How Cognite Data Fusion helped OMV New Zealand automate multiphase flow allocation

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• Cognite worked with OMV to improve the process for calculating condensate-gas ratios and water-gas ratios.
• The solution is estimated to generate USD 1,250,000 in value a year.

Challenge

Gas production in OMV New Zealand operated field is constrained by market demand. Gas condensate, however, can easily be stored so that it can be sold at a later date. Therefore, while producing enough gas to meet demand, OMV, an Austrian integrated oil and gas producer that operates several fields worldwide, also aims to maximize gas condensate production.

All well production streams are comingled into a common separator at the onshore processing plant with no individual well liquid metering. Only wellhead wet gas meters (differential pressure, V-cone) are available to measure the individual well gas rates and hence, there are no facilities installed (onshore or offshore) to enable well testing using dedicated equipment.

Historically, excess field gas deliverability enabled the use of Deliberately Disturbed Well Testing (DDWT) techniques to record the change in total field liquid rates by beaning up or down individual wells to test the wells by difference. Production engineers at field will once a month analyze well perturbation data and manually calculate new condensate-gas ratios (CGR) and water-gas ratios (WGR) in a spreadsheet. As the data is often noisy and hard to interpret, the allocations sometimes prove to be difficult to calculate. The field production is also declining (depletion) and no longer has surplus deliverability under normal offtake conditions, therefore well testing by the same techniques will cause additional production deferment.

More accurate CGR and WGR allocations would provide a more precise understanding of the composition of the fluids that each well produces at any given time, enabling the company to maximize condensate production by simply ranking high CGR wells during low gas demand and optimize its operations at the field.

Solution

OMV and Cognite worked together to ingest data from four different sources, including OSIsoft PI and Aspen HYSYS, into Cognite Data Fusion (CDF). Once all the relevant data about condensate-gas and water-gas ratio allocations was stored in one place, the development team was able to create a system that automatically analyzes well perturbations. The system consists of a mathematical model that continuously identifies time periods with well perturbations and back-allocates field CGRs and WGRs to wells. The model output is visualized in a dashboard that lets production engineers easily track and verify results and adjust other models and systems.

Impact

OMV estimates that automating the process for calculating CGR and WGR at the OMV field generate about USD 1,250,000 a year in value by increasing gas condensate production and eliminating the need to run manual calculations.