Abstract: A process for in situ recovery of a tar sand deposit located beneath the earth's surface. A number of boreholes are drilled laterally from subsurface tunnels into the lower portion of the tar sands formation. Initially as a displacing means such as steam is injected into the boreholes, the tar sands become viscous and gravity flow into the bottom of the boreholes. Continuing to apply steam removes the tar sand deposits located in interstitial crevices between the boreholes thereby allowing the steam to flow laterally through these interstitial crevices to nearby boreholes. The steam rises toward the upper portion of the resource formation to create a horizontal heated plane of steam to further remove tar sand deposits located therein.

Abstract: The electrode of an electrode well is formed by inserting a heating device into the borehole and heating the surrounding formation to a temperature at which the hydrocarbon-containing material undergoes thermal cracking, resulting in a coke-like residue surrounding the heater. This conductive and permeable carbonized material serves as an electrode of enlarged radius for further electroheating of the formation.

Abstract: In a pair of electrode wells to be developed for injection and production wells for the electrothermal process for recovering heavy hydrocarbons, the electrodes are formed by inserting a heating device in each borehole and heating the surrounding formation to a temperature at which the hydrocarbon-containing material undergoes thermal cracking, resulting in a coke-like residue surrounding the heater. This conductive and permeable material serves as an electrode, for each well, by which the formation is heated. The heavy hydrocarbon material, such as bitumen found in tar sands, becomes mobile and can be recovered.

Abstract: A subterranean formation is penetrated by a borehole. The formation is fractured and propped with a slurry capable of maintaining a thermit reaction. The slurry is ignited. Upon cooling, a solid metal conductor fin network from the bore into the formation is formed in the fracture system. Energy is transferred between a locus in the borehole and the formation by the network.

Abstract: In displacement processes for recovery of liquid hydrocarbons from a hydrocarbon bearing formation having zones of different permeability wherein such displacement processes comprise injecting a drive fluid through an injection well vertically traversing the formation and recovering by means of a production well the liquid hydrocarbons which are displaced by the injection of the drive fluid; this invention involves an improvement comprising injecting a water insoluble liquid into the permeable zone to increase drive efficiency in the less permeable zone.