Well-test-analysis and Applications of Source Functions in a Bi-zonal Composite Gas Reservoir

Abstract

Permeability is one of the most important petrophysical parameters in the design of reasonable portion of production, but is the most difficult to obtain. It is vital to predict the value of permeability correctly for which has a significant effect on the oil/gas recovery. Well test analysis is a dynamic method to recognize the characteristics of reservoirs including permeability. According to the seepage problems of high condensed fluid, the continuous point source functions in bi-zonal gas reservoir under three kinds of boundaries are presented by constructing function method, which are useful but reported rarely. Physical models and pressure responses of fully/partial penetrating vertical well in bi-zonal composite reservoir are obtained on the basis of the source functions. Type curves of the wells are plotted through the Stehfest numerical inversion and the flow periods are analyzed. The authors validate their approach with a field case and demonstrate its application.

Keywords:

• bi-zonal composite reservoir
• gas reservoir
• point source function
• well testing theory