MULTIPLE RATE ANALYSIS FOR PRESSURE BUILDUP TESTS IN NATURALLY FRACTURED RESERVOIRS.

This paper presents equations for evaluation of buildup tests in naturally fractures reservoirs, when there are variations in flow rates previous to shutin. The problem has not been treated previously in the petroleum engineering literature. The reservoir is represented by (1) a stratum dual-porosity model, and (2) a dual-porosity model made out of cubes with spaces in-between. On the basis of a theory developed by de Swaan as extended by Najurieta, and a theory developed by Odeh and Selig to account for variables rates previous to shutin, equations have been developed to describe pressure behavior during a buildup in a naturally fractured reservoir.