A Material Balance Equation for a Sour Gas Reservoir

The gas reservoir with high content of H2S is a special type of reservoir. With the decreasing of temperature and pressure, elemental sulfur may precipitate and block pore. The conventional material balance equation of common gas reservoir takes no account of the sulfur deposition. It is difficult to scientifically describe the performance of sour gas reservoir. Mol balance principle is used to establish material balance equation in sour gas reservoir. The modified material balance equation can be used to analyze the effects of deposited sulfur on original gas in place. For the different types of gas reservoir, such as constant-volume gas reservoir and water invasion gas reservoir, the material balance equation with high content of H2S is deduced and an example is presented to compare it with the conventional volume balance equation. This new model improves sour gas-engineering theory.