US 4,572,299 AGranted

Heater cable installation

AssigneeShell Oil Company

InventorsCor F. Vanegmond, Peter Van Meurs

Life of this patent

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Abstract

A well heater is installed in a well by spooling electrical cable assemblies for heating and supplying power, in proper sequence, on at least one spooling means, unspooling them and attaching them to a heat- and tension-stable support means as the resulting assembly is drawn into the well by a weight attached to the support means.

Claims10

Dependent claims

A process for installing an electrical heater within a well comprising:

spooling and arranging electrical cables to provide at least one spooling means drum containing at least one power supply cable with an innermost end arranged for subsequent connection to a surface located electrical power source and an outermost end connected to one or a series of end-to-end connected metal-sheathed heat-stable power transmitting cables which in turn are spliced to a metal-sheathed temperature stable heating cable having its outermost end connected to, or adapted to be connected to, at least one other heating cable or other circuit-completing electrical conductor;
spooling a relatively flexible strand which is heat and tension stable and is capable of supporting the weight of said cables within a well at the temperature provided by said heating cables with the strand being arranged with an innermost end capable of being suspended within a wellhead and an outermost end capable of being attached to a weight for pulling the strand into the well;
correlating the dimensions and properties of said cables and strands so that the power supply cables, power transmission cables, heater cables and strand have lengths arranged for (a) extending from a surface location to, respectively, the depths selected for the top of the power transmission cables and the heater cables and bottom ends of the heater cables and weight supporting strand and (b) having electrical resistances within the cables such that, while conducting the current required for generating the temperature to which the interval of earth formations is to be heated, relatively insignificant amounts of heating occurs above the interval to be heated;
and
concurrently unspooling said cables and weight supporting strand into the well while attaching the weighting means to the outermost end of the strand, interconnecting the heater cables and attaching all of the cables to at least portions of the strand before those items are lowered into the well.

2 more elements

Dependencies are inferred from the claim text.

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Abstract

A process for installing an electrical heater within a well comprising:

spooling and arranging electrical cables to provide at least one spooling means drum containing at least one power supply cable with an innermost end arranged for subsequent connection to a surface located electrical power source and an outermost end connected to one or a series of end-to-end connected metal-sheathed heat-stable power transmitting cables which in turn are spliced to a metal-sheathed temperature stable heating cable having its outermost end connected to, or adapted to be connected to, at least one other heating cable or other circuit-completing electrical conductor;
spooling a relatively flexible strand which is heat and tension stable and is capable of supporting the weight of said cables within a well at the temperature provided by said heating cables with the strand being arranged with an innermost end capable of being suspended within a wellhead and an outermost end capable of being attached to a weight for pulling the strand into the well;
correlating the dimensions and properties of said cables and strands so that the power supply cables, power transmission cables, heater cables and strand have lengths arranged for (a) extending from a surface location to, respectively, the depths selected for the top of the power transmission cables and the heater cables and bottom ends of the heater cables and weight supporting strand and (b) having electrical resistances within the cables such that, while conducting the current required for generating the temperature to which the interval of earth formations is to be heated, relatively insignificant amounts of heating occurs above the interval to be heated;
and
concurrently unspooling said cables and weight supporting strand into the well while attaching the weighting means to the outermost end of the strand, interconnecting the heater cables and attaching all of the cables to at least portions of the strand before those items are lowered into the well.

2 more elements