Transient Well Testing

Transient well tests measure changes in reservoir pressure associated with changes in well rates. Measurement and analysis of the time‐dependent pressure response can provide information about reservoir structure and the expected flow performance of the reservoir. Transient well tests often motivate changes in the way the well is operated or the field is managed. This chapter discusses a selection of transient well tests for oil wells and gas wells and illustrates how transient well test information is used. The pressure transient testing (PTT) method relies on measuring the changes in pressure at the wellbore as a function of time that accompany fluid flow rate changes in the wellbore. Gas flow rate is changed, and the resulting change in pressure at the well is recorded as a function of time. Results of gas well PTT can be used for two purposes: to determine reservoir characteristics and to determine gas well deliverability.