Tick-tock feedstock - time to drive profitability

Paul Boughton

Ron Beck, Caleigh Holden and Vince Ye look at how to characterise and analyse crude assay data with breakthrough technology.

The global refining and petrochemical industry has become more complex. With increasingly diverse crude sources, being able to easily evaluate and model the effects of crude feedstock selections is essential to achieving a competitive advantage.

The world's crude sources and refining capacity continue to expand and shift geographically, which increase the crude purchase and petroleum products purchase decisions.

Refinery closures and divestitures in some areas, such as the USA, Europe, Japan and Australia, create opportunities for the nimble organisations. Getting the right crude oil to the right refinery is vital to turning those opportunities into profits. Analytics based on software models correctly calibrated for accuracy can provide real-time decision tools for the trader, engineer and refiner planner confirming the end product can be delivered on time, at the quality expected and at maximum possible profit on a real-time basis to support business decisions. With competition increasing year on year, time is ticking for many refineries to protect margins and examine their processes, including feedstock selection, to extract every bit of profit possible from their operations.

Refining simulation

The implementation of advanced software makes accurate and rigorous petroleum refining simulation widely accessible to more refining organisations with clear and simpler visualisation tools to understand model results. This helps industry leaders to make complex business decisions for the best possible use of their production operations and to more accurately forecast and understand the results. Isolated worlds of the refinery engineers, the planners, the scheduler and the traders, can now be closely tied together to achieve a level of collaboration with improved ability to optimise the entire refinery operation.

Planning and scheduling models can be kept up-to-date through simple and immediate access to results of engineering models tuned with current operating results, increasing confidence that the plan will more closely mirror the actual production performance.

Also, the ability to perform multi-unit engineering studies supports use and configuration of existing refining units for difficult and complex crudes, such as heavy and dirty oils. Overall, integrated process engineering software provides faster, more accurate and frequent analysis to achieve refinery profitability.

Analysis and accuracy

A crude oil assay, the laboratory profile of candidate crude properties, is the unique fingerprint and basis for understanding how a crude feedstock will perform in a refinery configuration. Assay data helps engineers and planners determine for particular crudes (or more typical mix of crudes), whether that oil feedstock is compatible with a particular petroleum refinery train or whether the new candidate crude itself might trigger issues reducing yield and quality or restricting product mix flexibility in that facility.

Refiners continually seek to speed up and improve feedstock purchase decision-making ability through new techniques and technology to analyse their options rapidly when giving instructions to traders. While finished product demand is weak in some regions, crude costs remain high, putting downward pressure on margins and if the crudes available for purchase are heavier, it presents processing and environmental challenges. As crude production declines in established producing areas such as the North Sea, refiners are now forced to consider new sources discovered in the last few years to replace existing declining sources.

Today, the market is experiencing shifts in the composition of incoming crude, which creates challenges and opportunities. For Middle East petrochemical producers, strategic priorities are changing as regional feedstocks are increasingly consumed domestically, so creating added value products is now a clear business strategy.

As these organisations integrate their operations to move downstream in the value chain, operational decisions become more complex against a backdrop of market uncertainty and shifting sources. Also, with the increased supply of shale gas and corresponding lower gas prices in North America, the USA's petrochemical producers are gaining a competitive advantage in the global market, shifting purchase and sale strategies. Companies across the globe are experiencing a new era of expanded feedstocks and commercialisation.

There are several key trends in application and use of software modelling tools in this new environment. First, rigorous engineering simulation models have become extremely important in understanding how to best operate a facility across the dimensions of flexibility, yield, quality and energy. Companies are increasingly employing engineering models, calibrated against current plant conditions, for tuning, decision-making, evaluating feedstock and product options.

At the same time, planning software is being increasingly used to evaluate both crudes and petrochemical feedstocks faster. Producers have started to take advantage of the engineering models to more accurately and frequently update the planning models, increasing planning validity and accuracy. Models are dependent on the accuracy of the hydrocarbon characterisations, so companies need powerful process engineering tools that can characterise crudes, analyse multiple feedstocks, track petroleum properties and carbon emissions and leverage activated energy and economics for optimal operations. Advances in the ability to accurately characterise crudes from limited assay data is one of the most important areas of software innovation.

With today's sophisticated software, it is easy to update refinery planning and scheduling. Aspen HYSYS Petroleum Refining (an engineering simulation system) includes tools to easily import and export petroleum assays to and from Aspen PIMS (a refinery planning system) with the new Aspen Assay Management. Companies can also automate the export of rigorous reactor models to Aspen PIMS. This improves planning software accuracy, leading to better and more profitable refinery feedstock selection.

Many companies see significant benefits with the adoption of process modelling software. For example, Saudi Aramco E&P increased throughput by 3-8%, reduced planning time by 50-70%, reduced inventory by 15-35% and made 3-5% energy savings by integrating Aspen HYSYS and Aspen PIMS across all major surface facilities. S-Oil has seen its energy loads reduce by over 100MW per year, saving over US$39 million.

Ron Beck is director for Engineering and Caleigh Holden and Vince Ye are product managers, Refining at AspenTech. The company is based in Reading, Berkshire, UK.

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