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.
An electrical resistance subterranean heater is provided which is cemented directly in a well borehole without a casing in the borehole within the zone to be heated. The absence of the casing results in an economical installation.
An electrical resistance heater is provided which utilizes a copper-nickel alloy heating cable. This metallurgy heating cable is significantly less prone to failure due to localized overheating because the alloy has a low temperature coefficient of resistance. Used as a well heater, the heating cable permits heating of long segments of subterranean earth formation with a power supply of 400 to 1200 volts.
A down hole heating system for use with oil and gas wells which exhibit less than optimally achievable flow rates because of high oil viscosity and/or blockage by paraffin (or similar meltable petroleum byproducts). The heating unit the present invention includes shielding to prevent physical damage and shortages to electrical connections within the heating unit while down hole (a previously unrecognized source of system failures in prior art systems). The over-all heating system also includes heat retaining components to focus and contain heat in the production zone to promote flow to, and not just within, the production tubing.
A down hole heating system for use with oil and gas wells which exhibit less than optimally achievable flow rates because of high oil viscosity and/or blockage by paraffin (or similar meltable petroleum byproducts). The heating unit the present invention includes shielding to prevent physical damage and shortages to electrical connections within the heating unit while down hole (a previously unrecognized source of system failures in prior art systems). The over-all heating system also includes heat retaining components to focus and contain heat in the production zone to promote flow to, and not just within, the production tubing.
A down hole heating system for use with oil and gas wells which exhibit less than optimally achievable flow rates because of high oil viscosity and/or blockage by paraffin (or similar meltable petroleum byproducts). The heating unit the present invention includes shielding to prevent physical damage and shortages to electrical connections within the heating unit while down hole (a previously unrecognized source of system failures in prior art systems). The over-all heating system also includes heat retaining components to focus and contain heat in the production zone to promote flow to, and not just within, the production tubing.
