Free Gas in Place
Free gas in place, abbreviated as \(G_f\), is the total volume of natural gas that is present in a reservoir and is not dissolved in oil or water but exists in a free state. This term is used in reservoir engineering and the oil and gas industry, as it represents a measure for evaluating the potential productivity of a gas reservoir.
key Points about Free Gas in Place
- Reservoir Rock - The porous rock in which the gas is stored.
- Porosity - The measure of the void spaces in the rock, which can hold the gas.
- Gas Saturation - The fraction of the pore space that is filled with free gas.
- Reservoir Volume - The total volume of the rock containing the gas.
Free Gas in Place formula |
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| \( G_f \;=\; 7758 \; A \; h \; n \; ( 1 - S_{wi} ) \; E_{gi} \) | ||
| Symbol | English | Metric |
| \( G_f \) = free gas in place (SCF) | \(cu^3\) | - |
| \( A \) = drainage area | \(ft^2\) | - |
| \( h \) = thickness | \(ft\) | |
| \( n \) = porosity | \(dimensionless\) | - |
| \( S_{wi} \) = initial water saturation | \(dimensionless\) | - |
| \( E_{gi} \) = initial gas expansion factor (SCF/bbl) | \(cu^3 \;/\; bbl\) | - |
Tags: Drilling