摘要
富有机质页岩微观孔隙结构是影响页岩油气富集的重要因素,但热演化过程中的孔隙结构变化特征不甚清楚,是当前领域研究的难点.用新疆三塘湖盆地中二叠统芦草沟组低成熟油页岩样品开展高温高压半封闭体系热模拟实验,对各温度阶段的样品进行抽提,利用低温吸附技术定量表征未抽提和抽提样品的孔隙结构,揭示低熟到过成熟页岩样品的孔隙演化特征.结果表明:低熟-成熟阶段,中、大孔量随热模拟温度上升而降低,微孔量先降低再升高,高压及滞留油/沥青对所有孔隙均有一定的抑制作用;高-过成熟阶段,孔含量明显上升,残留沥青中会产生微孔及中、大孔.在热模拟实验中温度、压力条件对孔隙结构具有重要影响,有机质演化产物与孔隙演化趋势紧密相关.
The microscopic pore structure of organic-rich shale is an important factor affecting the enrichment of shale gas,but the characteristics of pore structure change during thermal evolution are not clear,which is difficult for the current research.Taking the low-mature oil shale samples of the Middle Permian Lucaogou Formation in the Santanghu Basin,Xinjiang as an example,a high-temperature and high-pressure semi-closed pyrolysis experiment was carried out,and the thermal simulation samples at various temperature stages were extracted,using low-temperature adsorption technique to characterize the pore structure of the un-extracted and extracted sample and to reveal the pore evolution characteristics of the low mature to over mature shale samples.The results show that in the low-mature to mature stage,the content of mesopores decreases with the increase of thermal simulation temperature,and the micropore content decreases first and then rises.High pressure and residual oil/bitumen have certain inhibitory effect for all pores.While at the high maturity stage,the pore content increases significantly,and the micropore and mesopore are generated in the residual bitumen.It indicates that temperature and pressure conditions have important influence on pore structure in thermal simulation experiments.The thermal evolution of organic matter and its evolution products are closely related to the evolution trend of shale pores.
作者
张毅
胡守志
廖泽文
徐建兵
沈传波
Zhang Yi;Hu Shouzhi;Liao Zewen;Xu Jianbing;Shen Chuanbo(Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education,China University of Geosciences,Wuhan 430074,China;Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2019年第3期983-992,共10页
Earth Science
基金
国家自然科学基金面上项目(No.41572109)
国家科技重大专项子课题(Nos.2016ZX05024-002-005
2017ZX05032-002-004)
湖北省自然科学杰出青年基金项目(No.2016CFA055)
关键词
三塘湖盆地
芦草沟组页岩
热模拟
孔隙演化
沥青
石油地质
Santanghu Basin
Lucaogou Formation shale
pyrolysis experiment
pore evolution
bitumen
petroleum geology
