9 Key Factors Affecting Borehole Stability in Gas Hydrates Bearing Formations

Gas hydrate is taken as an alternative energy in future. To explore and exploit gas hydrate buried in certain depth underground, drilling wells is necessary. Because of severe drilling situation and hydrate dissociation, the borehole instability stands out when drilling in gas hydrates bearing formations and is one of the main difficulties confronted with exploring and exploiting natural gas hydrate. The main factors affecting borehole stability include rock physical and mechanical properties, characteristics of hydrate dissociation in porous sediments and drilling fluids. It's an effective way of solving borehole instability of gas hydrate bearing formations by establishing proper thermo-hydro-mechanical coupled elastic & plastic analysis model and developing drilling fluid systems which have high-performance, low-temperature and anti-sloughing based on the study these factors via experiments and numerical simulation.