1. n. [Well Testing]

Testing that is accomplished by measuring pressure in the annulus, or by pulling the pump and running a pressure gauge in the hole. The preferred method is usually to measure the pressure in the annulus if no packer is present. This is best done by monitoring the rise in fluid level with an echo-sounding device and calculating the bottomhole pressure by assuming a fluid density. Several excellent devices and associated services are available. Any time a well is shut in gradually, as is the case for pumping wells, some kind of multirate analysis is usually required to obtain acceptable results.