MASS BALANCE METHOD FOR NATURAL GAS FIELD EXPLOITATION IN DYNAMIC CONDITIONS ZASTOSOWANIE METODY BILANSU MASOWEGO DLA ZŁÓŻ GAZU ZIEMNEGO W WARUNKACH DYNAMICZNYCH

In a number of cases natural gas exploitation and operation of underground gas storages face the problem of closing wells for a time during which static pressures at wellhead and bottomhole (mean reservoir pressure) can be reliably measured. Therefore, reservoir engineering has to be involved in determining these pressures to fi nally verify the gas resources on the basis of dynamic pressure values. The methodics of determining mean pressures on the basis of measured dynamic pressures in a well is described in the paper. This methodics is based on boundary gas fl ux to the well in a semisteady state. Basing on measurements of dynamic pressures in production wells there were determined mean pressure values in reservoir, followed by evaluation of energy conditions of the analyzed gas fi eld with the „p/z” method. Afterwards, initial gas resources in the wells’ impact zones could be established. The obtained results were verifi ed making alternative balance calculations on the basis of bottomhole pressures in static conditions. The comparison of the results reveals that the presented method is fully applicable.