How does flow control offer solutions to damaging emissions?

Valve World Americas, August 2022

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How does flow control offer solutions to damaging emissions?

There is no denying that the climate crisis is a critical area of concern for governments, businesses, and individuals worldwide. The urgent need for action is made clear when considering rising temperatures, extreme weather events, and food and water insecurity. The Paris Agreement of 2015 set warming limits to below 2°C, and ideally 1.5°C, to avoid catastrophic impacts of climate change. Since that agreement, governments have reconfirmed importance of this, such as at COP26 summit in Glasgow in November 2021. Here, world leaders committed to: i) ambitious emissions reductions by 2030; ii) phasing out unabated use of coal; iii) encouraging investment in renewables and iv) significantly reducing methane emissions. The oil & gas industries have an essential role to play.

Reducing unnecessary gas emissions, and focusing on using electric actuators within oil & gas operations, is an important step in the Paris Agreement and COP26 targets, and the race to Net Zero by 2050.¹ Traditionally, spring-return and diaphragm actuators powered by the produced gas have been a favored form of control in oil & gas applications (especially in isolated locations and inaccessible environments, such as remote wellheads). Flow control that is instead electrically powered will reduce or negate associated emissions. In doing so, it promises more environmentally friendly operations and compliance with increasing global emission control mandates.

Methane Emissions in Oil & Gas

Before exploring how efficient flow control can negate or reduce gas emissions within energy production, it is important to understand how they occur and their destructive potential. The gas that has received the most attention in recent years is methane. By volume, methane sits behind carbon dioxide; but it has a disproportionate impact on the environment due to its high global warming potential (it is 28 times more potent than carbon dioxide). The abatement of current methane levels is critical in achieving essential emission reduction and climate crisis targets. Approximately 20 to 25% of human-derived methane emissions are from the oil & gas industry. The majority of those are from upstream operations. Leaks and emissions come from production sites and transmission and distribution systems. Methane is also commonly vented and flared. Pneumatic flow control is, therefore, an obvious choice when deciding what equipment to upgrade. In all cases, electric alternatives will reduce or negate gas emissions.

Electrification

Electrification is a cornerstone of attempts to clamp down on emissions within oil & gas operations; it has a significant role in essential decarbonisation efforts. Even with an increased focus on renewable forms of energy, it is likely that individuals will rely on oil & gas for some years to come. It is therefore essential that oil & gas is produced as efficiently as possible, with a reduction in emissions created and a reduced impact on the environment. As set out by the International Energy Agency: “Producers that can demonstrate strong and effective action to reduce emissions can credibly argue that their oil & gas resources should be preferred over higher emission options.” The same logic applies to flow control operators; actuators in oil & gas applications that can provide flow control with reduced/no emissions are ideally placed to play a leading role in energy provision both now and in the future.

The oil & gas industry is a valve-intensive area, with associated actuators found on all sites managing the flow of crude oil, gas, condensate, and water. Traditionally in upstream applications, actuators are powered by the motive gas. The use of pneumatic flow control runs the risk (or, in some cases, certainty) of gas emissions that are harmful to the environment. Using electric flow control products in their place means more efficient operation, reduced emissions, and improved environmental and safety performance. Electric actuators require only an electric power supply, with no venting or leaking of gas. Therefore, electrification is an important tool in reducing emissions in such a valve-intensive industry.

Mitigating Upstream Leaks

Upstream applications are an area of particular focus for electrification, as they provide the most significant number of opportunities to upgrade from existing high-bleed pneumatic devices that cause emissions.

A recent example of flow control electrification is the installation of intelligent electric actuators at an oil field in the North Sea, aiding in creating an allelectric platform. The Johan Sverdrup oil field is one of the largest offshore development projects on the Norwegian continental shelf; the use of electric actuators is part of an electrification programme to produce oil in a way that creates reduced or negated levels of emissions. The actuators were installed to provide flow control services across the site’s drilling, riser, process, and living quarters.

Upgrading existing pneumatic actuators to new electric ones is an increasingly common practice. Another example of the installation of electric actuators was seen at several natural gas pressurereducing stations in Belgium. Electric actuators replaced existing pneumatic actuators at sites operated by energy infrastructure group Fluxys. The previous actuators used gas as the control medium, causing venting into the atmosphere. Upgrading or retrofitting from pneumatic to electric flow control solutions is a core tenet of the electrification practices within oil & gas operations that cracks down on damaging leaks and fugitive emissions.

Midstream Leak Detection

Regarding midstream activities, fugitive emissions are less likely to occur. But any leaks must be quickly detected and dealt with when pipelines travel across hundreds and thousands of miles. Reliable technology that quickly isolates a break in remote pipelines is essential in maintaining the efficiency and safety of such a midstream application. Combined with a fluid power actuator, an Electronic Line Break (ELB) device can meet this challenge. The ELB will swiftly identify and facilitate the isolation of a ruptured or broken section of the pipeline by monitoring pipeline pressure. By comparing rate of pressure drop (RoD) or rate of pressure rise (RoR) readings against pre-determined limits set by the operator, a microcontroller can energise a solenoid valve which allows pipeline gas in the actuator’s circuit manifold to move the valve to the closed position and cut off the affected part of the pipeline. This kind of technology can act quickly in the event of a pipeline break to isolate the appropriate pipeline section and reduce potentially damaging safety, financial, and environmental impacts.

Downstream Leak Reduction

Within downstream applications, there are multiple opportunities for fugitive emissions to escape. Efforts to combat this sort of leakage can cumulatively add-up to having a significant positive effect in reducing these emissions. For example, gas distribution channels often see methane emissions. Natural gas pressure reducing stations are a common sight across the USA. They regulate downstream gas pressure for delivery to domestic customers. When adjustments are made, the methane used as the motive power is vented into the atmosphere. Pneumatic controllers with high-bleed I/P positioners are usually used to facilitate this. An alternative is an electric actuator; they can be fitted directly on the regulator to adjust the pressure set point automatically. They can be operated remotely and do not produce emissions or waste gas during operation; there is no constant bleed. This solution also does not require a continuous supply of power.

Conclusion

The drive to reduce emissions within oil & gas operations is part of a broader global campaign to tackle the climate crisis. Oil & gas operations, especially upstream, are widely acknowledged as important ones to target as part of a decarbonising energy sector transformation. Electrification of flow control systems by replacing existing pneumatic actuators with electric ones is vital in reducing damaging emissions such as methane and carbon dioxide.

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