Engineered Solutions for Landfill Gas Well Field Management

Transcription

1 Engineered Solutions for Landfill Gas Well Field Management December 17, 2013 Brad Peake New Products Manager QED Environmental Systems Inc. Ann Arbor, Michigan - San Leandro, California 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 The information contained within this document may not be published, broadcast, rewritten or otherwise distributed without the prior written authorization from QED.

2 Today s Webinar Outline Challenges with Typical LFG Wellheads and Well Caps Well Caps/Transition Couplings o Traditional Gas Well completions o QED s Stabilizer Well Caps Flow Measurement o o Traditional Flow Measurement QED s Flow Measurement Offering Flow Control o o Traditional Flow Control The Precision Fine Tune Control Valve QED s LFG Wellheads Case Studies (2)

3 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

4 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

5 Problems with Traditional Wellheads Flexible rubber couplings (e.g., Fernco couplings) have very little structural strength to support the weight of the well head and flex hose, 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

6 Problems with Traditional Well Caps

7 Leaking Flexible Coupling

8 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.

9 QED Stabilizer Well Caps Easy access for liquid level measurements faster, safer, no need to shut down (or re-set) 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.

10 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

11 Common LFG Flow Measurement Methods Pitot Tubes are intended to fit a wide range of flow rates, but can easily clog with condensate, mineralization and corrosion, and have poor accuracy at flows under 20 CFM (± 5-10% at best, ± 20% worst) Venturi are also a one size fits all device, but create significant pressure drop at high flows (>12 SCFM) and insufficient pressure drop for reliable measurement at flows under 25 SCFM Orifice Plate sizes can be selected to match changes in flow rates, but changing plates can be time consuming, requires shutting off gas flow and breaking pipe connections, and gas techs can t see the plate size without opening the pipe union

12 Quick-Change Orifice Plate Utilizes proven orifice plate technology for accurate and repeatable flow rates Plates can be swapped out by one person in seconds to achieve desired Differential Pressure 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

13 Flow Control Using Gate Valves Advantages Lower initial cost Widely available Disadvantages Closed 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 Open

14 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.

15 QED Precision Control Valve vs. 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

16 QED s Wellhead Offering Quick-Change Orifice Plate Wellhead Traditional Orifice Plate Wellhead

17 Quick-Change Orifice Plate Wellhead Revolutionary quickchanged 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 Glass fiber reinforced polypropylene components adds strength

18 Quick-Change Orifice Plate Wellheads

19 Precision Wellhead Port Identification Available Vacuum (System) Temperature Low Pressure High Pressure/Applied Vacuum/ Gas Composition Orifice Plate

20 Wellhead System Drawings Quick-Change Orifice Plate Wellhead

21 Low-vacuum Landfill Case Study Low-flow, low-vacuum landfill Waste-to-energy site with Recycling and Composting 63 acres of current waste Gas collection system uses over 70 vertical gas collection wells and 30 horizontal gas collectors QED Wellheads installed on several existing LFG wells to help regulate gas flow

22 Low-vacuum Landfill Case Study Wellhead Comparison Data

23 Low-vacuum Landfill Case Study

24 Low-vacuum Landfill Case Study 3-Well Comparison QED Wells Other Wells

25 Low-vacuum Landfill Case Study 3-Well Comparison Well Data Graphs

26 Low-vacuum Landfill Case Study Trunk Line Comparison

27 Low-vacuum Landfill Case Study Trunk Line Comparison Existing Wells

28 Low-vacuum Landfill Case Study Trunk Line Comparison QED install Well 26 and 27

29 Low-vacuum Landfill Case Study Testimonials The system runs at low vacuum so a small change in the vacuum at a well can cause over-pulling. Gate valves didn t offer adequate flow control and a number of wells required constant attention. LFG Technician The QED wellheads give us better control over gas flows. Landfill Manager

30 Reduced Oxygen Case Study 300 acre site designated for waste disposal Approximately 200 wells on site Landfill installed QED Wellheads on a few existing LFG wells hoping to reduce NSPS exceedances and maximize methane production

31 Reduced Oxygen Case Study Test Wells QED Wells Other Well

32 Reduced Oxygen Case Study Wellhead Comparison Data

33 Reduced Oxygen Case Study Well Data Comparison Before and after QED Wellhead install on Well 54

34 Reduced Oxygen Case Study Well Data Comparison Before and after QED Wellhead install on Well 78

35 Reduced Oxygen Case Study Well Data Comparison Before and after QED Wellhead install on Well 90

36 Reduced Oxygen Case Study Well Data Comparison Comparison of Well 90, before and after QED wellhead installation, to neighboring Well 29, which continues to use Other wellhead.

37 The Value of Improving LFG Gas Flow and Methane Content

38 QED Wellhead Trial Offer Try a QED Wellhead for 60 days at no charge. At the end of the Trial Offer you may purchase the unit or return it to QED.

39 Questions? Brad Peake QED Environmental Systems, Inc. Ann Arbor, MI and San Leandro, CA Toll-free: Direct: