Reservoir Fluid Properties - Cased-Hole Log Analysis and Reservoir Performance Monitoring - page 35

Gas Viscosity . Gas viscosity is a function of gas gravity, temperature, and pressure.
Figure 3.17 offers a means of finding ʼ g . By way of example the gas viscosity at
well flowing conditions ʼ gwf can be found given that ʳ g = 0.70, p wf = 2,000 psia, and
T wf = 200 °F by following the steps:
1. Enter ʳ g = 0.70 chart at p wf = 2,000 psia
2. Go up to T wf = 200 °F
3. Read ʼ gwf = 0.018 cp
Fig. 3.17 Gas viscosity. Reprinted with permission of the Oil and Gas Journal (from May 12,
1949)