One‐dimensional productivity assessment for on‐field methane hydrate production using CO₂/N₂ mixture gas

Abstract

The direct recovery of methane from gas hydrate‐bearing sediments is demonstrated, where a gaseous mixture of CO 2 + N 2 is used to trigger a replacement reaction in complex phase surroundings. A one‐dimensional high‐pressure reactor (8 m) was designed to test the actual aspects of the replacement reaction occurring in natural gas hydrate (NGH) reservoir conditions. NGH can be converted into CO 2 hydrate by a “replacement mechanism,” which serves double duty as a means of both sustainable energy source extraction and greenhouse gas sequestration. The replacement efficiency controlling totally recovered CH 4 amount is inversely proportional to CO 2 + N 2 injection rate which directly affecting solid ‐ gas contact time. Qualitative/quantitative analysis on compositional profiles at each port reveals that the length more than 5.6 m is required to show noticeable recovery rate for NGH production. These outcomes are expected to establish the optimized key process variables for near future field production tests. © 2014 American Institute of Chemical Engineers AIChE J , 61: 1004–1014, 2015