Method for wellhead control

• US 5,335,730 A
• Filed: 02/08/1993
• Issued: 08/09/1994
• Est. Priority Date: 09/03/1991
• Status: Expired due to Fees

• Current Assignee: Heman C. Cotham III
• Original Assignee: Heman C. Cotham III
• Inventors: Cotham, Heman C. III
• Primary Examiner(s): Britts, Ramon S.
• Assistant Examiner(s): TSAY, FRANK
• Application Number:
  US08/014,798
• Time in Patent Office: 547 Days
• Field of Search: 166/50, 166/53, 166/250, 166/369, 166/373, 166/374, 175/5
• US Class Current: 166/374
• CPC Class Codes: E21B 34/16 Control means therefor being outside the borehole control systems for submerged well heads E21B33/0355
• CPC Class Codes: E21B 43/12 Methods or apparatus for controlling the flow of the obtained fluid to or in wells E21B43/25 takes precedence; valve arrangements E21B34/00

Abstract

A method is disclosed which, in one aspect, includes providing power to a system for controlling a wellhead from a self-contained stand-alone power source, controlling the delivery of power to the system with a control unit (in one aspect a microprocessor control unit), using various valves to control flow of fluids from within the well and from the well in one or more flowlines, and monitoring various parameters both in the flowlines and in and around the well and the wellhead, including but not limited to fluid pressures and emergency conditions, and shutting-in the well in response to certain signals generated by the system based on the monitoring.

Claims

1. A method for controlling a wellhead on a well, the well extending from beneath the earth to a surface thereof, the wellhead including a plurality of valves for controlling flow of fluids in flowlines to and from the well, each fluid having a pressure level in a flowline, the plurality of valves including at least a downhole valve and a surface valve, the downhole valve controlling flow of fluid from within the well to the surface and the surface valve controlling flow of fluid from the well to a location, the method comprising the step of:

producing power from an integral stand-alone power apparatus for producing electric power adjacent the well;

delivering power produced by the power apparatus to a control unit and to pumping apparatus;

operating the pumping apparatus to pump operating fluid to the downhole valve to operate the downhole valve and pumping operating fluid to the surface valve to operate the surface valve; and

controlling the pumping and the valves with the control unit.

2. The method of claim 1 wherein the downhole valve is disposed in a well flowline, and the surface valve is disposed in a surface flowline;

and the method further comprising the steps of;

monitoring pressure of fluids and the flowlines and sensing a pressure level in each flowline;

producing an alarm signal if pressure is not within a pre-set acceptable range and transmitting an alarm signal to the control unit; and

shutting-in the well in response to the alarm signal by operating the downhole valve and the surface valve to close off their respective flowlines to fluid flow.

3. The method of claim 2 wherein the downhole valve is operated first and then the surface valve is operated.

4. The method of claim 3 wherein pressure of operating fluid operating the surface valve is less than pressure of operating fluid operating the downhole valve.

5. The method of claim 4 wherein the surface flowline also has a wing valve therein in addition to the surface valve, the wing valve for closing off flow therein, and the method further comprising the step of:

operating the wing valve prior to operating the surface valve.

6. The method of claim 1 wherein the operating fluid is an hydraulic fluid.

7. The method of claim 5 wherein the wing valve and the surface valve are solenoid operated valves operated by solenoids;

and the method further comprising the step of;

controlling the solenoids and operating them with the control unit.

8. The method of claim 1 wherein the control unit and power apparatus are within a housing, the housing having interior space within which are the control unit and power apparatus, the method including:

ventilating the housing.

9. The method of claim 8 wherein the control unit is a microprocessor control unit.

10. The method of claim 1 wherein the power apparatus is a solar power array and the method includes:

storing power produced by the solar power array in at least one storage battery, the control unit interconnected with the at least one storage battery for controlling delivery of power to the valves and to the pumping apparatus.

11. The method of claim 10 wherein the pumping apparatus includes a motor and a pump, the motor connected to the pump for operating the pump, the method including:

controlling operating of the motor with the control unit.

12. The method of claim 11 including:

controlling voltage of the electric power with a voltage controller.

13. The method of claim 11 wherein the power apparatus produces electrical power at a voltage and at an amperage and the method includes:

sensing the voltage of the electrical power and the amperage of the electrical power;

producing signals indicative of sensed voltage and sensed amperage;

transmitting the signals to the control unit;

analyzing the signals and determining whether the voltage and amperage are within an acceptable range;

producing an alarm signal if voltage or amperage is not within the acceptable range; and

shutting-in the well in response to the alarm signal.

14. The method of claim 1 including:

delivering power to the control unit at an amperage less than 100 milliamps.

15. The method of claim 1 including:

sensing at the wellhead an emergency condition;

producing an emergency signal in response to the emergency condition;

transmitting the emergency signal to a location remote from the wellhead; and

receiving the emergency signal at the remote location and, in response thereto, sending an actuation signal from the remote location to the control unit to operate the valves to shut-in the well.

16. A method for controlling a wellhead on a well, the well extending from beneath the earth to a surface thereof, the wellhead including a plurality of valves for controlling flow of fluids in flowlines to and from the well, the plurality of valves including at least a downhole valve and a surface valve, the downhole valve disposed in a downhole flowline from within the well to the surface and controlling flow of fluid therein and the surface valve disposed in a surface flowline from the well to a location and the surface valve controlling the flow of fluid therein, the method comprising the steps of:

producing power from an integral stand-alone solar power array power apparatus for producing electric power adjacent the well;

delivering power produced by the power apparatus to a control unit and to pumping apparatus;

operating the pumping apparatus to pump operating fluid to the downhole valve to operate the downhole valve and pumping operating fluid to the surface valve to operate the surface valve;

controlling the pumping apparatus and the valves with the control unit;

monitoring pressure of fluid in the flowlines and sensing a pressure level therein;

producing a pressure alarm signal if pressure is not within a preset acceptable range and transmitting the pressure alarm signal to the control unit;

shutting-in the well in response to the pressure alarm signal by operating the downhole valve and the surface valve to close off their respective flowlines to fluid flow;

storing power produced by the solar power array in at least one storage battery, the control unit interconnected with the at least one storage battery for controlling delivery of power to the valves and to the pumping apparatus;

sensing voltage of the electrical power and amperage of the electrical power;

producing power signals indicative of sensed voltage and sensed amperage;

transmitting the power signals to the control unit;

producing a power alarm signal if voltage or amperage is not within an acceptable range;

shutting-in the well in response to the power alarm signal;

monitoring at the wellhead for an emergency condition;

producing an emergency signal if an emergency condition is monitored; and

shutting-in the well in response to the emergency signal.