Geochemical origin of oil in Lower Oligocene reservoirs in Gas Hure,western Qaidam basin

Li Sumei; Liu Luofu; Wang Tieguan

doi:10.11743/ogg20040613

Views : 0 下载量: 711 CSCD: 0

PDF
Export
Share
Collection
Album

Geochemical origin of oil in Lower Oligocene reservoirs in Gas Hure,western Qaidam basin
Vol. 25, Issue 6, Pages: 666-670(2004)
Online First：25 December 2004，

Published：2004
DOI： 10.11743/ogg20040613
稿件说明：

移动端阅览

DOI：

Li Sumei, Liu Luofu, Wang Tieguan. Geochemical origin of oil in Lower Oligocene reservoirs in Gas Hure,western Qaidam basin[J]. 2004, 25(6): 666-670. DOI： 10.11743/ogg20040613.

摘要

有机地球化学分析表明

尕斯库勒渐新统下部油藏原油为典型的盐湖相油

既有低熟油特征也有成熟油特征。油源对比表明

尕斯库勒渐新统下部油藏原油主要来自邻区埋深大于3500m的下第三系接近成熟或成熟的烃源岩。下第三系烃源岩形成于高钙多盐、强还原条件下的盐湖环境。烃源岩中盐和高含量的碳酸盐对甾、萜类化合物异构化有明显的抑制作用

导致下第三系烃源岩成熟滞后。尕斯库勒渐新统下部油藏中

目前找到的原油主要为低熟油

未熟油与成熟油发现不多。经分析

成熟的烃源岩分布在埋深大于4000m的深层

因此

深层具有寻找成熟油的潜力。

Abstract

Organic geochemical analysis shows that oils in the lower Oligocene reservoirs in Gas Hure

western Qaidam basin

are of typical salt lake origin and have the characteristics of both low mature oil and mature oil. Source correlation shows that oils in the lower Oligocene reservoirs in Gas Hure were mainly sourced from the lower Tertiary near mature or mature source rocks buried over 3500m in the adjacent area

which were deposited in salt lakes with high concentration of calcium and salt in strong reducing environment. Salt and high carbonate content in the source rocks significantly inhibited isomerization of steroid and terpenoid

wich would delay the maturation of lower Tertiary source rocks. Oils currently discovered in the lower Oligocene reservoirs in Gas Hure are mainly low mature oil

with rare immature and mature oils. Analysis shows that mature source rocks are mainly distributed in deep layers with a burial depth of over 4000m

thus deep layers would be the potential targets for discovering mature oils.