CPC E21B 43/2401 (2013.01) [E21B 17/023 (2013.01)] | 25 Claims |
1. An apparatus for electromagnetic heating of an underground hydrocarbon formation positioned below a ground surface, the apparatus comprising:
two or more wellbore casings positioned within two or more wellbores, the two or more wellbores extending from a proximal end at the ground surface to a distal end at the underground hydrocarbon formation, each of the two or more wellbore casings having a proximal portion and a distal portion, the two or more wellbores being in proximity to one another at a junction;
a first electrical connection between the proximal portions of the two or more wellbore casings for grounding the two or more wellbore casings; and
a second electrical connection between the distal portions of the two or more wellbore casings to provide a short circuit that reduces current traveling on the two or more wellbore casings to the ground surface, the second electrical connection being located at the junction, and the second electrical connection comprising outer surfaces of at least part of the distal portions of the two or more wellbore casings in direct contact with one another.
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