Content of PetroWiki is intended for personal use only and to supplement, not replace, engineering judgment. SPE disclaims any and all liability for your use of such content. More information
Sandbox:Shallow gas zones
Shallow gas may be encountered at any time in any region of the world. The only way to combat this problem is to never shut in the well; divert the gas flow through a diverter system instead. High-pressure shallow gas can be encountered at depths as low as a few hundred feet where the formation-fracture gradient is very low. The danger is that if the well is shut in, formation fracturing is more likely to occur, which will result in the most severe blowout problem, underground blow.