关键词: 致密砂岩气藏, 气水两相, 产能, 水平井, 应力敏感, 滑脱效应

Abstract:

 Gas hydrate has became the most promising clean energy in the 21st century, and note hot exploration is considered as the most effective mining method. Taking a permafrost gas hydrate mining area as an example, on the basis of hydrate dissociation kinetics model, this paper established gas hydrate decomposition thermodynamic model based on the finite volume method, and analyzed the influencing factors for temperature field distribution of gas hydrate. The results show that gas hydrate in a high temperature region is gradually increased and the rate of decomposition is accelerated with the gradual increase of water injection rate and unchanged other conditions. With the gradual increase of porosity and water temperature, high-temperature region is basically the same trends. However, the gas temperature will increase in the surface. Note hot exploration was carried out in this mining area, and the hydrate dissociation velocity is fastest with the water injection rate at 6 m/s and water temperature at 80 ℃, with better economic efficiency. This result can provide theoretical guidance for the heat mining practice.

Key words: tight sandstone gas reservoir , gas-water two phase , productivity , horizontal well , stress sensitivity , slip effect