罗统层序Ⅲ中 ,主要以冷湖 南八仙构造带为边界 ;烃源岩发育层段的地震相、沉积相研究表明 ,下侏罗统层序Ⅱ的湖侵体系域发育大面积的滨浅湖、沼泽相沉积 ,在湖盆中心发育面积较小的半深湖 深湖相沉积 ,中侏罗统层序Ⅲ的湖侵体系域仅在鱼卡凹陷及其周缘发育半深湖相 ;依据层序划分、沉积相的研究成果 ,确定了主要生烃中心 ,并依据烃源岩分布特征将柴达木盆地北缘划分为J1( !) R和J2 ( !) E 2个含油气系统 ,其中J1( !) R含油气系统为中等丰度的含油气系统 ,围绕其周围的昆特依构造、冷湖七号构造、伊克雅乌汝构造是有利的勘探目标 ;J2 ( !) E含油气系统面积较小 ,烃源岩厚度较薄 。Based on the theory of stratigaphic sequence,this paper divides the Late Triassic and Jurassic strata into 5 sequences and 12 system tracts of sequence Ⅱ and sequence Ⅲ is the main source rock in the northern Qaidam Basin.Through tracing seismic profiles,the distribution of source rocks is delineated,that is,Lenghu Nanbaxian structural zone is the boundary of Lower Jurassic (sequence Ⅱ) and Middle Jurassic (sequence Ⅲ).The research results of seismic facies and sedimentary facies indicate that the transgressive system tract of sequence Ⅱ develops extensive shallow lake and swamp facies,with small deep lake facies in the deep center,and the transgressive system tract of sequence Ⅲ develops semi deep lake facies only in Yuka sag.Based on the esearch results of stratigraphic sequence and sedimentary facies,this paper defines the oil generating centers.In addition,according to the distribution characteristics of souce rocks,the northern Qaidam Basin is divided into J1(!) R petroleum system and J2(!) E petroleum system.J1(!) R petroleum system is a petroleum system of intermediate abundance,around which Kunteyi structure,Lenghu No.7 structure and Yikeyawuru structure are favorable traps.The distribution and the thickness of J2(!) E petroleum system are limited,and hence the traps around this petroleum system have relatively small exploation potential.

关 键 词：柴达木盆地北缘 上三叠统 侏罗系 层序地层 含油气系统 

分 类 号：P618.13[天文地球—矿床学]