摘要
云南陆良盆地面积为３２５ ｋｍ ２ ，盆地内上第三系烃源岩有机物丰度高，通过对有机碳含量、氯仿沥青“ Ａ”和总烃含量、热解生油潜量进行分析，认为绝大多数烃源岩样品已达生油岩标准；通过对岩石热解参数、干酪根稳定同位素和元素组成、煤样组成、族组成和正构烷烃的研究，认为有机质类型绝大多数都属于Ⅱ Ｂ 型；通过对镜质体反射率及正烷烃与族组成的研究，认为该盆地烃源岩属于未成熟阶段；参照国内外学者普遍采用的生物气划分标准，把陆良盆地上第三系天然气划定为生物气。在此基础上，讨论了该盆地生物气形成的３ 个主要条件：①草本腐殖型有机质含量丰富；②水化学特征是还原状况下低矿化度；③地温梯度为３ ．６６ ℃／１００ ｍ ，地面温度２０ ℃。
The area of Luliang Basin in Yunnan Province is 325 km 2 and the abundance of organic matter in the hydrocarbon source rocks of Neogene in the basin is high.By means of the analyses of the organic carbon content,chloroform bitumen “A”,total hydrocarbon content and pyrolysis source potential,it is considered that most of the hydrocarbon source rock samples have reached the standard of source rock;through studying the rock pyrolysis parameters,the stable isotope and elemental composition of kerogen,the coal sample constituent,group composition and normal alkane,it is thought that most of the organic matters belong to the Type Ⅱ B;and by way of the research on the vitrinit reflectance,normal alkane and group composition,it is deemed that the hydrocarbon source rocks in the basin are in the immature stage.Therefore the natural gas in Neogene in Luliang Basin is classified as the biogas in the light of the division standard generally adopted by domestic and foreign scholars.Based on this,three principal conditions of generating biogas in the basin are discussed.These conditions include ①having abundant herbaceous humic organic matters;② having a hydrochemical property of low salinity in reducing environment;and ③ having a geothermal gradient of 3.66℃/m and surface temperature of 20℃.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
1999年第5期21-26,共6页
Natural Gas Industry
关键词
陆良盆地
上第三系
气源岩
生物气
成因
烃源岩
Yunnan,Luliang Basin,Oil source rock,Gas source rock,Feature,Biogas,Origin
