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Title: Formation-tailored method and apparatus for uniformly heating long subterranean intervals at high temperature

Abstract

A process is described for heating a significantly long interval of subterranean earth formations, comprising: constructing at least one electrical heating cable consisting essentially of (a) an electrically conductive central core having a relatively low electrical resistance, (b) an insulation around the core comprising a compressed mass of solid particles of electrically nonconductive, heat-stable material, and (c) a metal sheath around the core and insulation having significant softening resistance and tensile strength; arranging at least one of the heating cables to provide a heater capable of (a) being extended throughout the interval to be heated, and (b) generating selected temperatures between about 600/sup 0/ to 1000/sup 0/C. in response to a voltage which is less than the sparking potential of the insulation between the core and sheath; arranging a pattern with distance along the heater of combinations of heating cable core cross-sectional areas and heating cable core resistances which pattern is correlated with the pattern of heat conductivity with distance which exists along the interval of earth formations to be heated, so that localized increases and decreases in the average electrical resistance with distance along the heater have magnitude and relative positions similar to those of localized increases and decreasesmore » in the heat conductivity in the adjacent earth formations in a manner capable of resulting in a substantially uniform rate of heat injection into the earth formations; positioning the heater within the borehole of a well; so that the heater is both located along the interval of earth formations to be heated and isolated from contact with fluid flowing into or out of the earth formations to be heated; and operating the heater by applying a voltage sufficient to generate temperatures of about 600/sup 0/ to 1000/sup 0/C. along the heater to effect the substantially uniform rate of heat injection.« less

Inventors:
;
Publication Date:
OSTI Identifier:
6086650
Patent Number(s):
US 4570715
Assignee:
Shell Oil Co., Houston, TX
Resource Type:
Patent
Resource Relation:
Patent File Date: Filed date 6 Apr 1984
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; OIL WELLS; ELECTRIC HEATING; WELL STIMULATION; PETROLEUM; THERMAL RECOVERY; CABLES; ELECTRIC CONDUCTIVITY; ELECTRIC POTENTIAL; ELECTRICAL INSULATORS; HEATERS; HIGH TEMPERATURE; METALS; THERMAL CONDUCTIVITY; VERY HIGH TEMPERATURE; ELECTRICAL EQUIPMENT; ELECTRICAL PROPERTIES; ELEMENTS; ENERGY SOURCES; ENHANCED RECOVERY; EQUIPMENT; FOSSIL FUELS; FUELS; HEATING; PHYSICAL PROPERTIES; RECOVERY; STIMULATION; THERMODYNAMIC PROPERTIES; WELLS; 020300* - Petroleum- Drilling & Production

Citation Formats

Van Meurs, P, and Van Egmond, C F. Formation-tailored method and apparatus for uniformly heating long subterranean intervals at high temperature. United States: N. p., 1986. Web.
Van Meurs, P, & Van Egmond, C F. Formation-tailored method and apparatus for uniformly heating long subterranean intervals at high temperature. United States.
Van Meurs, P, and Van Egmond, C F. Tue . "Formation-tailored method and apparatus for uniformly heating long subterranean intervals at high temperature". United States.
@article{osti_6086650,
title = {Formation-tailored method and apparatus for uniformly heating long subterranean intervals at high temperature},
author = {Van Meurs, P and Van Egmond, C F},
abstractNote = {A process is described for heating a significantly long interval of subterranean earth formations, comprising: constructing at least one electrical heating cable consisting essentially of (a) an electrically conductive central core having a relatively low electrical resistance, (b) an insulation around the core comprising a compressed mass of solid particles of electrically nonconductive, heat-stable material, and (c) a metal sheath around the core and insulation having significant softening resistance and tensile strength; arranging at least one of the heating cables to provide a heater capable of (a) being extended throughout the interval to be heated, and (b) generating selected temperatures between about 600/sup 0/ to 1000/sup 0/C. in response to a voltage which is less than the sparking potential of the insulation between the core and sheath; arranging a pattern with distance along the heater of combinations of heating cable core cross-sectional areas and heating cable core resistances which pattern is correlated with the pattern of heat conductivity with distance which exists along the interval of earth formations to be heated, so that localized increases and decreases in the average electrical resistance with distance along the heater have magnitude and relative positions similar to those of localized increases and decreases in the heat conductivity in the adjacent earth formations in a manner capable of resulting in a substantially uniform rate of heat injection into the earth formations; positioning the heater within the borehole of a well; so that the heater is both located along the interval of earth formations to be heated and isolated from contact with fluid flowing into or out of the earth formations to be heated; and operating the heater by applying a voltage sufficient to generate temperatures of about 600/sup 0/ to 1000/sup 0/C. along the heater to effect the substantially uniform rate of heat injection.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1986},
month = {2}
}