Abstract:

How the gas to be effectively produced from hydrate deposits has become a hot research topic. Heat stimulation is regarded as another important way for producing hydrate besides depressurization. However, the production efficiency and economic feasibility of gas production by heat stimulation have not been clearly understood. In this paper, a model for predicting gas production from hydrate deposits by heat stimulation was developed. The model was idealized and simplified by neglecting the effects of heat convection and pressure in sediment. We computed the heat consumption efficiency and gas energy efficiency of gas production by heat stimulation, only considering effect of hydrate dissociation. This model can be used to predict the maximum production efficiency. After thorough analysis of the characteristics of hydrate reservoirs and significant parameters from drilling and sampling research, we calculated the production potential of Shenhu hydrate deposits and investigated the production efficiency and feasibility. The result shows that the maximum amount of cumulative gas production at Shenhu is about 509 m3 per meter in three years, and the production potential is much lower than the industrial criterion for marine production. Therefore, it is concluded that hydrate dissociation rate is very low, and production cost is high and economic value is low under the current production technology.Thus it is unfeasible to produce gas from Shenhu hydrate deposits only considering the thermal conduction.

Key words: gas hydrate, heat stimulation, numerical analysis, Shenhu area