背景介绍：
Background：
天然气水合物作为一种未来极具潜质的清洁能源，其开采已经成为石油天然气工业新的研究热点。我国海洋深水油气资源潜力巨大，在南海领域已经发现了天然气水合物存在的地球物理及生
物等标志，并成功取得水合物样品。在勘探与开采过程中，温度和压力的改变都会造成水合物的分解和对海底沉积层的机械扰动，窜出的高压气体会引起一系列钻井井控问题或井喷现象。水
合物的分解会削弱沉积层的机械强度，引发海底滑坡、沉积层坍塌等自然灾害，造成钻探设备、海底管道等基础设施的损坏及生命财产损失。正因为如此，研究海底水合物沉积层的力学特性
对海底天然气水合物资源的勘探、开发和运输，以及海底工程设施建设都具有重要意义。
Gas hydrate has attracted the global attention due to its potential as an energy resource. China has huge potential of deepwater oil and gas resources, the
geophysical and biological signs of hydrate existing have been found in the area of South China Sea, .and obtained hydrate samples successfully. While drilling for
exploration and exploitation, the instability can be induced if there is increase in temperature or overburden pressure of the hydrate-bearing sediments, and the gas
trapped in the hydrates can be released abruptly and fiercely. The sudden release of gas can lead to well-control problems and reduce the strength of sediments that
products the submarine slope failure or seafloor instability, make the drill equipment and submarine pipelines damaged. As a result, it is important to study the
mechanical strength of marine hydrate-bearing sediments in order to explore, exploit and transport the gas hydrate safely, and useful to marine construction works.
( a )
( b )
水合物分解触发海底滑坡( a )墨西哥湾( b ) 挪威Storegga断崖
Submarine landslide induced by the dissociation of hydrate ( a ) Gulf of Mexico ( b ) Norway Storegga bluff
研究领域：
天然气水合物安全开采技术研究
天然气水合物基础物性研究
Research field：
Natural gas hydrate safe extraction technology
Basic physical property research of natural gas hydrate
研究任务：
Research Task：
1.温度、水合物饱和度及砂质对地层水合物强度的影响
Effects of temperature, saturation, sandy on strength of hydrate sediments
2. 地层水合物压密实验，确定分解过程中压密系数及渗透率的变化
Measure coefficient of compressibility and permeability in the process of decomposition
3. 地层水合物分解时强度的时间变化及分解率、骨骼构造与机械强度的关系
Measure strength changes with time and relationship of strength between decomposition rate and skeletal structure in the process of decomposition
4. 确定海底水合物分解过程中各种参数对海底地层变形的影响
Effects of various parameters on deformation of submarine stratum
5. 阐明地层水合物力学特性
Clarify mechanical property of hydrate sediments
实验设备介绍：
Introduce of Triaxial Apparatus：
1.本试验机由轴向伺服系统、围压伺服系统、低温控制系统及计算机控制系统组成
This testing apparatus contains axial servo-system, confining pressure servo-system, temperature control system, and computer control system.
2.本试验机不仅能进行剪切、蠕变等常规三轴试验，而且具备水合物原位生成与分解、渗透率测量及高精度体变测量等功能。
The apparatus tested in situ gas hydrate formation and dissociation, permeability measurement and high precision measurement of volume change etc apart from shear and
creep test.
主机配置
Host configuration
DDW-600低温三轴试验机
DDW-600 Low-Temperature Triaxial Apparatus
压力室内部
Inside of the pressure chamber
主要科研成果：
Main Research Results：
1.该项目得到“国家科技重大专项(2008ZX05026-004)”和“国家‘863’计划重大项目(2006AA09A209)”的支持。
This program is supported by Major National S&T Program (No. 2008ZX05026-004) and National High Technology Research and Development Program of China (863 Program)
(No. 2006AA09209)
2.基于本试验机，培养博士生2名，硕士生4名，撰写论文20余篇，提交专利申请2项。
By using this apparatus, we have trained 2 PhD and 4 MPhil students, published more than 20 papers and submitted 2 patent applications.
实验成果展示：
Experimental Results：
应力应变曲线
Stress-strain curve
温度对水合物强度影响
Effect of temperature
围压对水合物强度影响
Effect of confining pressure
应变速率对水合物强度影响
Effect of strain rate
水合物沉积物摩尔应力圆
Mohr-circles of gas hydrate-bearing sediments
