摘要
岩石热物性是地热学、工程地质及油气地质等研究领域的关键基础参数。为了揭示孔隙流体介质和饱和度等因素对碎屑岩热导率的影响,本研究选取柴达木盆地新生界不同类型的碎屑岩样品,运用非稳态法测量其热导率。结果显示:碎屑岩热导率随孔隙度的增加而降低,在孔隙度低于5.0%的致密储层样品中,热导率降幅最大可达37.6%;碎屑岩热导率与饱和度呈显著的正相关关系,且含水饱和度对横、纵向热导率的影响均较含油饱和度更显著;碎屑岩烘干状态下和饱和水状态下的热导率各向异性系数范围分别为0.648~1.546和0.840~1.200,说明饱和度对热导率各向异性有减弱作用;石英含量对岩石热导率的影响较大,且富石英碎屑岩脆性大,导致岩石样品中的微裂缝更为发育,而原状地层中的微裂缝通常饱和孔隙流体,推测裂缝的发育在干燥状态下对实际地层热导率及其各向异性有消极影响,但在含水条件下,流体沿微裂缝对流,会显著提高热导率。
Rock thermal physical properties are key parameters in the fields of geothermal,engineering geology,and oil and gas geology.In order to have a clear understanding of the influence of factors such as pore fluid medium and saturation on the thermal conductivity of clastic rocks,in this study,typical clastic rock samples from the Cenozoic of Qaidam basin were selected,and their thermal conductivities were measured by applying the unsteady state method.The thermal conductivity of clastic rocks decreases with the increase of porosity,and the decrease of thermal conductivity can be up to 37.6%in the samples of dense reservoirs with porosity lower than 5.0%.The thermal conductivity of clastic rocks showes a significant positive correlation with the saturation degree,and the effect of water saturation on transverse and longitudinal thermal conductivity is more significant than that of oil saturation.The ranges of thermal conductivity anisotropy coefficients of clastic rocks in dry state and in water-saturated state are 0.648-1.546 and 0.840-1.200,respectively,indicating that the saturation degree has an attenuating effect on the anisotropy of thermal conductivity.The greater effect of quartz content on the thermal conductivity of the rocks and the brittleness of the quartz-rich clastic rocks result in more developed microfractures in the rock samples,whereas microfractures in situ formation are usually saturated with pore fluids,it is hypothesized that the development of fractures negatively affects the actual stratigraphic thermal conductivity and its anisotropy in dry conditions,but under water-bearing conditions,groundwater convection along the microfractures significantly increases the thermal conductivity.
作者
杨国鑫
庞玉茂
马瑞山
郭兴伟
曹慧
蔡来星
Yang Guoxin;Pang Yumao;Ma Ruishan;Guo Xingwei;Cao Hui;Cai Laixing(College of Earth Science and Eng ineering,Shandong University of Science and Technology,Qingdao 266590,Shandong,China;Qingdao Ocean Science and Technology Center,Laoshan Laboratory,Qingdao 266237,Shandong,China;PetroChina Qinghai Oilfield Branch,Dunhuang 736202,Gansu,China;Institute of Marine Science and Technology,Shandong University,Qingdao 266237,Shandong,China;Institute of Sedi mentary Geology,Chengdu University of Technology,Chengdu 610059,China)
出处
《吉林大学学报(地球科学版)》
北大核心
2025年第5期1728-1741,共14页
Journal of Jilin University:Earth Science Edition
基金
国家自然科学基金项目(42476077)
山东省自然科学基金项目(ZR2023MD112)。
关键词
碎屑岩
热导率
孔隙度
流体介质
热导率各向异性
岩石热物性
clastic rocks
thermal conductivity
porosity
fluid medium
anisotropy of thermal conductivity
rock thermal physical properties
