摘要
六盘山盆地早白垩世烃源岩主要为灰色、灰黑色的湖相泥岩、灰质泥岩和泥灰岩,根据有机岩石学、沉积学和有机地球化学特征分析,该区沉积有机相存在4种类型(深湖-半深湖藻质有机相、滨浅湖草本-藻质有机相、三角洲覆水草本有机相和河流草木混生有机相)。通过分析烃源岩沉积有机相空间变化特征,提出烃源岩发育的有利沉积相带及分布特征:深湖-半深湖藻质有机相在盆地广泛分布,有机质来源以藻类等低等水生生物为主,有机质丰度高,为烃源岩发育的有利生烃相带,对生烃贡献最大;滨浅湖草本-藻质有机相分布范围次之,有机质类型以Ⅱ_1~Ⅱ_2型为主,具备生油和生气的母质基础;三角洲覆水草本有机相和河流草木混生有机相主要分布在盆地北部边缘,母质类型相对较差,对生烃贡献不大。
The Early Cretaceous source rocks in Liupanshan Basin mainly comprise grey and grey-black lacustrine mudstone,lime mudstone,and marlite.According to organic petrology,sedimentology,and organic geochemistry of source rocks,the sedimentary organic facies in this region can be divided into four types:deep-semi deep lacustrine algae,shore-shallow lacustrine herb-algae,delta shallow water herb,and river herb-woody organic facies.The current study provides an objective analysis of the space change of organic facies and suggests favorable facies belts and distribution characteristics of organic facies.The deep-semi deep lacustrine algae organic facies is the most favorable hydrocarbon generation facies and is widely distributed in this basin.Its organic matter is primarily low aquatic organisms like algae,and has relatively higher organic matter abundance.This facies accounts for the largest contribution towards hydrocarbon generation.The shore shallow lacustrine herb algae organic facies is the second most widely distributed facies.The organic matter type is mainlyⅡ1-Ⅱ2,which is the base material for the generation of oil and gas.The delta shallow water herb organic facies and the river herb-woody organic facies are mainly concentrated in the northern margin of the basin and generally have poor organic matter content.Therefore,their contribution towards hydrocarbon generation is low.
作者
陈金燕
CHEN Jin-yan(Exploration and Development Research Institute,Shengli Oil Field Company,SINOPEC,Dongying 257015,China)
出处
《地球化学》
CAS
CSCD
北大核心
2018年第4期325-334,共10页
Geochimica
基金
中国石化页岩油气资源评价及选区专项(YYYQ-ZP-03)
关键词
六盘山盆地
早白垩世
烃源岩
沉积有机相
有机地球化学
Liupanshan Basin
Early Cretaceous
source rock
sedimentary organic facies
organic geochemistry
