Innovative Wellhead Tools for Landfill Gas Management · LFG wellhead minimizing air leaks and gas...

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may not be published, broadcast, rewritten or otherwise distributed without the prior written authorization from QED.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: info@qedenv.comToll-free: 800-624-2026Direct: 734-995-2547