The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 18, 1989
Filed:
Jun. 09, 1987
Jack E Bridges, Park Ridge, IL (US);
Vincent Young, Tulsa, OK (US);
ORS Development Corporation, Tulsa, OK (US);
Abstract
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.