A NEW METHOD FOR PRESSURE TEST ANALYSIS OF A VERTICALLY FRACTURED WELL PRODUCING COMMINGLED ZONES IN BOUNDED SQUARE RESERVOIRS

Although hydraulically or naturally fractured wells located in stratif ied bounded reservoirs are common, reliable techniques available to an alyze the pressure test data for such reservoirs are lacking. This pap er presents a mathematical model that describes the pressure behavior of a vertically fractured well located in a stratified, bounded, squar e reservoir. The fracture can be either a uniform flux or an infinite conductivity fracture. It was found that the dimensionless pressure fu nction and its derivative and the fractional production rate from the different layers are mainly controlled by the fracture penetration int o the formation, and that transmissibility and storativity affect the fractional production rate and the pressure derivative but have little effect on the dimensionless pressure function. Type curves of dimensi onless pressure and dimensionless pressure derivative can be used to e valuate the reservoir characteristics. The selection of the appropriat e type curve is guided by the behavior of the layer fractional product ion rate obtained from flow rate survey carried out during well testin g. Type curves for uniform flux and infinite conductivity fractures ex hibit similar features. Two examples are presented to demonstrate the application of the new method of analysis presented in this paper.