含水合物沉积物力学-声学联合试验设备的开发和初步应用

为开展天然气水合物沉积物力学、声学特性的试验研究，对高压-温控三轴试验设备的管道线路进行重新规划，并引入GCTS超声波测试系统。为了检验仪器性能，利用福建标准砂和甲烷气体制备不同水合物饱和度的沉积物试样，开展不同有效围压下的三轴排水剪切试验。结果表明：设备能稳定制备含水合物试样并进行力学试验，试验全过程可实时测试试样的压缩波速和剪切波速；波速变化与试样内部密实度、颗粒分布的变化等密切相关，可反映试样体积的变化及剪切初期的剪胀特性；通过固结后的波速计算试样的泊松比，在0.16～0.31之间。

DEVELOPMENT AND PRELIMINARY APPLICATION OF MECHANICAL-ACOUSTIC TEST SYSTEM FOR HYDRATE-BEARING SEDIMENTS

To study the mechanical and acoustic properties of natural gas hydrate-bearing sediments, the pipelines of high-pressure and temperature-controlled triaxial apparatus are replanned,and GCTs ultrasonic test system is introduced. To verify the reliability of the apparatus,specimens with various hydrate saturations were prepared with Fujian sand and CH₄ gas, and drainage triaxial tests were performed under different effective confining pressures. The results show that hydrate-bearing specimens can be prepared and tested stably, and the compression and shear wave velocity can be measured in real time during tests. The change of wave velocity is related to the change of compactness and particle distribution inside the specimen,and can reflect volume change anddilatancy characteristics. Poisson’s ratios of specimens were calculated by the wave velocities after consolidation,which were about 0.16-0.31.