天热气水合物地层降压开采出砂数值模拟

全世界范围内已开展天然气水合物资源短期试采中大部分都遇到了不同程度的出砂现象,使得天然气水合物资源的商业化一直没有实现。利用水合物地层出砂判断方程模拟研究了天然气水合物地层在开采过程中的出砂程度。模拟结果表明:随着开采时间的增加,天然气水合物地层的最大等效塑性应变随之变大,地层破坏性出砂的风险程度增加;同时,天然气水合物地层出砂现象可分为轻微出砂、暂稳定出砂、快速出砂、后稳定出砂4个阶段。

Numerical Simulation of Sand Production in Natural Gas Hydrate Formation by Depressurization

Most of the short-term production test of natural gas hydrate resources that have been carried out worldwide have encountered different degrees of sand production, which has made the commercialization of natural gas hydrate resources unfulfilled. In this paper, the sand production degree of natural gas hydrate formation during the production process is studied by using the sanding judgment equation of natural gas hydrate formation. The simulation results show that the maximum equivalent plastic strain of natural gas hydrate formation will increase with the increase of exploration time, and the risk of destructive sand production will increase. There are four stages in the sand production of natural gas hydrate formations during the production process.