US 12,071,837 B2
Methods of providing wellbores for electromagnetic heating of underground hydrocarbon formations and apparatus thereof
Lynn P. Tessier, Calgary (CA); Shane Matthews, Calgary (CA); and Michal M. Okoniewski, Calgary (CA)
Assigned to Acceleware Ltd., Calgary (CA)
Appl. No. 18/012,092
Filed by Acceleware Ltd., Calgary (CA)
PCT Filed Jun. 17, 2021, PCT No. PCT/CA2021/050829
§ 371(c)(1), (2) Date Dec. 21, 2022,
PCT Pub. No. WO2021/258191, PCT Pub. Date Dec. 30, 2021.
Claims priority of provisional application 63/043,176, filed on Jun. 24, 2020.
Prior Publication US 2023/0235651 A1, Jul. 27, 2023
Int. Cl. E21B 36/04 (2006.01); E21B 17/02 (2006.01); E21B 43/24 (2006.01)
CPC E21B 43/2401 (2013.01) [E21B 17/023 (2013.01)] 25 Claims
OG exemplary drawing
 
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.