Decarbonisation via Automation

Online Editor

Veronica Constantin explains why automation technologies are essential in developing oil and gas sustainability

Environmental sustainability is one of the biggest challenges facing our world today. The oil and gas industry has a big part to play in helping to ensure that future generations will inherit a healthy planet, by incorporating environmental sustainability strategies into its business models. According to the IEA (International Energy Agency), indirect greenhouse gas (GHG) emissions specifically from oil and gas operations are approximately 5,200 million tonnes of carbon-dioxide equivalent, which amounts to around 15% of the energy sector’s total GHG emissions.

Oil and gas industry executives are under increasing pressure to make a strategic shift in their environmental sustainability. That pressure is primarily coming from activist investors, increasingly conscious of environmental issues, who are challenging major companies on their climate policies and decarbonisation targets. As a result, many majors have already announced their own plans to achieve net-zero emissions by 2050, relating specifically to emissions from producing, refining and processing oil and gas. To achieve those targets, the industry must consider a range of options, but changes to processes and minor adjustments that help companies reduce their energy consumption and emissions offer the lowest cost and maximum benefit. Equipment performance and reliability are two key areas that can be addressed.

Gas Flaring

Gas flaring to relieve pressure during normal operations is a significant source of GHG, and this can be exacerbated by non-routine flaring caused by the poor reliability of devices such as control valves or compressors. To prevent this, organisations can implement predictive maintenance strategies and condition monitoring solutions that prevent unexpected failures.

Increasing vibration indicates problems, such as blade, bearing, shaft or coupling issues that can lead to compressor failure and a potential unit shutdown. Online compressor health monitoring solutions provide early warning alerts of excessive vibration and bearing wear, allowing technicians to perform scheduled repairs or adjustments that can prevent unexpected downtime that leads to excessive flaring.

These solutions are enabled by wireless sensors and networks that instantly interpret key asset health data, with pre-built analytics giving operators the information they need to make faster and more informed decisions. Similarly, tools such as Emerson’s Plantweb Insight software applications help to eliminate the guesswork for pressure relief valve monitoring. This application provides indication of pressure relief valve releases, including start and end time and production and emissions loss. This continuous monitoring can reduce unplanned shutdowns that impact production, minimise emergency flaring and reduce emissions.

Plantweb Insight applications can instantly interpret key asset health data with pre-built analytics that give operators the data they need to make decisions that impact energy efficiency. The Plantweb Insight Steam Trap application determines the online health status of steam traps, helping to reduce loss steam and energy waste, whilst the heat exchanger application provides in-depth monitoring of shell and tube heat exchangers by analysing plant sensor data and delivering predictive diagnostics that help operators maintain optimum performance and energy efficiency.

These analytics tools extend to pipework corrosion and erosion monitoring, with non-intrusive online applications monitoring the metal thickness, which is a major factor in determining the heath of piping. Changes can be detected in minutes, enabling corrective actions to be performed before damage occurs that otherwise would impact the health of the asset and create the possibility of emissions due to leaks.

Leak Detection

Earlier detection of leaks is another area where significant improvements can be made. Ultrasonic gas leak detection devices enable the rapid detection of gas leaks in high pressure processes, such as pipeline monitoring or gas compressor stations. These innovative solutions use acoustic sensors to identify fluctuations in noise that are imperceptible to human hearing within a process environment. Unlike traditional gas detectors that measure accumulated gas, ultrasonic gas detectors “hear” the leak, triggering an early warning system. These solutions provide rapid detection response times and can be applied to air cooled heat exchangers, compressor stations, generators, gas metering skids, well bay areas and separators.

Energy Monitoring

The deployment of advanced measurement technology and monitoring systems helps manufacturers to not only understand equipment health and performance, but also its environmental impact. Using wired and wireless plantwide digital networks to collect data, real-time energy management information systems can then automate the process of mapping and managing energy consumption across a site, as it is being consumed. With energy usage measured, operators can receive real-time alerts via user dashboards or emails notifying when energy consumption is above what is expected, actions may be taken to reduce energy costs. Operators know which pieces of equipment are the major consumers of energy in their plant but using analytics and trending tools to identify reduction in efficiency and increases in consumption over time ensures that the necessary maintenance and improvement programmes are put in place.

Energy Efficiency

Efficiency is a factor in every part of the industry, of course, but new downstream-specific technologies can make a big difference. Medium-temperature heat pumps in refineries, for example, reduce the amount of primary energy used in distillation. Another area in which major energy efficiency improvements can be achieved for a low initial cost is optimising the performance of process control loops. Control schemes are generally designed to keep the process stable and minimise variability, but in many cases this does not happen. In a typical plant, almost two-thirds of control loops are underperforming, which can be due to many reasons, including poor valve performance, incorrect loop tuning and inappropriate control strategy. As a result, huge amounts of energy are wasted because of suboptimal control.

Poor tuning leads to greater process variability. In turn, this leads operators to run the plant away from the most efficient regions, which are typically close to operating constraints, such as quality limits, to allow for a greater margin of error. Despite this, many facilities do not have a formal, consistent approach to troubleshooting, and the root causes of issues can therefore go undetected for weeks, months or even years.

Emerson is addressing this issue by providing a range of tools and services that can help achieve significantly better control performance. Among these is the DeltaV Loop Service, which is designed to optimise system reliability and performance. The performance of every control loop is measured and a control performance score indicates how many control loops have limited control, high variability, uncertain inputs, or are not in the normal operating mode. Control performance experts, working remotely, provide monthly reviews of control performance, identify issues, make recommendations for corrective actions and establish a control performance roadmap with prioritisation as to the control loops that have the greatest impact on the bottom line. This aims to maximise the number of automatic and well-performing control loops, leading to greater product quality and throughput, fewer operator interventions on-site, and increased energy efficiency.

Where there are issues that require more than proportional integral derivative (PID) control, Emerson provides advanced control technologies that automatically account for process interactions and difficult process dynamics, and easily handle issues such as excessive deadtime and loop interactions. Employing these advanced control techniques improves product quality by dramatically reducing key process variabilities, increases profitability by operating closer to process constraints and limits, and further increases energy efficiency.

Reducing energy consumption and emissions can be challenging, but the digital transformation of operations can deliver step change improvements. Knowing how to begin this transformation is key, and an approach that begins with a digital maturity model roadmap can help companies get started. This type of assessment enables companies to evaluate their operations against others in their industry as well as determine what operational areas are likely to yield the greatest return on investment.

Veronica Constantin is with Emerson

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