Producing hydrocarbons by circulating fluid

A system and method for producing hydrocarbons from a subsurface formation includes an injection well 4 disposed in the formation 2, the injection well 4 arranged to inject acirculation fluid. A production well 3 is also disposed in the formation for producing hydrocarbons. A fracture 6 is provided in the formation to provide a communication channel between the injection well 4 and the production well 3, thereby allowing injected circulation fluid to pass from the injection well 4 to the production well 3. The reservoir is heated and the heat may be provided by the circulation fluid or by heaters. Circulation fluid may be separated from production fluid following production