A Comprehensive Pressure Distribution Model for Horizontal Well in Bottom-Water Reservoir

Abstract

The growing application of horizontal well technology provided far-reaching solutions to more realistic phenomena in well test analyses. However, existing models restrict the types of flow regimes by assuming that the dynamics of fluid are controlled by the geometry of the reservoir only. Such an assumption limits the number of flow regimes and hence the accuracy of well test analyses. In this article, all potential flow regimes of a horizontal well in a reservoir supported by bottom water were considered. The conceptual model assumed that the dynamics of the reservoir fluid are a function of the petrophysical properties of the reservoir, the properties of the fluid, and the geometry of the reservoir system. The physical model and the mathematical model were developed based on the conceptual model. The mathematical model is the pressure distribution of the horizontal well in the reservoir. The pressure distribution is in the form of dimensionless pressure and dimensionless pressure derivative functions of reservoir system properties, fluid properties, reservoir system geometry, and dimensionless time. Results of the study show a series of flow patterns along the principal axes or along combinations of the principal axes. Each flow regime could be distinguished by one of the flow patterns and the axes of orientation of the pattern. Each flow regime could be recognized by its characteristic signature in the log-log graph plots of the pressure distribution.