Name: MARINA DUARTE MOSCKEM
Type: MSc dissertation
Publication date: 07/06/2017
Advisor:

Name	Role
ROGÉRIO RAMOS	Advisor *

Examining board:

Name	Role
EUSTAQUIO VINICIUS RIBEIRO DE CASTRO	External Examiner *
ROGÉRIO RAMOS	Advisor *

Summary: It’s common for regulations to require natural gas flow measurement
to be reported on a volumetric basis. Therefore, the measurement
should also be reported at a specific pressure and temperature,
referred to as standard conditions. In Brazil, petroleum and gas
measurements must comply with ANP/Inmetro Ordinance
01/2013, which states the following standard conditions: 1 bar,
20°C. When the flowing conditions are not the same as the
standard ones, the measurement must be corrected for the
standard condition by means of thermodynamic Equations of
State – EOS. Thus, the measurement reported in the standard
conditions carries a portion of uncertainty relative to this operation,
whose value depends on the temperature and pressure, as well as
on the chosen EOS. The main goal of the work is to evaluate this
parcel of the uncertainty, especially in critical flowing conditions.
Some typical natural gas compositions were selected and the
following flowing conditions: 50 bar, 4°C. Results obtained by
means of Monte Carlo simulation show that the measurement
reported at the standard conditions carries a portion of uncertainty
generally greater than 1,0 percentage points, only due to the
necessary correction just commented. It’s a significantly high value,
especially if we take into account that Brazilian regulation states a
maximum of 2% for fiscal measurements, for example.

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