Analysis On Sand Production In Hydrate Exploitation In The South China Sea

As a clean energy in twenty-first Century,natural gas hydrate has the characteristics of wide distribution,large amount of resources,high energy density and so on.Based on the current international energy situation,more and more attention has been paid to the exploitation of natural gas hydrate.In the process of hydrate exploitation,because of the decomposition of hydrate,the formation has the characteristics of low strength,weak cementation and high porosity,which can easily lead to the formation of sand and sand,which has a great impact on production.Therefore,it is of great significance to analyze the risk of sand production in gas hydrate formation.Based on the summary analysis of the northern South China Sea gas hydrate reservoir geological condition,mining process for gas hydrate,using conventional unconsolidated sandstone reservoir exploitation sand research method,and its formation mechanism of sand as a guide,combined with the characteristics of gas hydrate formation,establishment of hydrate formation and fluid solid coupling of sand mining model,simulation software and the two development of the finite element software by mining,the influence factors of sand mining in the analysis of gas hydrate formation.The results show that the decomposition of hydrate formation sand obviously;with the increase of the pressure drop,gas hydrate increases,and hydrate formation extent of sand and sand range will be increased,and the maximum plastic strain with the increase of production increased pressure increases with the increase of the pressure drop well;the higher the temperature,the hydrate formation sand is more serious,but the temperature for sanding the influence of relative pressure;formation of absolute permeability of sand has a certain effect,the greater the absolute formation permeability,hydrate formation sand more serious;at the same pressure,formation in uniform horizontal stress state when the sand with minimumhorizontal stress non-uniform degree,sanding the scope and severity of larger and larger increase to hydrate;There is no clear relationship between the severity of sand production and the initial hydrate saturation.