Method for testing gas wells in low pressured gas formations

摘要

The "Tank Test" method for determining well tests in low pressured reservoirs or aquifers utilizes gravity drainage from a water storage tank to inject water into the reservoir. The Tank Test eliminates the need for expensive pumping equipment and the required manual pump rate adjustments. The low costs associated with the Tank Test allows the test to run for a longer duration so that a greater portion of the reservoir can be investigated. The duration of the test and thus the radius investigation can be extended by repeatedly refilling the tank as necessary. The Tank Test also reduces the possibility of fracturing the reservoir during injection tests in low permeability reservoirs. The primary criteria for performing a tank test is that the hydrostatic head from the tank to the formation be significantly different than the reservoir pressure. In addition, the Tank Test minimizes stress effects on stress sensitive formations.