New method of analyzing the pressure behavior of a well near multiple boundary systems

The accuracy of well test data interpretation is critical in obtaining several reservoir properties, such as permeability, porosity, drainage area, and well location. Well test analysis can be complicated by wellbore storage, skin, and especially by the presence of flow or no-flow boundaries in the system. Therefore, different methods for interpretation of the effects of reservoir shape and well location on wellbore pressure have been presented in the petroleum literature. Starting with the use of the image method and conventional semilog interpretation technique developed in the 1950's, well testing analysis techniques have progressed rapidly by the introduction of the pressure derivative approach in 1976. The present study uses two analysis techniques for interpreting the pressure and pressure derivative behavior for a well in multiple boundary systems, including wellbore storage and skin effects1. First, a type-curve analysis is performed using computer generated type-curve plots for different reservoir shapes and boundaries, such as (1) Well between two intersecting boundaries; and (2) Well between two parallel boundaries. The output results of the type-curve analysis are then used to develop a comprehensive technique of analyzing the well test data without type-curve matching, based on the Tiab's Direct Synthesis Technique¹⁸.