Definition:
Reciprocal Productivity Index
Subject Area 1:
Production Engineering
Remarks:
Well Testing (was first coined by J. W. Crafton. It is the Rate Normalized Pressure dP/dQ (which has the units of a reciprocal PI), but Crafton recommended plotting versus Elapsed Time in the case of noisy production data, where the use of the standard superposition theory might produce an erratic Time Function.