Devices and methods for landfill gas well monitoring and control

• US 9,062,536 B2
• Filed: 03/11/2013
• Issued: 06/23/2015
• Est. Priority Date: 01/02/2013
• Status: Active Grant

• Current Assignee: Q.E.D. Environmental Systems, Inc. (Graco Incorporated)
• Original Assignee: Graco Minnesota Incorporated (Graco Incorporated)
• Inventors: Fischer, David A., Mioduszewski, David
• Primary Examiner(s): Neuder, William P
• Application Number:
  US13/794,242
• Publication Number:
  US 20140182846A1
• Time in Patent Office: 834 Days
• US Class Current: 1/1
• CPC Class Codes: B09B 1/006 Shafts or wells in waste dumps
• CPC Class Codes: B09B 3/80 involving an extraction step
• CPC Class Codes: E21B 34/025 Chokes or valves in wellheads and sub-sea wellheads for variably regulating fluid flow
• 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
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: E21B 47/00 Survey of boreholes or wells monitoring pressure or flow of drilling fluid E21B21/08
• CPC Class Codes: H04B 1/3833 Hand-held transceivers
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

A landfill well control system includes a mobile hand-held device provided with a software monitoring application including a table having data related to determination of a desired methane gas output flow rate. A landfill gas (LFG) wellhead gas control valve includes: an electronically controlled, powered flow control device actuator; a flow measurement element producing differential pressures proportional to a gas flow rate; a pressure sensor/transducer; and a microprocessor having control logic capability and the ability to communicate via a local wireless signal to the mobile hand-held device. The powered flow control device actuator using data from the table of the mobile hand-held device or remotely stored data provides automatic valve positioning.

Claims

1. A landfill well control system for use in connection with landfill well having a wellhead, wherein landfill gas (LFG) is produced within a wellbore of the landfill well and a rate of flow of the LFG out through the wellhead needs to be monitored and periodically adjusted to maintain a desired rate of flow of the LFG out through the wellhead, the system comprising:

an adjustable LFG flow control valve having a valve element, the adjustable LFG flow control valve being attached to the wellhead and dedicated to the wellhead, and further being settable at a plurality of different specified positions;

a hand holdable device having a processor with a software monitoring application running thereon, the software monitoring application including a table having stored data used by the processor in computing a desired landfill gas output flow rate, the stored data including information which maps a relationship of a specific position of the valve element within the flow control valve with an indicated differential pressure; and

the hand holdable device further configured to process received data relating to the LFG flow to provide a specific, recommended control valve position adjustment for the valve element intended to achieve a specific system goal relating to the LFG being withdrawn through the adjustable LFG flow control valve.

2. The landfill well control system of claim 1, wherein:

the hand holdable device comprises a wireless communications device, and wherein the flow control device of the LFG wellhead gas control valve comprises an electronically controlled flow control device; and

further including a flow measurement element provided at the adjustable LFG flow control valve producing differential pressures proportional to the LFG flow rate, the differential pressures converted to signals communicated to the wireless communications device.

3. The landfill well control system of claim 1, further including a pressure sensor/transducer provided at the adjustable LFG flow control valve.

4. The landfill well control system of claim 1, further including a microprocessor provided at the adjustable LFG flow control valve having control logic capability and a wireless transmitter to communicate via a local wireless signal to the hand holdable device.

5. The landfill well control system of claim 1, wherein the hand-holdable device comprises a wireless device configured to communicate wirelessly with the adjustable LFG flow control valve.

6. The landfill well control system of claim 1, further including:

a pressure drop measurement device configured to be removably coupled to a pressure gradient producing orifice assembly associated with the wellhead assembly.

7. The landfill well control system of claim 1, further including indexing marks created on the adjustable LFG flow control valve identifying a plurality of corresponding valve element positions for the valve element within the flow control valve, the plurality of valve element positions enabling a user to set the adjustable LFG flow control valve to a desired position that corresponds to a desired gas flow rate and for a set of well operating parameters including temperature, barometric pressure and humidity.

8. The landfill well control system of claim 1, wherein the hand holdable device comprises a device having wireless communications capability, and further including a mass flow rate device to electronically send a wireless mass flow rate measurement signal of the landfill gas to the hand holdable device.

9. A landfill well control system for controlling a flow of landfill gas (LFG) through a wellhead associated with a landfill well at a landfill, the system comprising:

a mobile hand-held device having a wireless communications subsystem and a processor, the processor running a software monitoring application including a table, the table having data related to determination of a desired landfill gas output flow rate of a landfill gas;

an adjustable LFG flow control valve associated with the wellhead and having a valve element settable to a selected one of a plurality of independent positions to control the flow of LFG through the wellhead;

a landfill gas (LFG) wellhead measurement device including;

an electronically controlled, powered flow control device actuator for controlling a setting of the adjustable LFG flow control valve;

a flow measurement element producing differential pressures proportional to a landfill gas flow rate;

a pressure sensor/transducer; and

a microprocessor having control logic capability for controlling the electronically controlled, powered flow control device actuator, and further being configured to communicate via a short range, wireless signal with the wireless communications subsystem of the mobile hand-held device, and to use information supplied wirelessly from the mobile hand-held device to control the electronically controlled, powered flow control device actuator to adjust a setting of the adjustable LFG flow control valve to achieve a specific system goal.

10. The landfill well control system of claim 9, wherein the flow measurement element further includes an internal pressure transducer, a micro-controller and a wireless communications device including communication protocols using digital radios, the flow measurement element being connected to the LFG well head.

11. The landfill well control system of claim 9, wherein the mobile hand-held device includes a program providing for input of a pressure drop device specification including an orifice size of an orifice assembly associated with the adjustable LFG flow control valve.

12. The landfill well control system of claim 9, wherein the mobile hand-held device makes use of a flow control device index position indicated by a set of indexing marks located on the adjustable LFG wellhead flow control valve, the index position being used by the mobile-held device in determining the LFG flow rate.

13. The landfill well control system of claim 9, wherein the mobile hand-held device includes LFG data including LFG well head vacuum and pressure, LFG gas quality data, LFG gas temperature, site and ambient data readings such as barometric pressure, air temperature, and/or a geospatial location of an LFG well head.

14. A landfill well control system for monitoring and controlling a flow of landfill gas (LFG) through a wellhead of a landfill well at a landfill, the system comprising:

a wireless device provided with a processor running a software monitoring application including a table having data related to determination of a desired landfill gas output flow rate;

a combination unit including configured to be attached to the wellhead, the combination unit including;

a measurement component for making a measurement of at least one of LFG flow rate or a differential pressure;

an adjustable LFG flow control valve having a valve element which is adjustable to a plurality of positions;

an electronically controlled, powered flow control device actuator operating in communication with the adjustable LFG flow control valve, to control a setting of the adjustable LFG flow control valve in response to signals from the wireless device to achieve a specific system goal, the combination unit being in wireless communication with the wireless device; and

a data storage device operably associated with the combination unit, and being in communication with the wireless device, the data storage device retaining historical data of the landfill gas flow rate accessible in the data storage device at the same time new data is acquired.

15. The landfill well control system of claim 14, wherein the wireless device includes a mobile hand-held wireless device being configured to communicate control target settings and readings via local wireless signals to the combination unit for use in adjusting the adjustable LFG flow control valve.

16. The landfill well control system of claim 14, further including a keypad and a digital display operably associated with the combination unit, the keypad used to enter desired control target settings of the adjustable LFG flow control valve.

17. The landfill well control system of claim 14, further including an oxygen sensor monitored by an operator to maintain a landfill well oxygen level below a desired set-point.

18. A method for controlling an output flow rate of a landfill gas flowing through a wellhead at a landfill well, the method comprising:

using a mobile hand-holdable device having a processor running a software application to process LFG measurement data to help determine a recommended flow control valve position of an adjustable LFG flow control valve associated with the wellhead in real time, to thus adjust the output flow rate of the landfill gas in real time;

using a hand-holdable measurement subsystem secured to the wellhead to obtain a measurement associated with a flow of the LFG through the wellhead, and wirelessly transmitting information relating to the obtained measurement directly to the mobile hand-holdable device via a short range wireless signal link; and

using the mobile hand-holdable device to process the obtained measurement data and to determine a recommended flow control valve position setting to for use in adjusting a setting of the adjustable LFG flow control valve.

19. The method of claim 18, further comprising repeating the storing step for multiple landfill gas well heads of a common landfill site, including obtaining historical readings from individual ones of the multiple landfill gas well heads and generating multiple recommended flow control valve positions for a corresponding plurality of adjustable LFG flow control valves.

20. The method of claim 18, further comprising:

1) using the processor to periodically, including from between 1-12 times daily, control the gas flow control valve to perform repeated, stepwise openings and closings of the adjustable LFG flow control valve;

2) taking new measurements of a landfill gas flow rate as the adjustable LFG flow control valve is repeatedly adjusted by the processor; and

3) computing a ratio of an additional landfill gas flow rate gained divided by a change in a vacuum level applied to the well head assembly.