Abstract
Hydraulic fracturing design is highly dependent on the knowledge of the injection fluid efficiency. This parameter is generally derived from the interpretation of the calibration tests fall offs. Two popular methods are the square root of time and Nolte's G function1,2,3,4 . Such interpretations are not always straightforward and can lead in some practical applications to the failure of propant placement i.e: a screen out with an impact on the post frac well's productivity.
In this paper a new interpretation technique for closure pressure determination is presented. It is based on a novel utilisation of Nolte's F function5 . Field cases on Algeria's In-Adaoui field are analysed. Proppant placement failures are explained. These examples demonstrate the usefulness of the F function for improving hydraulic fracturing design whether for a conventional permeabilty estimation or for closure pressure and hence efficiency determination.