天然气水合物分解对地层和管道稳定性影响的数值模拟

利用ABAQUS有限元程序,对海底管道及其附近地层的应力和位移场随着水合物分解范围逐渐扩大的变化情况进行了数值模拟计算。结果表明,水合物分解对管道、地层的变形和应力分布的影响显著,随着水合物分解范围的扩大,管道和地层的变形显著扩大,管道由小变形逐渐变化为整体倾倒变形,即失稳。在工程设计中,为保证地层中管道的安全,应严格控制管道附近水合物的分解范围。

Numerical analysis of the effects of gas hydrate dissociation on the stability of deposits and pipes

By use of the finite element software ABAQUS,the stress and displacement distributions of the subsea pipe and deposits surrounding the pipe along with the development of the gas hydrate dissociation area are simulated numerically.The results show that the gas hydrate dissociation has obvious effects on the distributions of stress and displacement of the pipe and deposits.With the development of gas hydrate dissociation area,the displacements of pipe and deposits increase obviously,the deformation of the pipe is from small to large and finally wholly tilt,i.e.instability.In order to ensure the safety of pipe embedded in the gas hydrate deposits,the gas hydrate dissociation area surrounding the pipe should be controlled strictly in the design.