Patent ID: 7621326

Claim:
A method for recovering hydrocarbons from a subterranean formation containing viscous oil, oil shale, tar sands or other heavy hydrocarbons; the method comprising the steps of: (a) drilling a central wellbore down to the hydrocarbon bearing formation by penetrating the formation and the under-burden zones; (b) reaming out a section of the central wellbore to form a viably located production cavity; (c) drilling at least one additional wellbore vertically from the surface and then laterally through the said formation to connect said additional wellbore to the said production cavity and further comprising the step of installing a means for active control of the back pressure in this additional wellbore; (d) providing a plurality of perforations in the said additional wellbore at pre-selected intervals; (e) installing a downhole wellbore packer between upper and lower perforations; (f) implementing a means for forming an annular zone of increased fluid conductivity near the said additional wellbore in the said formation; (g) heating the said formation by injecting a displacing fluid into the formation; (h) collecting oil and water in the said production cavity; (i) lifting the produced fluids and displaced fluids to the surface by using a fluid recovery system.