The question of pollution

Gas flaring and the depletion of the Ozone layer. By Alex Keys

The planet has seen rapid warming in the past few decades. The consequences of global warming are largely due to increased greenhouse gas emissions – with CO2 proving to be significantly damaging to the atmosphere. Gas flaring – the process of burning off excess natural gas – releases CO2 into the atmosphere. If oil and gas companies are routinely flaring gas, how can they proactively reduce the effect on the Ozone layer? Are there techniques available to curb the impact of gas flaring?

The flaring climate
The flame at the top of an oil rig is an iconic image for the oil and gas industry. Flare stacks are used to burn off flammable gas released by pressure valves during unplanned over-pressuring of plant equipment, often taking place during start-ups and shutdowns in production when the volume of gas being extracted can be extremely uncertain. Flare stacks provide critical to on-site safety – the alternative to allowing the gas to escape would be a significant build-up of pressure and the risk of explosion.

However, gas is not always flared for safety reasons. When crude oil is extracted and produced from onshore or offshore oil wells, raw natural gas also comes to the surface. In areas of the world lacking pipelines and other gas transportation infrastructure, this gas is commonly, or routinely, flared.

Gas flaring may help to ensure on-site safety, but it is also responsible for the release of substances into the atmosphere that deplete the ozone layer and contribute to global warming. Based on satellite data it is estimated more than 150 billion cubic metres (or 5.3 trillion cubic feet) of natural gas is released into the atmosphere each year through natural gas flaring and venting (otherwise known as cold flaring).

Venting refers to the controlled release of gases into the atmosphere over the course of oil and gas production operations. These gases might be natural gas or other hydrocarbon vapours, water vapour, and other gases such as carbon dioxide, separated in the processing of oil or natural gas. Venting is an alternative to flaring if gases are not damaging to the environment.

Gas flaring has long been considered the lesser of two evils compared to venting. While burning gas leads to the release of CO2 into the atmosphere, it is significantly less harmful to the ozone layer than methane.

The pledge for a greener industry It is in the interest of the entire industry not to routinely flare gas. If the industry could capture the substance at its source, it would significantly reduce the amount of environmental damage caused by flaring. Many countries have instigated taxation regimes against gas flaring and companies are now closely regulated.

The Zero Routine Flaring by 2030 Initiative was launched by the World Bank in 2015. It brought together governments, oil companies and development institutions that recognised flaring on the current scale was unsustainable and agreed to eliminate routine flaring no later than 2030.

The initiative has been endorsed by 57 organisations, including most of the major oil companies (BP, Eni, Repsol, Shell, Statoil, Total, as well as several national oil companies) and large oil-producing countries, including Angola, Canada, Mexico, Nigeria, Norway, Oman, Russia and the US – under former President Obama.

Though the Zero Routine Flaring by 2030 Initiative is not a legally binding commitment, these governments and oil companies have agreed to report levels of flaring and progress towards the initiative’s goal to independent regulators.

Accuracy first
Accurate measurement of gas flaring is central to achieving the objectives of the Zero Routine Flaring initiative. Global regulations and targets mean that emissions need to be recorded and shared with regulators as well as health and safety authorities.

By far the most effective technology for gas measurement is ultrasonic. Ultrasonic meters use sound waves to determine the velocity of a fluid flowing in a pipe. This technology does not obstruct flow, is low maintenance and extremely accurate.

Countries have even introduced regulation that enforces accuracy requirements for emissions reporting. Canada’s Directive 017 requires facilities flaring more than 500 m3 per day to record gas flaring to an accuracy of five per cent on single point meters – a measure echoed by the regulatory bodies in the United States and Russia.

A vision for future measurement
Historically, data on the volume of gas flared locally would have been recorded and shared periodically. Connected measurement technology means that this information can now be monitored and measured in real time through secure hosting in the cloud. When real-time data is fed into software such as a continuous emission monitoring system (CEMS), organisations can collect, record and report data remotely.

Providing they are connected to the internet, businesses can access CEMS data and analyse it using any connected device. Using cloud technology to record gas flaring, allows companies to build a better picture of trends over time. This information can be used to generate valuable insight that informs business strategy and streamlines emissions-heavy processes.

Consider a rig where flaring only happens after certain maintenance procedures. Real-time data from this can provide insight to more effectively manage the flaring process – reducing both the amount of wasted gas and consequent taxation paid. Over an extended period of time organisations may begin to see patterns emerging that enable them to more effectively predict which rigs will flare more gas than others.

Safety is paramount in the oil and gas industry but losing such high volumes of a scarce and valuable natural resource is hugely incongruous. New regulations, initiatives, and technologies – such as the remote monitoring and measurement of gas flow – should reduce routine gas flaring and ensure it is a process only deployed in an emergency.

Alex Keys is Fluenta’s Marketing Director. Founded in 1985 Fluenta is the global leader in flow sensing, measurement and management using ultrasonic technology. The company serves the chemicals, petrochemicals and oil and gas markets, where it is the leader in European off shore flare gas monitoring. Fluenta originates from Norway and has offices around the world, including the UK, Poland, Norway and the USA.

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