PRESSURE TRANSIENT TESTING OF THE HETEROGENEOUS RESERVOIRS

Over the years, attempts have been made to include system heterogeneit ies into mathematical descriptions and to determine their effect on pr essure response. In this study, a general case of a system with layers of non-uniform thicknesses is considered. The mathematical descriptio n is based on assuming radial flow within individual layers and pseudo steady-state cross now between the adjacent layers. Since the angle of the interphasing plane may assume any angle between 0 and 90 degrees, layered (uniform thicknesses) and composite systems constitute the li miting cases. The analytical solution is found in Laplace space and th e numerical inversion to real space is obtained by using the Stehfest algorithm. The model is verified for several simpler subsystems and it s sensitivity to reservoir parameters is investigated. Solutions are p resented in a graphical form fdr a selected set of parameters. Based o n this model a method of well test data analysis is proposed.