Tag Archives: Oil & Gas Industry

Part 2: Biogas Mass Flow Measurement–The Challenge

In my previous posts, I shared the focus on the growing need for renewable energy sources in the United States, with biogas becoming a hot commodity. Common sources include harnessing biogas from landfills, as well as digester gas produced at wastewater treatment plants.  One of the major flow measurement challenges in biogas applications is the fact that the composition of biogas varies depending on the source.  Many thermal flow companies have entered this renewable energy market, but few have been able to solve this challenge of adjusting for changing gas composition. This is the achilles heal for most thermal companies. How can the flow meter automatically adjust for changing gas compositions? The answer is, it can’t. It needs to be sent back to the factory for recalibration.

Varying Composition of Biogas
Biogas typically contains about 55-65 percent methane, 30-35 percent carbon dioxide and some hydrogen, nitrogen and other impurities. However, a representative compositional analysis (in volumetric percentage), shown in Table 1, shows the wide ranges in methane composition between 50-75 percent and carbon dioxide between 25-50 percent. This represents how the biogas composition can change with time and changing conditions in the landfill or digester tank. Such variable composition makes biogas very difficult to accurately measure. Most flow meters are calibrated for one specific gas mix composition, which means they cannot provide accurate mass flow meter readings if the composition changes without sending the meter back to the factory for recalibration.

Table 1 : Typical Compositional Changes in Biogas

The Problem: How to measure biogas and manage variable composition
Since the biogas composition is critical to its energy producing value, facilities need to assess the best flow meter measurement technology to manage the compositional changes in biogas. Many companies with varying technologies are interested in measuring the biogas as it leaves the landfill or digester tank, but this is a challenging application for many reasons. These include:

  • Varying gas compositions (see Table 1) make accurate measurements difficult because most meters are calibrated for one gas or mixture; when the composition changes, the flow measurements are no longer accurate and the meter must be recalibrated.
  • Low pressure makes differential pressure  devices like orifice plates unsuitable since they require a fairly large differential pressure to operate.
  • Biogas is often very dirty, with a high moisture and particulate content that can clog up devices like annubars and orifice plates and gum up turbine meters and similar instruments that have moving parts.

In Part 3 of this biogas measurement series, I’ll share how advancements in thermal flow meter technology have actually not only made composition management possible, but highly accurate as well. While I go into more detail in my white paper, Precise Biogas Flow Measurement, I can tell you that few flow meter systems are available on the market today that can account for variable biogas composition.

How have you solved the problem a measureing varying biogas compositions at your facility?

If gas composition changes, field-adjust to maintain flow meter accuracy?

Changes in gas composition cut into productivity in the field, exactly when you need accuracy in flow meter measurement the most. But what if you could retain that precision, even when those changes occur? Now you can do just that with qMix Software.  If your gas composition changes over time, you can now quickly field-adjust the QuadraTherm thermal mass flow meter. You avoid the expense of sending the instrument back to the factory for recalibration by reprogramming it in the field to assure optimum accuracy.

We’re committed to driving innovation here at Sierra, and our qMix Software plays a critical role in our flow meter solutions for the biogas and oil & gas industries. No more sending your air mass flow meter back to the factory for gas recalibration every time your gas changes. Talk about a productivity boost!

Benefits of Changing Gas Mixtures in the Field

qMix Flow Meter SoftwareTraditionally, thermal mass flow meters are calibrated using the exact gas mixture they are intended to measure, or a surrogate mixture with very similar properties. In many industrial applications, like biogas measurement, the gas composition changes from the original calibration. When changes in gas composition occur in the field, the accuracy of the flow meter is adversely affected.

In the past, the only way to correct for a change in gas composition was to return the meter to the factory for gas recalibration. qMix provides a dynamic solution to this problem by allowing end users to manage gas composition changes in the field right from the Smart Interface Program (SIP) provided free with every instrument.

Watch the video to find out more about qMix functionality.

Through an easy-to-use software interface, qMix allows you to:

  • Field-adjust and maintain flow meter accuracy if gas composition changes
  • Avoid costly recalibration; once qMix has been installed, no need to send unit back to the factory if gas composition changes
  • Create and upload unlimited gas mixtures onto one meter-free of charge
  • Save custom gas mixtures onto your personal “My Gases Database” for later use
  • Benefit from Sierra’s proprietary, ever-improving “Gas Database” to download more accurate gases

The qMix software package ships with every QuadraTherm 640i/780i on a beta trial basis as part of each meter’s SIP.


Part 3: Biogas Flow Meter Measurement-The Solution

In recent weeks, I’ve shared some exciting advancements in the biogas industry in regards to renewable energy management. From harnessing biogas energy from landfills to the digester gas produced at wastewater treatment plants, one thing is paramount: Adjusting for changing gas composition is critical to obtaining accurate flow meter measurement for optimal biogas energy collection.  Many flow meter companies want to play in this growing market, but few can solve the inherent problem: How can the flow meter automatically adjust for changing gas compositions without recalibration? In this final biogas post, I’ll share how Sierra’s innovative flow meter design has revolutionized the biogas industry, making the need for constant recalibration a thing of the past—thanks to a design that maximizes four sensors instead of two.

The Solution: Flow Meter Technology for Changing Compositions

Sierra’s four-sensor QuadraTherm technology has moved thermal insertion flow meter technology into a realm of unprecedented accuracy. Readings of +/-0.75% of reading are now possible as opposed to the 2.0% readings of older thermal technologies.

QuadraTherm Thermal Flow Meter

Along with this new 4-sensor technology, traditional analog measurement circuits, like the Wheatstone bridge, have been superseded by more powerful, hyper-fast microprocessors that run comprehensive flow-measurement algorithms to compute mass flow. This proprietary algorithm set serves as the “brain” of the mass flow meter, using inputs from the 4 sensors, to solve the first law of thermodynamics for the sensor in the biogas flow stream, allowing precise calculation of heat convected away by biogas mass flow; providing accurate mass flow measurements in a fraction of a second. This algorithm allows management of gas composition because now recalibration is not required every time the gas changes.

Powerful Flow Meter Combination

By combining four-sensor technology with this algorithm set, the meter has the capability to change gas and compositions without losing accuracy. This new technology creates many benefits:

  • The meter can hold up to four user customizable gas mixtures onboard and store biogas composition in a proprietary gas library, easily accessed through user software.
  • Engineers and operators have access to this gas library, which contains all the gas properties needed to make algorithmic gas mass flow rate calculations.

Once sampling has determined the biogas composition, operators can use a simple software tool to create and name a proprietary biogas mixture. This allows operators and engineers to use just one meter, with one calibration for varying gas compositions, offering a major cost savings compared to continuous sampling devices.

Four-sensor thermal technology: Highly adaptable
The 4-sensor quadratherm mass flow meter pictured in  meets the criteria for successful biogas measurement by managing changes in:

  • Gas composition
  • Gas mass flow rate
  • Gas temperature
  • Gas pressure
  • Outside temperature
  • Pipe conditions (size and roughness)
  • Flow profile

These changing conditions can all be managed with accurate readings without sending the flow meter back to the factory for recalibration, reducing downtime and saving money. Traditional two-sensor thermal flow meters need to be sent back to the factory for recalibration each time the gas composition changes or the application specification changes. This means that during the lifetime of the product, thousands of dollars will be saved in calibration costs, shut downs and loss of gas monetization through loss of accuracy.

The result is Sierra’s QuadraTherm Series of mass flow meters, perfect for successful biogas measurement in any environment. Tell us in the comments below. And be sure to read our free white paper download on Precise Biogas Measurement.

How have you solved the problem of precise biogas measurement with changing gas composition?

Field-Adjust For Gas Composition Changes, Retain Accuracy, Save Time and Money

Oil & Gas Thermal Mass Flow MeterWhen gas composition changes, typical thermal meters must be sent back to the factory to be re-calibrated in order to maintain required accuracy levels.  All of this is a costly, time-consuming endeavor.

Imagine the time and money you can save by not having to send your meter back to the factory for calibration every time your gas composition changes?

Fortunately, oil/gas engineers can field-adjust gas composition on thermal mass flow meters for flare, Vapor Recovery Units (VRU), and storage vessels with Sierra’s QuadraTherm with qMix gas mixing software. The  QuadraTherm with qMix allows end users to manage gas composition changes in the field right from the Smart Interface Program (SIP) without ever sending the flow meter back to the factory to recalibrate the meter for the new gas composition. This makes meeting evolving government regulations and reporting easy for oil/gas engineers and operators.

Qmix is Powerful yet Simple

Sierra’s gas mixing software package included with every QuadraTherm thermal mass flow meter is a unique feature of the Smart Interface Program (SIP) unlike anything available on the market for industrial mass flow meters.

Watch qMix Video

Benefits of QuadraTherm with qMix

QuadraTherm with qMix Gas Mixing Software allows end users to:

  • Field adjust and maintain flow meter accuracy if gas composition changes
  • Avoid costly recalibration: No need to send unit back to the factory if gas composition changes
  • Quickly create and upload unlimited gas mixtures onto one meter-free of charge
  • Save custom gas mixtures onto your personal “My Gases Database” for later use
  • Benefit from Sierra’s proprietary, ever-improving “Sierra Gas Database” to download more accurate gases

Sierra’s QuadraTherm with qMix is the perfect solution for challenging upstream production applications.

Part 1: Emerging Trends of Thermal Flowmeters

In this guest post, I’ll be comparing the Coriolis and Thermal flowmeter markets, an interesting undertaking when you consider some of the facts. Both technologies were introduced about the same time, in the mid-1970s. But the worldwide Coriolis meter market has grown to exceed $1 billion, while the Thermal flowmeter market is valued at less than 15 percent of that. Why the difference?

Here are some important differences between Coriolis and Thermal flowmeters:

  • Coriolis flowmeters are widely used for liquids as well as gases, while Thermal flowmeters are used almost exclusively for gases.
  • Coriolis flowmeters are used for custody transfer applications, while Thermal flowmeters have yet to be approved for custody transfer.
  • Coriolis flowmeters are used to measure petroleum liquids, unlike Thermal meters. With oil prices at over $100 per barrel, this is a high-value measurement that requires high accuracy.
  • Coriolis flowmeters are more accurate on the whole than Thermal meters. Accuracy is especially important for custody transfer applications.
  • Coriolis flowmeters cost more than Thermal flowmeters, driving up the total revenues for this technology. Some of the new 14-inch Coriolis meters cost in the range of $75,000.

What can a thermal flowmeter supplier do to increase their visibility and performance when compared to Coriolis meters?

  • Develop more accurate meters. While some Thermal flowmeters have achieved accuracies in the range of one percent, this is not sufficient for many process applications.
  • Find a way to more effectively handle liquid flow measurement. This may be prevented by the technology, but it is worth looking at.
  • Try to find a way to accurately measure crude oil and petroleum liquids. Again, this may be prevented by the technology, but it would help Thermal flowmeters take advantage of the fast-growing energy markets.
  • Work to obtain custody transfer approvals, especially for custody transfer of natural gas. This would mean having the suppliers work together with end-users to draft a standard. Of course, in order to do this, Thermal flowmeters would have to be developed to meet current custody transfer standards.

As you can see, developing Thermal flowmeters that can handle all of these requirements is no easy task. But as I’ll share in my next post, Sierra Instruments has been up to the challenge, having become a leader in accurate Thermal flowmeter technology. Read More…

Jesse Yoder, Ph.D., is president of Flow Research Inc. in Wakefield, Mass., a company he founded in 1998. He has 25 years of experience as an analyst and writer in process control. He specializes in flowmeters and other field devices, including pressure and temperature products.



Everything You Need to Know About Sub-Metering Natural Gas

Slash Your Facility's Natural Gas BillWe’ve written quite a bit about the benefits of using thermal flow meters to sub-meter natural gas in large facilities. So much so, that we’ve decided to create one post that can be your go-to resource for finding information on the topic. Here you’ll find links to easily digestible content like infographics and SlideShare presentations, as well as technical articles and a white paper.

The Secret to Slashing Your Facility’s Natural Gas Bills [Infographic]
This infographic will provide you with the nuts and bolts, the main benefits and advantages of using thermal flow meters for natural gas sub-metering. Did we mention it can save you up to $25,000 annually on your natural gas bill?

Conserve Energy & Save On Your Natural Gas Bill with Sub-Metering [SlideShare Presentation]
Similar to the infographic, this SlideShare Presentation presents information on confirming the accuracy of natural gas bills using precision thermal flow meters to sub-meter natural gas in an easily digestible manner.

Challenges with Sub-Metering Natural Gas Part 1 and Part 2 [Blog Posts]
There are many challenges facilities face when sub-metering natural gas, such as changing composition and deliver pressure. Sierra’s Scott Rouse, our resident sub-metering expert, explores these challenges and how you can overcome them in this two-part blog series.

Advantages of Flexible Flow Measurement in Sub-Metering of Natural Gas [Article]
Originally published in Gases & Instrumentation Magazine, Scott Rouse takes an in-depth look at the technology and science behind how thermal flow meters can more accurately sub-meter natural gas.

Sub-Metering of Natural Gas [Free White Paper]
Delve into the technical details of how thermal flow measurement delivers highly accurate sub-metering. Learn the background on natural gas distribution and allocation, the challenges of changing gas compositions and delivery pressure, pros and cons of current meter choices, and innovative and economical new solutions.

Do you have questions about natural gas sub-metering or natural gas submeters? Ask us in the comments below!

Totalize Multiple Gases Independently: Watch Video!

The need to measure, totalize, and monetize gas flow is not going away. In fact, the requirement to accurately totalize and monetize gas is becoming even more critical with our boom in natural gas and other industrial processes. Almost all mass flow meter companies have the ability to totalize one gas being measured. This is pretty standard practice.

What happens when the customer needs to switch mixtures during a process and totalize multiple gases? They may either invalidate their running total or manually record the total and reenter the values later. Neither option is optimal.


More and more often, industrial applications require totalization of multiple gases. Recently, a customer had an application where one mixture was flowing for most of the process, but at certain times a blowout phase was initiated which drastically altered flow rate and composition. The customer needed the ability to totalize these two phases separately. The new Flow Totalizer for the QuadraTherm 640i/780i mass flow meter meets this need.

In flare gas measurement, for example, as gas compositions change, meters are required to totalize the flow of multiple gas compositions. These applications present a problem when you attempt to totalize their flow. When compositions shift without any adjustments being made to the meter, the totalization will be directly affected resulting in invalid results.

Sierra has solved these problems with our new Flow Totalizer feature and its ability to independently totalizing each gas mixture. With Sierra’s QuadraTherm mass flow meter, mixture profiles can be generated for known compositions and loaded into the meter’s gas slots. Then, as composition changes, these profiles can be applied and totalized independently, allowing the end-user to achieve a much more accurate mass flow total which isn’t spoiled by fluctuating compositions.

Features of Multi-Gas Flow Totalizer for Mass Flow Meters

  • Allows an end-user to totalize the measured flow for each of these gas ‘slots’ independently.
  • Allows for a smooth transition between gas mixes, while ensuring accumulated flow totals remain continuous and accurate.
  • Adjust Units per pulse and pulse width for each gas slot independently.
  • End-users have the ability to create unique flow totalizer profiles for each of their gas mixtures.
  • View the totalized value of multiple gases.
  • Reset totalizer.

Learn more about the new Flow Totalizer and its applications.

Thermal Mass Flow Meters Offer Oil & Gas Companies Lowest Cost of Ownership

Flare Gas Article in Hydrocarbon EngineeringThe Wall Street Journal recently reported that oil prices have hit a rock bottom $40 a barrel, the lowest since 2009. How does this affect the oil companies? Well, the consumer gets the benefit of the low pump price which does loosen discretionary spending, but the oil & gas companies are hurting-spending less money on capital investment due to tightened budgets. Flow meter manufacturers are feeling this pinch because oil & gas companies are just not driven to spend money on upstream oil & gas flow meter applications.

Luckily, recent Sierra thermal mass flow innovation with the QuadraTherm 640i/780i with qMix gas mixing softward offers oil and gas companies a cost-effective solution for upstream oil and gas applications like flare gas measurement, vapor recovery units, and storage vessels.

CEO of Sierra, Mattnew Olin,  explores in the July 2015 issue of Hydrocarbon Engineering magazine how QuadraTherm thermal mass flow meters with qMix gas composition adjustment are now a real alternative to ultrasonic flow meters and offer oil & gas companies the lowest cost of ownership to measure flare gas in upstream oil applications.

The article summarizes:

1. How gas composition changes in the flare making it very difficult for some flow meter technologies to remain accurate without factory recalibration

2. The total cost of ownership between competing technologies

3. How qMix gas mixing software allows users to create and upload a new gas composition in the field-without factory recalibration. Learn More.

In this tough market, oil & gas companies appreciate the flow instrument with the lowest cost of ownership to get the desired results. This is why Sierra’s innovations with the QuadraTherm 640i/780i with qMix couldn’t come at a better time.

To find out more about QuadraTherm and precision flare gas measurement, read the full article today .

Break from the Shackles-Mid-to-Large Size Facilities Verify Utility Company Billing

As we have all been hearing in the news, natural gas is becoming a very valuable and abundant natural resource. Almost all of this increase is due to the projected growth in shale gas production which will grow to 16.7 trillion cubic feet in 2040. Now comes the big question: how are utility companies going to capitalize on this natural gas boom and how will consumers fare? This is where accurate natural gas measurement becomes critical both for utility companies and consumers, particularly in larger gas consuming mid-to-large size facilities.

Without natural gas billing verification, mid-to-large size facilities are at the mercy of utility company billing.  To break the shackles of utility companies, mid-to-large size facilities use mass flow meters to sub-meter the natural gas entering their facility. This verifies their utility bill and shows billing discrepancies. This obviously sounds like a good idea. But not many mass flow meters can accurately measure natural gas with its changing compositions and delivery pressure.  The answer to this challenging application is to use a flow meter that can deal with the changing gas compositions and density changes caused by pressure variations.

In the September/October 2013 issue of Gases & Instrumentation magazine, Sierra’s VP of Product Design, Scott Rouse, takes an in-depth look at sub-metering natural gas, including challenges associated with the varying composition of natural gas and the flow meter measurement solutions Sierra is committed to providing.

We hope you find this article insightful and encourage you to visit our Library for other in-depth articles on flow meter measurement.

The New Vortex iSeries has Arrived!

InnovaMass. Reinvented. I am proud to announce on behalf of our entire development team, our completely re-designed, next generation InnovaMass 240i and 241i vortex volumetric flow and multivariable mass flow meter product line. Learn more…

The all new iSeries InnovaMass 240i inline and 241i insertion vortex flow meters are manufactured at our brand new assembly and calibration facility in Monterey, California. I think you will find this new product exemplifies on our tradition of innovation with improvements and features like:

  • New Raptor II OS operating system “Flow Engine”
  • 10x faster processing speed
  • It has Apps like: FloPro, qMix, Dial-A-Pipe, Dial-A-Fluid
  • Easy field setup, meter tuning and instrument validation
  • Field firmware upgrades
  • And much more

Learn more… Reduced Cost of Ownership: With five high accuracy measurements available from InnovaMass, total cost-of-ownership plummets. Lower initial cost, less complex installation, and reduced maintenance costs contributed to significant overall savings. Did You Know?  In 1997, Sierra was the first to design and introduce a multivariable mass vortex flow meter to the world with InnovaMass. Today, multivariable mass vortex units are an industry standard. InnovaMass is a Registered Trademark of Sierra Instruments, Inc., Monterey, California