04821798 is referenced by 171 patents and cites 17 patents.

An electrical heating system for an oil well of the kind comprising a well bore extending through and below an oil producing formation to afford a rathole of substantial depth, the well including an electrically conductive first casing section from the earth surface down through the overburden, an electrically conductive second casing section continuing down through the oil producing formation, and a third casing section in the rathole. The first and second casing sections are usually steel pipe. An electrical power supply is connected to primary and secondary electrodes for conductive heating of a portion of the oil producing formation; the primary electrode is an uninsulated portion of the second casing section. The third casing section constitutes an insulator for electrical isolation of the rathole. The first casing section preferably has external insulation for most of its length, and any conductive casing sections extending down below the third casing section, including a float shoe housing if present, preferably has both external and internal electrical insulation.

Title
Heating system for rathole oil well
Application Number
7/59956
Publication Number
4821798
Application Date
June 9, 1987
Publication Date
April 18, 1989
Inventor
Vincent Young
Tulsa
OK, US
Jack E Bridges
Park Ridge
IL, US
Agent
Kinzer Plyer Dorn McEachran & Jambor
Assignee
ORS Development Corporation
OK, US
IPC
E21B 43/24
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