Sigmafine App for LNG, LPG and NGL

by Pimsoft Inc.

This Sigmafine App implements inventory and transfer compensation calculations for LNG, LPG and NGL in the OSIsoft PI System.

Solution Overview

The Sigmafine Extension for LNG (liquefied natural gas), LPG (liquefied petroleum gases and NGL (natural gas liquids) enables the transformation of inventory and custody transfer information from actual conditions to standard conditions using the appropriate volume correction factors specified by international standards and best practices. This Extension implements accurate temperature and pressure corrections for LNG, LPG and NGL mixtures. With this Extension, there is no need to create and maintain complex Excel spreadsheets or to use standalone engineering tools since all logic and computation is performed within the Sigmafine model. A combination of equations of state and correlations used by this extension addresses the reporting and monitoring needs for liquified gases in the oil and gas industry.

This Sigmafine App enables the creation of real time inventory reports using the same standard across the company, facilitating benchmarking between sites. Engineers and plant managers have now actionable inventory information and material transfer information. This results in better tracking on inventory and transfers in real time, regardless of changes of operating conditions, enabling optimized planning and scheduling.

Solution Approach

The Sigmafine Apps for LNG, LPG and NGL installs as a Data Reference in the OSIsoft PI System Asset Framework (AF) and can be configured to handle calculations based on input tags coming from the PI system.

Supporting Documents



  • Handles Multicomponent Mixtures LNG, LPG and NGL
  • Evaluates coeficients required to calculate volumes at STP
  • Uses the Klosek McKinley equation of state to calculate the gross calorific value and density of LNG
  • PI System Access (PSA) License
  • PI Asset Framework 2016 and above


  • Consistency in the creation of inventory and transfer reports
  • Optimization of the planning and scheduling due to the more accurate inventory and transfer informaiton

Solution Type

Advanced Analytics, Energy Management, Process Optimization


  • Chemical & Petrochemical
  • Mining, Metallurgy & Material
  • Oil & Gas
  • Power Generation
  • Pulp and Paper

Business Impacts

Optimize Processes


Applications for the PI System