Identify, Quantify and Rectify Vent Gas to Stay in Compliance
June 8, 2015

IQR - Identify, Quantify, Rectify

HY-BON uses its IQR Survey as the method to Identify, Quantify and Rectify leaks from venting, flaring and fugitive leaks of natural gas at oil and gas production facilities. The venting sources include storage tanks, glycol dehydrators and facility blowdown vents.  Fugitive leaks include leaks from valves, flanges, connections, seals and pressure relief devices – with the focus being on tank hatches and tank relieve valves. IQR surveys can be used for volatile organic compounds (VOC), greenhouse gas (GHG) and hazardous air pollutant (HAP) reporting and emission control compliance. 

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Identify

Identify all sources of venting of natural gas at the location – fugitive and venting sources.

Using the latest gas detection technology, HY-BON’s IQR team provides visual documentation of the venting fugitive emission sources. The FLIR GasFind Infrared Camera is used for gas leak detection and site surveys. This can be a part of a company’s leak detection and repair (LDAR) program.

The FLIR camera makes visible many chemical compounds and gases that are invisible to the naked eye. HY-BON’s surveys produce a video of the scanned area with the fugitive gas appearing as smoke in the video. The image is viewed in real time and can be recorded and stored, helping with regulatory compliance. These videos can be used to target repairs for leaks – especially those associated with storage tank thief hatches and pressure relief devices. Something needed prior to measuring the flowrate of vent gas from storage tanks.

Federal (EPA) and state agencies and nongovernmental agencies (NGOs) and citizens are actively using IR cameras to remotely find leaks and fine oil and gas operators.

 HY-BON also can use a Remote Methane Leak Detector (RMLD) for leak detection. The RMLD uses a laser based natural gas sensor. When the laser passes through a gas plume, the methane absorbs a portion of the light, which the RMLD then detects. The signal is processed so that methane concentrations can be reported in parts per million meter or PPM-M. The RMLD is capable of measuring down to 1 PPM-M. The RMLD has ultrafast response for methane leaks, locates methane up to 30 meters away and is methane specific – so no false positives.

Quantify

Quantify the amount of venting of natural gas so you know the regulatory requirements. 

HY-BON’s IQR team has the largest selection of measurement tools available in the industry. Component leaks from every part of the oil and gas industry have been measured and documented.

Quantification of fugitive leaks and vent gas can use the following methods:

  • Turbine meters for measuring vents and flare lines
  • Thermal mass flow meters for measuring vents and flare lines
  • Hi Flow Samplers for measuring leaks of gas from fugitive sources such as valve, flanges, seal or where the gas has been diluted with air

Why use direct measurement to quantify venting emissions?

  1. The data can be used to determine if emission controls are required based on measured amount. Direct measurement may indicate that flow rates are low enough to eliminate or decrease the amount of reduction required.
  2. The IQR survey determines natural gas flowrates and chemically analyzes a sample of the gas. This data can be used to design the correct Vapor Recovery Unit (VRU) or vapor combustion device (VCU) for the application based on the gas recovered and the cyclical flowrate of gas.
  3. The survey data can be used so you know the volume and mass (tons) of emissions (VOC, GHG, HAP) that are vented or flared. This can help with air permitting and compliance verification. It can also help in determining the amount of GHGs required to be reported under 40 CFR 98 Subpart W.
  4. It can be used to design and engineer the proper emission controls based on facility operating parameters.
  5. Direct measurement often provides a higher degree of accuracy as compared to simulation tools and calculations.

Storage Tank Measurement

Once all storage tanks are sealed (no leaks) and all gases can be directed to vent only through a common vent and/or through the thief hatch, vent gas flowrate can be measured by a turbine or thermal mass flow meter.  Measurement is normally for a duration of 6 to 24 continuous hours so that you identify the full range of cyclical flowrate (min/max) of vent gas, as well as an average daily flow.

During the measurement, we collect a sample of the gas vented from the tank (i.e., take a sample from inside the storage tank) and have the gas sample chemically analyzed to obtain gas BTU value, VOC content and methane content.

During the IQR survey we can determine facility operating conditions (e.g., pressures and temperatures of separators, compressors and pipelines) needed to engineer the appropriate emission control options.

One control option is to collect the gas with a vapor recovery unit (VRU) for compression and then injection of the gas into system (compressor suction, low pressure system). Also the vent gas may be routed to a flare or vapor combustion unit (VCU). Some companies elect to use vapor recovery towers (VRT) for collection of most of the flash gas and then route tank vapors to a VCU. Low VOC volumes from storage tanks (<5,000 scf/day) may be controlled using the Convervation Filter (CV). 

Fugitive Leak Measurement

HY-BON can measure leaks from fugitive emission sources. We can use the Hi-Flow Sampler which is a leak measurement tool that is portable, intrinsically safe and battery powered. It can determine the rate of gas leakage around various pipe fittings, valve packings, and compressor seals found in natural gas transmission, storage, processing, gas gathering, production, offshore, and distribution facilities.

A component’s leak rate is measured by sampling at a high flow rate that captures all the natural gas leaking from the component along with a certain amount of surrounding air. By accurately measuring the flow rate of the sampling stream and the natural gas concentration within the stream collected, the gas leak rate can be calculated.

Use of the Hi Flow can be used to develop emission factors for leaks from fugitive emission sources. The leak rate will be in terms of volume of gas in scf per unit time for the component. This may be required or desired for a facilities greenhouse gas (GHG) reporting requirements under 40 CFR 98 Subpart W.

Rectify

Rectify emissions by using a Vent Gas Management (VGM) system to minimize air pollution. 

Correct the venting of natural gas by recovering the gas using vapor recovery or a flare or enclosed vapor combustion device to burn the gas. NSPS OOOO and state air permitting rules will need to be considered when choosing the right emission control source. With all of the bad press that the O&G industry is getting regarding flaring of natural gas, many companies are choosing vapor recovery as the first option for controlling venting of natural gas. Natural gas recovered and sent to sales increases company profits and puts out a flare that will only get more attention from regulators.  

 

 

HY-BON IQR Services

Let HY-BON help your company Identify, Quantify and Rectify (IQR) your facility emissions.  Using our IQR services and our ongoing Vent Gas Management (VGM) system we can help you stay in compliance with NSPS OOOO and state air permits and make your company money. HY-BON’s vent gas management (VGM) system is a cost effective way to take this issue off of your plate. We use “best in class” vapor recovery units (VRU), Vapor Recovery Towers (VRT) and enclosed combustors (ECU) to comply with storage tank emission control requirements.