Innovative Wellhead Tools for Landfill
Gas Management
Brad Peake
New Products Manager
QED Environmental Systems Inc.
Ann Arbor, Michigan - San Leandro, California
September 27, 2012
Copyright © QED Environmental Systems, Inc. 2012; all rights reserved. The information contained within this document
may not be published, broadcast, rewritten or otherwise distributed without the prior written authorization from QED.
Today’s Webinar Outline
• Challenges with Typical LFG Wellheads and Well Caps
• Well Caps
o Traditional Gas Well completions
o QED’s Stabilizer Well Caps
• Flow Measurement
o Traditional Flow Measurement
o QED’s Flow Measurement Offering
• Flow Control
o Traditional Flow Control
o The Precision Fine Tune Control Valve™
• QED’s LFG Wellheads
LFG Well Field and GCCS Goals
• Maximize LFG energy content (flow rate and methane
concentration) where gas is utilized
• Avoid NSPS violations for PTO exceedance
• Compliance with LFG emission regulations
• Avoid odor complaints from neighbors
• Reduce time and labor spent for well field management
• Reduce and simplify well field maintenance and repairs
Maximize gas collection efficiency while maintaining
regulatory compliance, all at the lowest possible cost
Traditional LFG Wellheads
• PVC gate valve for flow
control is most common
• A Union orifice plate, Pitot
tube or venturi used for
flow measurement
(calculated from
differential pressure)
• Flexible couplings are
used to connect the well
riser and well head
Problems with Traditional Wellheads
• Flexible rubber couplings (e.g., Fernco® couplings) have
very little structural strength to support well head and
flex hose weight, become brittle, collapse under
vacuum, and can be difficult to seal, all resulting in air
leaks
• Pitot tubes, orifice plates and venturi used for flow
measurement have limitations with accuracy or are
difficult to use, resulting in measurement errors
• Gate valves were designed for controlling liquids, not for
regulating gas flow – small adjustments in valve
opening can result in large changes in applied vacuum
and resultant flow
The Problem withTraditional Well Caps
Leaking Flexible Coupling
Introducing
QED Stabilizer™ Well Caps
• First engineered LFG Well Cap
that aligns and stabilizes the
LFG wellhead minimizing air
leaks and gas release.
• Features a unique support ring
molded directly into the Well Cap
(patent pending) that aligns and
stabilizes the wellhead.
• Takes pressure off the flexible
coupling and the flex hose.
QED Stabilizer™ Well Caps
• Easy access for liquid level
measurements – faster, safer, no need to
shut down the vacuum system.
• Caps are molded in a highly visible,
bright yellow helping identify and protect
the entire well from damage.
• Durable, heavy-walled,
polyethylene construction
makes it ideal for any climate.
QED Stabilizer™ Well Caps
• Designed to work with 6” and 8” diameter wells with 2” or 3”
wellheads
• All models provide ports to accommodate a down well pump.
• Pump fitting kits allow
conversion of gas recovery
caps to dual extraction
Traditional Flow Measurement
Common Flow Measurement Methods for
Landfill Gas Wellheads
• Pitot Tube
• Orifice Plate
• Venturi
New Flow Measurement Method
• Portable Thermal Mass Flow Meter
Pitot Tube
3/16”
Orifice Plate
Venturi
Common Flow Measurement Methods
Pitot Tube
Advantages – variety of sizes and configurations for vertical or horizontal pipes
Disadvantages – tube can clog from moisture and mineralization and give false
readings; poor accuracy for flows under 20 SCFM (± 5-10% at best, ± 20% worst)
Venturi
Advantages – can be used for vertical or horizontal applications; promoted as one-
size-fits-all
Disadvantages – fixed size = significant pressure drop (>10” WC) over 90 SCFM;
insufficient pressure drop for reliable measurement at flows under 20 SCFM
Orifice Plate
Advantages – proven technology with accurate results, ability to change plate
sizes to achieve desired pressure differential with changing flow rates
Disadvantages – changing plates is cumbersome, requires shutting off gas flow
and breaking pipe connection, often takes two people; operator can’t even see if a
plate is installed or what size it is without opening the union assembly
Introducing
• Utilizes proven orifice plate technology
for accurate and repeatable flow rates
• Plates can be swapped out by one
person in seconds to achieve desired
∆P with changes in gas flow rate
• No time wasted shutting down the
control valve, breaking pipe
connections or rebalancing the well
• Accessible plate housing allows for
easy confirmation of plate size and
placement reducing reporting errors
• Durable PVC construction with
stainless steel orifice plates
Quick-Change™ Orifice Plate
Quick-Change™ Orifice Plate
QED Quick-Change Orifice Plate can be changed in less than
60 seconds by one person without interrupting LFG flow,
saving as much as 1 hour of field labor over traditional union
orifice plate systems, reducing operating expenses
Precision Flow Meter™
• Precision Flow Meter is an extremely accurate portable
thermal mass flow meter.
• Insertion-style Meter reads directly in SCFM, not a
calculated value.
• Measures and logs gas flows through existing ports in
headers 1” and larger.
• Patented self-calibration check.
Traditional Flow Control
Flow Control Using Gate Valves
Advantages
• Lower initial cost
• Widely available
Disadvantages
• Non-rising stem - operator can’t observe valve opening position
• Plastic threads can strip easily, plastic handle breaks off with age
• Seals fail, dirt and grit get into threads and gate track, and extreme
cold and heat all make valve difficult or impossible to adjust or
cause the valve stem to break when excessive force is applied
• Fully open in 3-4 turns out of 10 - flow adjustment isn’t linear
and can be difficult to regulate, especially at low flow rates
Closed Open
Traditional Gate Valve
Introducing
Precision Fine Tune
Control Valve ™
Precision Fine Tune Control Valve™
• Patented flow-tuned valve design provides precise, linear
control of flow from fully closed to maximum flow.
• Rising stem design and highly visible metered scale allows
easy observation of valve position setting, making it easy to
quickly return to the exact setting if the valve must be closed.
• Rugged stainless steel valve stem and
handle makes it durable in harsh
outdoor environments.
Fine Tune Control Valve™
QED Precision Control Valvevs. PVC Gate Valve
• PVC gate valve offers very little control, with maximum
flow achieved at just four turns
• QED Precision Valve has highest resolution at lower
flows (under 25 SCFM), with nearly linear flow control
across entire range of valve opening
Precision Valve Case Study
• South Texas landfill site
• Installed three Precision Fine Tune Control Valves on
existing LFG well heads in July & Nov. 2011
• Following graphs show LFG flow rate and gas quality
data for several months before, and a few months
following, Precision Valve installation
Case StudySouth Texas Landfill
Well 54
Case StudySouth Texas Landfill
Well 78
Case StudySouth Texas Landfill
Well 90
Case StudySouth Texas Landfill
Well 29
Neighbor to Well 90
Control with gate valve
The Value of Improving LFG Gas Flow and Methane Content
QED’s Wellheads
QED’s Wellhead Offering
Quick-Change™
Orifice Plate WellheadTraditional
Orifice Plate Wellhead
Flow Meter™ Wellhead
Quick-Change™ Orifice Plate Wellhead
• Revolutionary quick-
changed orifice plate
system (patent pending) for
accurate flow measurement
• Precision Fine-Tune Valve
for precise flow control over
a broad flow range
• New emphasis on
increasing the visibility of
the wellhead includes
diamond reflector tape
Quick-Change™ Orifice Plate Wellhead
• Available in 2” and
3” pipe sizes
• Brass barbs or
quick-connects for
flow measurement
and LFG sampling
• Orifice plate kits
contain a range of
plate sizes to match
flow range of valve
Flow Meter™ Wellhead
• For those looking for cutting-edge flow measurement
technology and precise flow control.
Traditional Orifice Plate Wellhead
• For those looking for sensitive flow adjustment capability
and a lower cost assembly.
Wellhead System Drawings
Quick-Change™ Orifice Plate Wellhead
Try a QED Wellhead for 60 days at no charge.
At the end of the Trial Offer you maypurchase the unit or return it to QED.
Free Wellhead Trial Offer
Questions?
Brad PeakeQED Environmental Systems, Inc.
Ann Arbor, MI and San Leandro, CAwww.qedenv.com
E-mail: [email protected]: 800-624-2026Direct: 734-995-2547