Abstract

In case of hydrocarbon production optimization it is essential to know the relationship between the inflow rate and the performance of a perforated production well. It describes the flow rate at the bottom of the well in function of the applied drawdown pressure. The process is strongly influenced by the perforation parameters, formation characteristics and the properties of produced reservoir fluids. The correct calculation gives optimum perforation design and optimized fluid production.

In a cased and perforated well, the reservoir fluids flow through the perforation channels before entering into the well. Thus the parameters of the perforations like penetration depth, phase angle, length of perforated interval, entry hole diameter, average radius of perforation channels and the radius of the crushed zone, etc. have significant impact on the relationship between the flow rate and the well performance. The very first examinations on this phenomenon dates back to the mid 70's. Several equations have been developed to describe the pressure drop through the perforation. However, numerous assumptions have been applied in the derivations of these equations, which have resulted significant loss in accuracy. A new calculating method has been derived and presented in this paper by applying the most accepted methods, i.e. the equation of McLeod and the one of Tariq and Karakas.

The new complex method takes all of the perforation parameters and their effects into account to provide more accurate results. The effect of different perforation parameters on the productivity of oil and gas producing wells are also demonstrated.

As this method takes all the effects of perforation parameters into consideration, different perforation designs can easily be compared and optimized. The great advantage of this method is that it points out the difference between effects regarding the inflow performance of oil and gas wells.

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