The report presents a method of analysis of the pressurc build-up curve obtained from a closed-in well by olotting the bottom hole pressure against the, where 9 is the closed-in time logarithm of ~ to + 9 9 and to is the past producing life of the well.
In all cases it proves to be possible to determine the permeability of the formation from the slope of this curve.
Mehods are also given for extrapolating the recorded pressures to infinite closed-in time for the cases of I-a new well far from any reservoir boundary II-a new well close to a fault, but far from any other boundary III-a well in a finite reservoir.
Several illustrative examples are discussed.
Le rapport présente une méthode d'analyse de la courbe de remontée de pression dans un puits fermé obtenue en représentant la pression de fond en fonction du logarithme de -$- -, a étant le temps écoulé après la fermeture et to la durée de la vie productive passée du puits.
I1 en ressort qu'il est possible dans tous les cas de déterminer la perméabilité de la formation à partir de l'inclinaison de cette courbe.
On indique aussi des méthodes pour l'extrapolation des pressions enregistrées pour une période de fermeture infinie dans les cas ci-après :
un nouveau puits éloigné des limites du réser-
un nouveau puits se trouvant à proximité d'une 8 voir; faille, mais loin de toute autre limite;
un puits situé dans un réservoir limité. * N.V. De Bataafsche Petroleum Maatschappij, The Hague, Netherlands.
Plusieurs exemples donnés à. titre d'illustration sont discutés.
Acknowledgements The author wishes to state that he was not concerned with the development of the theories herein presented. They were evolved over a considerable period by the reservoir engineering section of the production department of the head office of the Bataafsche Petroleum Maatschappij in The Hague.
Among others who worked on the matters herein presented should be mentioned Messrs B. P. Boots, I;. Brons, D. N. Dietz, M. Jakobs and W. R. van Wijk *.
Contents PART I-THEORY .....
I, I-Basic Equations and Assumptions 504 I, 2-Basic Solution to the Equation of Flow ... 504 I, 3-Pressure Build-up in a Single Well in an Infinite Reservoir ............ 504 a) Constant Production Kate before Closing in 504 b) Variable Production Rate before Closing in 505 c) Interpretation of Build-up Equations V, VI, ...............
VI1 506 d) Conditions of Applicability ....... 506 Reservoir .............. 506 I, 4-Influence of a Fault in an Otherwise Infinite I, 5-Well at the Centre of a Finite Circular Reservoir 508 PART I I-AP ELI CATI O N S II, 1-Introduction ............. 510 Well 5x0 II, a-Examples of the Pressure Build-up in a New II, 3-Examples of the Pressure Build-up in a Well II, 4-Example of the Pressure Build-up in a Weil in a Finite Reservoir .......... 517 II, j-Comm
