实时高温蒸汽加热和高温蒸汽加热冷却后富有机质页岩巴西劈裂试验研究  

Brazilian Splitting Tests on Organic-Rich Shale Under Real-Time High-Temperature Steam Heating or High-Temperature Steam Heating-Cooling

作　　者：冯利鸿 杨栋[1] 康志勤[1] 曹京哲 FENG Lihong;YANG Dong;KANG Zhiqin;CAO Jingzhe(Key Laboratory of In-situ Property Improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,山西太原030024

出　　处：《矿业研究与开发》2024年第6期242-247,共6页Mining Research and Development

基　　金：国家重点研发计划项目(2019YFA0705501)。

摘　　要：在富有机质页岩原位注热开采过程中,热力耦合作用下的抗拉强度直接关系到页岩矿层的强度与稳定性,对页岩的开采有着至关重要的影响。为研究高温蒸汽加热冷却后和实时高温蒸汽加热下页岩劈裂力学特性随温度变化的关系,采用自主研发的实时高温蒸汽试验系统和岩石压力机,对500℃范围内富有机质页岩进行了巴西劈裂试验。研究结果表明:随着温度的升高,高温蒸汽加热冷却后抗拉强度呈先降低后增大再降低的趋势,300℃时达到最大值,峰值应变呈持续上升趋势;实时蒸汽加热下抗拉强度呈先降低后增大趋势,在400℃时降到最低点,峰值应变呈先下降后上升再下降趋势;页岩试样劈裂破坏裂纹为复合型裂纹,主裂纹为贯穿型裂纹,次生裂纹为层理裂纹,且随着温度的升高,次生裂纹数目有所增加。研究结果对流体运移通道改造时确定压裂参数具有一定的工程意义。In the process of in-situ thermal injection mining of organic-rich shale,the tensile strength under thermal coupling is directly related to the strength and stability of shale ore layers,which has a crucial impact on shale mining.In order to study the relationship between the splitting mechanical properties of shale and temperature changes under high-temperature steam heating-cooling or under real-time high-temperature steam heating,Brazilian splitting tests were conducted on organic-rich shale within the range of 500℃using a self-developed real-time high-temperature steam testing system and a rock press.The research results indicate that as the temperature increases,the tensile strength under high-temperature steam heating-cooling shows a trend of first decreasing,then increasing,and then decreasing.It reaches its maximum value at 300℃,and the peak strain shows a continuous upward trend.Under real-time high-temperature steam heating,the tensile strength shows a trend of first decreasing and then increasing,reaching its lowest point at 400℃,and the peak strain shows a trend of first decreasing,then increasing,and then decreasing.The splitting failure cracks of shale samples are composite cracks,with the main cracks being through cracks and the secondary cracks being bedding cracks.Furthermore,the number of secondary cracks increases with the increase of temperature.The research results have certain engineering significance for determining fracturing parameters during the transformation of fluid migration channels.

关 键 词：富有机质页岩 高温蒸汽加热 劈裂特性 破坏裂纹 

分 类 号：TD315[矿业工程—矿井建设]