ADAPTATION OF A COMPOSITIONAL PVT-MODEL FOR A GAS CONDENSATE RESERVOIR UNDER UNCERTAINTY OF INPUT DATA
Keywords:
compositional modeling, PVT properties, C5+ fraction, Peng Robinson equation of state, retrograde condensation, Whitson correlation, pseudocomponents, Pedersen correlations.Abstract
This paper addresses the modeling challenge for the Severny
Mubarek field caused by limited legacy PVT data: in a number of archived reports, the
reservoir gas composition is presented in an overly aggregated form (as a C5+ fraction),
which leads to significant calculation errors in reservoir simulation software. Based on
the proposed methodology, mathematical splitting of the heavy C5+ fraction into
pseudocomponents was performed using the Whitson correlation, which relies on a
three-parameter gamma distribution. Critical properties for each pseudocomponent
were calculated using Pedersen correlations, followed by tuning of the Peng–Robinson
equation of state. As a result, the model reproduces the dew-point pressure with high
accuracy (99.6%, calculated value 242.9 bar vs. actual 243.9 bar), improving the
reliability of gas and condensate production forecasts and supporting more robust field
development planning.
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