The initial time interval of the pressure transient during which bottom-hole pressure is dominated by boundary-free reservoir flow, for example IARF (see MTR at Fig. 1)
Fig. 1. PTA Diagnostic Plot with ETR, MTR and LTR time zones. Pressure drop is in blue and log-derivative is in red. |
In small-volume reservoirs with high permeability the LTR may occur immediately after the ETR.
In some cases the wellbore storage and well-reservoir contact may extend ETR all the way up to LTR.
In these case the MTR may not be observed on PTA Diagnostic Plot.
See Also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Well Testing / Pressure Testing / Pressure Transient Analysis (PTA) / PTA Diagnostic Plot
[ Well & Reservoir Surveillance ] [ Pressure Diffusion ] [ Infinite-acting radial flow (IARF) ] [ ETR ] [ LTR ]