As the drive towards energy independence in the United States continues at full speed, oil and gas companies are turning to hydraulic fracturing to increase production. Increasingly stringent state and national regulations for flare gas in particular now require the installation of mass flow measurement instruments to measure waste and excess gases burned off as a result of the hydraulic fracturing process. For gas wells alone, the EPA estimates that the cost of compliance will rise to $754 million per year by 2015.1
Given the immense number of flares that are to be regulated, there is a need for more cost-effective mass flow measurement technologies. Multi-path ultrasonic flow meters have been widely used for flare gas measurement, but they are extremely expensive and have marked limitations. To comply with regulations, oil and gas companies need new flow meter alternatives that are accurate, durable, reliable and economical.
This paper reviews flare gas flow measurement challenges and describes how several recent innovations in thermal mass flow sensor technology gives end-users an alternative metering choice to consider. Of particular interest is four-sensor thermal technology coupled with an advanced math model algorithm that works in tandem with the American Gas Association’s (AGA) compliant gas property database. In combination, these technologies allow the user to adjust the instrument and retain accuracy as flare gas compositions change in the field over time. The ability of this new breed of four-sensor thermal meter to adjust for changing gas compositions gives end-users a significantly lower cost alternative to four-path ultrasonic meters.
Flare gas mass flow metering innovations promise more economical choices