For the development well, because of the long production time,
the original state can not be obtained, so the first stage of the test should be pressure
recovery. Through the pressure recovery of the first stage, the pressure drop funnel before
the first stage shut-in can be inverse-derived approximately, and the pressure history can
be calculated according to this pressure drop funnel.
In the calculation of the pressure history of the lifting well,
because the lifting time is very small compared with the recovery time, the lifting time is
ignored in the wellbore pressure calculation, and it is considered that the pressure changes
instantly, that is, the pressure changes during the lifting period are step changes, and the
pressure changes during the shutdown period can be considered as DST flow, it can calculate
the recovery automatically (of course, the user can also input). For inter-pumping oil
exploitation, because the amount of formation flowing into the wellbore is not equal to the
amount that extracted from the wellbore, it is necessary to input the flowrate when the flow
reaches stable, meanwhile, the stable flow time should be confirmed.