摘要
天然气水合物开发具有重要战略价值与环保效益,但其引发的储层结构失稳可能导致海底地质灾害。系统探究多因素影响下天然气水合物储层力学行为演变规律,对实现其安全高效环保开发尤为重要。通过18组低温高压三轴剪切试验,对比研究了水合物饱和度和围压对于泥质粉砂型水合物储层和砂质水合物储层力学特性的影响。试验结果表明:试样所受围压增大时,对于水合物饱和度高于40%的泥质粉砂型水合物储层和水合物饱和度低于40%的砂质水合物储层的应力-应变曲线都表现出由应变软化向应变硬化改变的趋势;水合物饱和度对于两类储层的抗剪强度影响基本一致,在相同条件下,泥质粉砂型水合物储层的抗剪强度要高于砂质水合物储层的抗剪强度,这与水合物在储层孔隙中的分布有关;水合物饱和度低于40%时,水合物饱和度对于泥质粉砂型水合物储层的粘聚力影响更大,当水合物饱和度小于25%时,泥质粉砂型水合物储层的内摩擦角要大于砂质水合物储层的内摩擦角,当水合物饱和度超过25%时,正好相反。上述结果表明在相同条件下泥质粉砂型水合物储层的力学性能要优于砂质水合物储层。
The development of natural gas hydrate has important strategic value and environmental benefits,but the instability of reservoir structure caused by natural gas hydrate may lead to submarine geological disasters.It is particularly important to systematically investigate the evolution of the mechanical behavior of gas hydrate reservoirs under the influence of multiple factors to realize its safe,efficient and environmentally friendly development.Through 18 sets of low-temperature and high-pressure triaxial shear tests,the effects of hydrate saturation and circumferential pressure on the mechanical properties of argillaceous silt-type hydrate reservoirs and sandy hydrate reservoirs were comparatively investigated.The test results show that:when the peripheral pressure on the specimen increases,the stressstrain curves of the argillaceous silt-type hydrate reservoirs with hydrate saturation higher than 40%and the sandy hydrate reservoir with hydrate saturation lower than 40%show the trend of changing from strain softening to strain hardening;the effect of hydrate saturation on the shear strength of the two types of reservoir is basically the same,and the shear strength of the argillaceous silt-type hydrate reservoirs is higher than that of the sandy hydrate reservoir under the same conditions.Under the same conditions,the shear strength of argillaceous silt-type hydrate reservoirs is higher than that of sandy hydrate reservoir,which is related to the distribution of hydrate in the pore space of the reservoir;hydrate saturation is lower than 40%,hydrate saturation has a greater effect on the cohesion of argillaceous silt-type hydrate reservoirs,when hydrate saturation is less than 25%,the internal friction angle of argillaceous silt-type hydrate reservoirs is greater than that of sandy hydrate reservoir,and it's exactly the opposite when hydrate saturation is When the hydrate saturation is more than 25%,it is exactly the opposite.The above results show that under the same conditions,the mechanical properties of argillaceous silt-type hydrate reservoirs are better than those of sandy hydrate reservoirs.
作者
白策文
温欣
付秀艳
陈晨
BAI Cewen;WEN Xin;FU Xiuyan;CHEN Chen(North China University of Science and Technology,Tangshan 063210,China;Tangshan Polytechnic University,Tangshan 063299,China)
出处
《工业技术与职业教育》
2025年第4期11-17,共7页
Industrial Technology and Vocational Education
基金
河北省高等学校科学技术研究项目“水压致裂深海能源土储层裂缝演化规律及风险评价”(课题编号:ZC2024147),主持人陈晨。
关键词
泥质粉砂型水合物储层
砂质水合物储层
低温高压三轴剪切试验
力学特性
argillaceous silt-type hydrate reservoirs
sandy hydrate reservoirs
low temperature and high pressure triaxial shear test
mechanical property
