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

Patent · Tue Feb 18 00:00:00 EST 1986

OSTI ID:6086650

Van Meurs, P; Van Egmond, C F

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.

• Assignee: Shell Oil Co., Houston, TX
• Patent Number(s): US 4570715
• OSTI ID: 6086650
• Resource Relation: Patent File Date: Filed date 6 Apr 1984
• Country of Publication: United States
• Language: English

Related Subjects

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