Downhole control valve for catalytic wellbore heaters

Claim 2

In a catalytic wellbore heater system having a catalytic surface communicating with the interior of well pipe, the improvement comprising: downhole valve means in the well pipe adjacent the catalytic surface for regulating the flow rate of one component of a fuel mixture to the catalytic surface; means for continuously monitoring the temperature adjacent the catalytic surface; and downhole means operably connected to the valve means for controlling the valve means in response to the temperature monitoring means.

Claim 3

The apparatus of claim 1 wherein the valve means comprises a valve stem, a valve seat sized to engage the valve stem, and a motor connected with the valve stem for moving the valve stem toward and away from the valve seat.

Claim 4

The apparatus of claim 2 including electrical energy means, responsive to the temperature monitoring means, for energizing the motor.

Claim 5

The apparatus of claim 1 wherein the controller means comprises means for comparing the sensed temperature adjacent the catalytic section with a preselected temperature range, said comparer means adapted to provide a control signal when the sensed temperature is outside the preselected temperature range, and means reponsive to the control signal for controlling the supply of electrical energy to the valve means.

Claim 6

The apparatus of claim 4 wherein the valve means includes a housing containing a valve stem, a valve seat, and an electrically operated motor connected with the valve stem in a manner such that the valve stem can be moved toward and away from the valve seat, and wherein the motor is also connected with the electrical energy means.

Claim 7

The apparatus of claim 5 wherein the connection between the motor and the valve stem is a spline drive connection and wherein the motor is reversible to allow both clockwise and counterclockwise movement of the motor shaft and connected valve stem.

Claim 8

The apparatus of claim 6 wherein a portion of the valve stem adjacent the spline drive connection is threadedly engaged with the housing.

Claim 9

The apparatus of claim 1 wherein the valve means includes a housing containing a valve stem, a valve seat, and a solenoid connected with the valve stem.

Claim 10

The apparatus of claim 8 wherein the means for controlling the valve means includes electrical energy means interruptably connected with the solenoid and which is responsive to the temperature monitoring means.

Claim 11

The apparatus of claim 9 wherein the temperature monitoring means comprises thermocouples located adjacent the catalytic heater, which are electrically connected with a surface recorder.

Claim 12

The apparatus of claim 10 including a null balance connected with the thermocouples and adapted to transmit a control signal to the valve control means upon receiving temperature readings outside a predetermined temperature range.

Claim 13

The apparatus of claim 11 wherein the valve control means is responsive to the control signal, transmitted by the null balance and includes a switch means, interposed between the electrical energy means and the solenoid, for controlling the flow of electrical energy from the electrical energy means to the solenoid.

Claim 14

The apparatus of claim 1 including a check valve means, positioned below the valve means, for preventing backflow through the catalytic surface.

Claim 15

In a downhole catalytic wellbore heater system having a catalytic surface extending below well pipe and utilizing a fuel mixture passed from the surface, the improvement comprising: a temperature responsive downhole valve means having a valve seat and valve stem positioned in the well pipe above and adjacent to the downhole catalytiC surface, and wherein said downhole valve means is adapted to regulate the amount of one component of a fuel mixture passing through the valve seat and into contact with the catalytic surface.

Claim 16

In a downhole catalytic wellbore heater system having a catalytic surface extending below well pipe and utilizing a fuel mixture passed from the surface, the improvement comprising: a temperature responsive downhole valve means having a valve seat and valve stem positioned in the well pipe above and adjacent to the downhole catalytiC surface, and wherein said downhole valve means is adapted to regulate the amount of one component of a fuel mixture passing through the valve seat and into contact with the catalytic surface.

Claim 17

The apparatus of claim 14 including means for continuously determining the temperature adjacent the catalytic surface, including means for determining when such temperature is outside a predetermined temperature range, and which is adapted to initiate a control signal upon the occurrence of the temperature falling outside that predetermined range, and means operably connected to the valve means and responsive to the control signal for activating the temperature responsive valve means.

Claim 18

The apparatus of claim 15 wherein the valve activating means includes an electric motor connected with the valve stem.

Claim 19

The apparatus of claim 16 wherein the valve activating means includes a source of electrical energy located at the surface, an electric line connecting the energy source with the electric motor, and switch means positioned on the electric line and responsive to the control signal generated by the temperature limit means.

Claim 20

The apparatus of claim 20 wherein the regulating means comprises a valve stem, a valve seat located adjacent the valve stem, and a motor coupled with the valve stem and wherein a portion of the valve stem is threadably engaged with the housing such that rotation of the valve stem about its longitudinal axis will cause the valve stem to move in a vertical direction.

Claim 21

The apparatus of claim 18 wherein the motor is adapted to run in a forward and a reverse direction and wherein the motor is attached to the valve stem in a manner to allow rotation of the valve stem.

Claim 22

Apparatus for supplying heat to a wellbore having well pipe therein comprising: a catalytic material having flow channels therethrough attached at the lower end of the well pipe; means for flowing one component of a fuel mixture down the well pipe and through the catalytic material; means for flowing the remaining component of the fuel mixture down the wellbore between the wellbore and the well pipe and past the catalytic material; and, flow control means positioned in the well pipe directly above the catalytic material which comprises a housing, a restricted flow channel in said housing, and means in said housing for regulating flow through the restricted flow channel.

Claim 23

Apparatus for supplying heat to a wellbore having well pipe therein comprising: a catalytic material having flow channels therethrough attached at the lower end of the well pipe; means for flowing one component of a fuel mixture down the well pipe and through the catalytic material; means for flowing the remaining component of the fuel mixture down the wellbore between the wellbore and the well pipe and past the catalytic material; and, flow control means positioned in the well pipe directly above the catalytic material which comprises a housing, a restricted flow channel in said housing, and means in said housing for regulating flow through the restricted flow channel.

Claim 24

The apparatus of claim 20 including electrically responsive means for controlling movement of the flow regulating means; electrical energy means electrically connected with the flow regulating means; means for continuously determining the temperature adjacent the catalytic material; means for comparing such temperature with a predetermined range; and means responsive to the comparer means for controlling the electrical energy means so that the flow regulating means is responsive to the temperature adjacent the catalytic material.

Claim 25

The apparatus of claim 21 wherein the temperature determining means includes thermocouples positioned on the catalytic material and in the wellbore below the catalytic material; wherein the restricted flow channel includes a valve seat and the flow regulating means includes a valve stem; wherein the flow regulating means includes an electric motor connected with the valve stem; wherein the temperature comparer includes a null balance; and wherein the controller means includes a switch means responsive to the null balance, and which switch means acts to control the current being supplied the electric motor.

Claim 26

The apparatus of claim 22 wherein the electric motor has the capability to run in both a forward and reverse direction and is attached to the valve stem in a manner to rotate the valve stem in clockwise and counterclockwise directions and wherein a portion of the valve stem is threadedly engaged with the interior wall of said flow control means housing, such that rotation of the valve stem will move the valve stem in a vertical direction.