| In today’s economic environment,China’s economic growth is unlikely to return to double-digit growth.The reform of energy system is inevitable.China is now paying effort to develop clean energy.Natural gas hydrate has characteristics of clean,widely distributed and large amount of energy resource.Governments and institutes are paying more and more attention to it.Heat injection is considered to be one of the most efficient methods of natural gas hydrate production.Screening for natural gas hydrate reservoir which is suitable for thermal production has profound guiding significance for actual production.By means of adding Kim-Bishnoi kinetic model into the simulator CMG-STARS,then we can use CMG-STARS to simulate gas production from methane hydrates.Afterwards,establishing three kinds of hydrate models,namely Class 1 deposits,Class 2 deposits and Class 3 deposits.We use five simulations to screen for natural gas hydrate reservoir which is suitable for thermal production.It turned out that simple depressurization appears to enjoy an advantage over other production strategies in Class 1.The most promising production strategy in Class 2 deposits of poor reservoir conditions is Depressurization+Huff and puff.For Class3 deposits and Class 2 deposits of good reservoir conditions,the most promising production strategy is depressurization+thermal displacement.According to the simulation results,we apply Depressurization+Huff and puff method and depressurization+thermal displacement method to optimize thermal parameters.it’s found that the appropriate temperature of injection water is between 20 and 60℃and the appropriate rate of injection is between 50 and 100m~3/d.Finaly,establishing hydrate deposit model of the Shenhu Area of the South China Sea.It is found that the most promising production strategy is huff and puff,and the appropriate temperature of injection water is also between 20 and 60℃.The appropriate injection rate is between 50 and 110m~3/d.After orthogonal test analysis,the production of the optimal combination is 4.66×10~6m~3,in the meantime,hydrate recovery is 36.07%. |
