One of the Steady-State Diagnostics methods based on plotting pressure integral P(t) = \int_0^t \left( p_{wf}(\tau) - p_e(\tau) \right) d\tau vs cumulatives Q(t) = \int_0^t q_t(\tau) d\tau
It shows unit slope for Steady-State flow:
| (1) | P(t) = J^{-1} Q(t) |
where
J | constant productivity index |
In case pressure data is available for a fair interpolation it is recommended to plot subsurface cumulatives rather than surface which provides better linearity with pressure integral for Steady-State flow.
Although it is equally applicable to both producers and injectors, due to pressure data availability in practical cases the hall plot sought the most of its applications for water injectors.
See Also
Petroleum Industry / Upstream / Production / Subsurface Production / Field Study & Modelling / Production Analysis / SS Diagnostics