Systems, methods amd processes for use in treating subsurface formations

摘要

A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the tar sands formation from a plurality of heaters located in the formation. Heat is allowed to transfer from the heaters to at least a portion of the formation. A pressure in the portion of the formation is controlled such that the pressure remains below a fracture pressure of the formation overburden while allowing the portion of the formation to heat to a selected average temperature of at least about 280° C. and at most about 300° C. The pressure in the portion of the formation is reduced to a selected pressure after the portion of the formation reaches the selected average temperature.