GPA 2145-09 Rev 1 GEQ GHV summary factors.xlsx

The Gas Producers Association, now known as the GPA Midstream Association ( ), has a issued a revised standard GPA-2145–16 – Table of Physical Properties of Hydrocarbons and Other Compounds effective 1 January 2017. This latest standard now becomes GPA Midstream 2145-16, which replaces GPA 2145-09.

The update is based on revised test methods and a merger with the physical property data within the GPA Engineering Data Book.  The update can be found here: GPA 2145 16 Publication.

A summary of the [few] changes can be found in the attached excel sheet (courtesy Al McCue). The only changes to either the G.Equiv or GHV factors is that G.Equiv factors for both hydrogen (H2) and helium (HE) changed slightly.  As these components are only present in trace quantities in most gas mixtures and are not listed on liquid analyses – these new factors should only affect gas allocations and cascade allocations very minutely, if at all.  Some of the other physical properties that did change will affect the way gas volumes are calculated by your chart reading company and inside your SCADA systems.

The new GPA 2145 incorporates both the data from the old 8 page GPA 2145-09 standard and the GPSA engineering data book. The new standard is 68 pages of constants and physical factors in both Imperial (FPS) and metric (SI) units.  The new standard can be purchased online at: GPA 2145 16 Publication.

CAPPA members should update their systems and worksheets to reflect the revised factors. These revised factors can affect calculations that are involving gas equivalent, recombined and gas volumetric and heating value allocations.  The potential systems impacted will be the Production Accounting System, Field Data Capture, Gas Volume Determination and SCADA systems. You may want to review with your production operations / production engineering and measurement group to see that changes are correctly made. If unsure how to update these factors within your internal systems, members should contact their vendor for guidance. These changes were effective for production and sales volumes from January 1, 2017 forward which starts in the PA world for reporting January’s volumes in February 2017.

Petrinex have made updates reflecting the change for the January 2017 production month cycle and their broadcast message to users can be found on the Petrinex main page: