摘要
为了解南海神狐海底含甲烷水合物沉积地层的工程地质和力学性质,使用钻取自当地的多孔沉积细砂,在可燃冰三轴原位力学测试平台上开展了当地环境下的含甲烷水合物沉积物试样的生成及随后的初步原位三轴力学测试。设计2℃和5℃两个环境,设计围压为9 MPa^15 MPa,水合物含量为50%,测试结果表明试样轴向应力、轴差应力、弹性模量随围压变化表现基本相同,在12 MPa以前均随围压增大,在12 MPa^14 MPa间达到其峰值后下降;而应力–应变峰值不同,2℃时试样峰值强度展先降低然后再升高,而5℃时则为先升高然后再降低,相较而言在2℃时试样的变化比较平缓而在5℃时变化较大;同时2℃时试样的轴向应力、轴差应力和弹性模量比在5℃时更大,在2℃时和在15 MPa围压时该试样的应力/应变变化也比分别在5℃时和在10 MPa下大些,说明在高围压和低温度时含甲烷水合物沉积物力学强度更大。高压低温环境下含水合物沉积地层更可能展现出弹塑性力学特征。
In order to understand the geological and mechanical characteristics of the methane hydrate-bearing sediments in Shenhu area of South China Sea,a group of preliminary tri-axial mechanical tests were carried out.The temperatures were set as2oC and5oC separately,and the scope of the confining pressure was9MPa^15MPa,with hydrate content of50%.The results indicate that the axial stresses,deviator stresses and elasticity modulus show similar changes according to the confining pressure.They increase with the confining pressures before12MPa.In the range of12MPa^14MPa they reach their peaks and then begin to decline.The peak of the stress-strain relationships at the twotemperatures are different,it decreases firstly and then increases at2oC,but increases firstly and then decreases at5oC.The axial stress,deviator stress and elasticity modulus at2oC are larger than at5oC,and the stress/strain changes at2oC&15MPa are also larger than at5oC&10MPa respectively.It proves that the hydrate-bearing porous media possess a stronger mechanical strength under the surroundings of high pressure and low temperature.
作者
关进安
卢静生
梁德青
李栋梁
万丽华
GUAN Jin-an;LU Jing-sheng;LIANG De-qing;LI Dong-liang;WAN Li-hua(Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China;Key Laboratory of Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640, China;Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou 510640, China)
出处
《新能源进展》
2017年第1期40-46,共7页
Advances in New and Renewable Energy
基金
国家自然科学基金(41374149
51474197
51661165011
51576197)
国家海洋地质专项项目(GHZ2012006003)
关键词
南海神狐海域
含水合物沉积物
三轴力学测试
围压
力学强度
Shenhu area of South China Sea
hydrate-bearing sediment
tri-axial test
confining pressure
mechanical strength
