两种热模拟体系下有机质生气特征对比  

The Comparision of Gas Generation Potential and Model between Two Different Thermal Simulation Systems

作　　者：胡国艺[1] 李志生[1] 罗霞[1] 李剑[1] 蒋助生[1] 王春怡[1] 

机构地区：[1]中国石油勘探开发研究院廊坊分院,河北廊坊065007

出　　处：《沉积学报》2004年第4期718-723,共6页Acta Sedimentologica Sinica

基　　金：973天然气项目(2001CB209100)资助.

摘　　要：对海相Ⅱ1型有机质在封闭体系和开放体系下开展了产气率热模拟实验,并对其在两种体系下的产气率和生气模式进行了对比研究。在开放体系下,样品产气率较低,Ⅱ1型有机质产气率为84.2m3/吨·TOC,但在封闭体系下实验热模拟产气率很高,Ⅱ1型有机质产气率可达371.2m3/吨.TOC;在开放体系下Ⅱ1型有机质大量生气阶段Ro为1.0%～1.5%之间,在封闭体系下Ⅱ1型有机质大量生气阶段在Ro在1.5%～2.5%之间。在不同实验体系下有机质产气率和生气模式的差异主要与有机质的生气机理有关,在开放体系下有机质主要为干酪根裂解气,而在封闭体系下有机质生成的天然气为原油和干酪根裂解的混合气。The gas potential and generation model of type Ⅰ,Ⅱ 1 ,Ⅱ 2 and Ⅲ organic matter in the open system have been studied. The thermal simulations with type Ⅱ 1 organic matter in the open and closed pyrolysis systems have been carried out and gas generation potential and model have been compared in the two kinds of systems. In the open system the gas potential from type Ⅰ is the highest and its potential is about 269.6 l/g·C org . The gas potential from type Ⅲ is the lowest and its potential is only 26.3 l/g · C org . The gas potential from type Ⅱ 1 in the closed system is more than that in the open system. In the closed system the gas potential is up to 371.2 l/g·C org . , which is about 4.4 times higher than that in the open system. This means that the cracking mechanisms are not different in these two kinds of pyrolysis systems. In the open system, the gas is mainly generated from kerogen by primary cracking, but in the closed system it is generated from kerogen and liquid hydrocarbon by primary and secondary cracking. The gas generation model from type Ⅱ 1 is different in this two kinds of cracking process. The main evolution stage of gas generation by primary cracking (from kerogen) is from R o(%)=1.0 to 1.5 and that by secondary cracking (from liquid hydrocarbon) is from R o(%)=1.5 to 2.5.

关 键 词：有机质 干酪根 海相 热模拟实验 TOC 裂解气 对比 产气率 封闭体系 原油 

分 类 号：P618[天文地球—矿床学] TE122[天文地球—地质学]