ROBUST ELECTRICAL HEATING SYSTEMS FOR MINERAL WELLS

• Main Authors: HOFER, KENNETH E, BRIDGES, JACK E, SPENCER, HOMER L, YOUNG, VINCENT R, SMITH, LARRY G, BAJZEK, THOMAS J
• Format: Patent
• Language: English
• Published: 09.06.1993
• Edition: 5
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

Electrical heating systems for mineral wells, particularly oil wells, in which the reservoir or "pay zone" is heat stimulated or some well components (e.g., the tubing) are heated, or both, by electrical power supplied to a multi-perforate electrode have the operating efficiency enhanced by effectively terminating the heating electrode, at both its top and bottom, at a distance inwardly of the pay zone equal to at least three times the diameter of the well casing. In some systems the electrical power connection to the main heating electrode is made through a section of the production tubing of the well, with an electrical contactor interconnecting the tubing and the electrode in the level of the pay zone; these systems also provide electrical isolation, within critical height limits, for the production tubing and the pump rod. Delivery of electrical power downhole of the well may be accomplished through an electrical cable, which may or may not be appropriately armored. Specific electrode constructions combine conductive and insulating materials to counteract galvanic corrosion while maintaining mechanical strength.