Well control system

A system for controlling the flow from a gas lift petroleum production well in which a borehole penetrates at least two spacially separated geological production zones and includes a casing extending from a wellhead to line the borehole and extend into both of said spacially separated production zones and at least two strings of tubing extending in parallel along the interior of the casing from the wellhead and wherein the first string of tubing extends into the region of the first of said spacially separated production zones and the second string of tubing extends into the region of the second of said production zones, said system comprising:

• a gas lift valve connected in each one of said strings of tubing with a first valve being associated with said first production zone and a second valve being associated with said second production zone;
• a single source of pressurized gas connected to the casing at the wellhead to provide a source of lift gas;
• and
• means for independently varying the size of the flow control aperture within each of said first and second gas lift valves to control the production of fluids from each of said first and second production zones, said means including,
• means for monitoring the production flow from each of said strings of tubing at the surface;
• and
• means responsive to the volume of production flow from each of said strings of tubing for varying the size of the control aperture in each of said first and second gas lift valves to optimize the flow of production flow through each tubing string to the surface.

A method for controlling the flow from a gas lift petroleum production well in which a borehole penetrates at least two spacially separated geological production zones and includes providing a casing extending from a wellhead to line the borehole and extend into both of said spacially separated production zones and at least two strings of tubing extending in parallel along the interior of the casing from the wellhead and wherein the first string of tubing extends into the region of a first of said spacially separated production zones and the second string of tubing extends into the region of the second of said production zones, said method comprising:

• providing a gas lift valve connected in each one of said strings of tubing with a first valve being associated with said first production zone and a second valve being associated with said second production zone;
• providing a single source of pressurized gas connected to the casing at the wellhead to provide a source of lift gas;
• and
• independently varying the size of the flow control aperture within each of said first and second gas lift valves to control the production of well fluids from each of said first and second production zones.

A method for controlling the flow from a gas lift petroleum production well in which a borehole penetrates at least two spacially separated geological production zones and includes providing a casing extending from a wellhead to line the borehole and extend into both of said spacially separated production zones and at least two strings of tubing extending in parallel along the interior of the casing from the wellhead and wherein the first string of tubing extends into the region of a first of said spacially separated production zones and the second string of tubing extends into the region of the second of said production zones, said method comprising:

• providing a gas lift valve connected in each one of said strings of tubing with a first valve being associated with said first production zone and a second valve being associated with said second production zone;
• providing a single source of pressurized gas connected to the casing at the wellhead to provide a source of lift gas;
• and
• independently varying the size of the flow control aperture within each of said first and second gas lift valves to control the production of well fluids from each of said first and second production zones, said steps including:
• monitoring the production flow from each of said strings of tubing at the surface;
• and
• varying the size of the control aperture in each of said first and second gas lift valves in response to the volume of production flow from each of said strings of tubing to optimize the flow of production flow through each tubing string to the surface.

A system for controlling the flow from a gas lift petroleum production well which includes a casing extending from a wellhead to line the borehole and extend into a production zone and a string of tubing extending along the interior of the casing from the wellhead into the region of said production zone, said system comprising:

• a gas lift valve connected in said string of tubing and being located in the region of said production zone;
• a source of pressurized gas connected to the casing at the wellhead to provide a source of lift gas;
• means for monitoring the flow of production flow from said tubing at the surface;
• and
• means responsive to the rate of production flow from the tubing for varying the size of the flow control aperture within said gas lift valve to control the production of well fluids from said production zone while minimizing the fluctuations in said production flow rate.

A method for controlling the flow from a gas lift petroleum production well which includes a casing extending from a wellhead to line the borehole and extend into a production zone and a string of tubing extending along the interior of the casing from the wellhead into the region of said production zone, said method comprising:

• providing a gas lift valve connected in said string of tubing and being located in the region of said production zone;
• providing a single source of pressurized gas connected to the casing at the wellhead to provide a source of lift gas;
• and
• monitoring the flow of production flow from said tubing at the surface;
• varying the size of the flow control aperture within said gas lift valve in response to the rate of production flow from the tubing to control the production of well fluids from said string of tubing and minimize the fluctuations in said production flow rate.

In a system for monitoring downhole variable parameters within a petroleum production well, comprising:

• a control unit located at the surface for producing control signals and for receiving signals indicative of monitored parameter values;
• a plurality of sensors located downhole for generating a signal related to the value of a variable parameter;
• a cable extending down said well for connecting all of said plurality of sensors to said control unit at the surface;
• an address control switch associated with each one of said plurality of sensors and connected to said cable, each one of said address control switches having a unique address code upon receipt of which it will connect its associated sensor to said cable for electrical communication with said control unit;
• and
• an address code generator located within said control unit and connected to said cable for selectively generating control signals containing the address code associated with the address control switch of the particular downhole sensor for the downhole parameter to be monitored at the surface.

A system for monitoring and controlling downhole parameters within a petroleum production well comprising:

• a first electrical component located downhole which requires a relatively low value of operating voltage;
• a second electrical component located downhole which requires periodic pulses of a relatively high value of operating voltage;
• a single cable extending from the surface for supplying operating voltage to both said first and second electrical components;
• first circuit means connected between said cable and said first electrical component for allowing a said relatively low value of voltage to pass and supply operating power to said component and responsive to a value of voltage on said cable in excess of a threshold value for electrically disconnecting said first component from said cable and responsive to the value of voltage on said cable decreasing to zero for reconnecting said first component to said cable;
• and
• second circuit means connected between said cable and said second electrical component for disconnecting said component from said cable to prevent said component from electrically loading the power supply circuit and responsive to a value of voltage on said cable in excess of a threshold value for electrically connecting said second component to said cable to allow said voltage to pass and operate said component and responsive to the value of voltage on said cable decreasing to zero for disconnecting said second component to said cable.

A system for monitoring and controlling downhole parameters within a petroleum production well comprising:

• a casing extending from a wellhead to line the borehole and extend into a production zone;
• a string of tubing extending along the interior of the casing from the wellhead into the region of said production zone;
• a valve connected in said string of tubing and being located in the region of said production zone;
• means for varying the size of the flow control aperture within said valve to control the flow of fluids from the casing into the tubing;
• means connected to said valve for continuously generating a signal indicative of the current size of the flow control aperture;
• a control unit located at the surface for generating control signals and for monitoring the size of the flow control aperture within said valve;
• a control cable extending down said casing and connected from said control unit to said valve for coupling control signals from said control unit to said valve to vary the size of the flow control aperture thereof and to couple said size indicative signals from said signal generating means to said control unit for monitoring thereof.

A system for monitoring and controlling downhole parameters within a petroleum production well comprising:

• a casing extending from a wellhead to line the borehole and extend into a production zone;
• a string of tubing extending along the interior of the casing from the wellhead into the region of said production zone;
• a valve connected in said string of tubing and being located in the region of said production zone;
• means for varying the size of the flow control aperture within said valve to control the flow of fluids from the casing into the tubing;
• means connected to said valve for generating a signal indicative of the size of the flow control aperture;
• a control unit located at the surface for generating control signals and for monitoring the size of the flow control aperture within said valve and different variable parameter values;
• a control cable extending down said casing and connected from said control unit to said valve for coupling control signals from said control unit to said valve to vary the size of the flow control aperture thereof and to couple said size indicative signals from said signal generating means to said control unit for monitoring thereof;
• a sensor for generating a signal indicative of pressure located in the region of said valve, said sensor being connected to said control cable for receiving a low voltage power supply signal from said control unit and for sending said pressure indicative signal from said sensor to said control unit;
• and
• a first voltage sensitive switch positioned between said control cable and said sensor for electrically connecting the low voltage power supply signal from said control unit to said sensor and responsive to a relatively higher voltage control signal for varying the size of the flow control aperture of said valve for electrically disconnecting said sensor from said cable to protect the circuitry of said sensor from said higher voltage.

A system for monitoring and controlling downhole parameters within a petroleum production well comprising:

• a casing extending from a wellhead to line the borehole and extend into a production zone;
• a string of tubing extending along the interior of the casing from the wellhead into the region of said production zone;
• a valve connected in said string of tubing and being located in the region of said production zone;
• means for varying the size of the flow control aperture within said valve to control the flow of fluids from the casing into the tubing;
• means connected to said valve for generating a signal indicative of the size of the flow control aperture;
• a control unit located at the surface for generating control signals and for monitoring the size of the flow control aperture within said valve and different variable parameter values;
• a control cable extending down said casing and connected from said control unit to said valve for coupling control signals from said control unit to said valve to vary the size of the flow control aperture thereof and to couple said size indicative signals from said signal generating means to said control unit for monitoring thereof;
• a sensor for generating a signal indicative of pressure located in the region of said valve, said sensor being connected to said control cable for receiving a low voltage power supply signal from said control unit and for sending said pressure indicative signal from said sensor to said control unit;
• means connected between said flow control aperture size indicative signal generating means and said cable for producing a signal within a first range of frequencies;
• and
• means connected between said sensor and said cable for producing a signal within a second range of frequencies which excludes frequencies within said first range.

A system for monitoring and controlling downhole parameters within a petroleum production well comprising:

• a casing extending from a wellhead to line the borehole and extend into a production zone;
• a string of tubing extending along the interior of the casing from the wellhead into the region of said production zone;
• a valve connected in said string of tubing and being located in the region of said production zone;
• means for varying the size of the flow control aperture within said valve to control the flow of fluids from the casing into the tubing;
• means connected to said valve for generating a signal indicative of the size of the flow control aperture;
• a control unit located at the surface for generating control signals and for monitoring the size of the flow control aperture within said valve and different variable parameter values;
• a control cable extending down said casing and connected from said control unit to said valve for coupling control signals from said control unit to said valve to vary the size of the flow control aperture thereof and to couple said size indicative signals from said signal generating means to said control unit for monitoring thereof;
• a plurality of sensors for generating signals indicative of associated parameter values, each of said sensors being connected to said control cable for receiving a low voltage power supply signal from said control unit and for sending a parameter value indicative signal to said control unit;
• an address control switch associated with each one of said plurality of sensors and connected between said sensors and said cable, each of said address control switches having a unique address code upon receipt of which it will connect its associated sensor to said cable for electrical communication with said control unit;
• and
• an address code generator located within said control unit and connected to said cable for selectively generating control signals containing the address code associated with the address control switch of the particular sensor for the parameter to be monitored by the control unit.