CONVENTIONAL PRESSURE ANALYSIS FOR NATURALLY-FRACTURED RESERVOIRS WITH NON-NEWTONIAN PSEUDOPLASTIC FLUIDS

• Main Authors: Andrea Martinez, Diana María Silva, Freddy Humberto Escobar Macualo
• Format: Article
• Language: Spanish
• Published: Universidad Industrial de Santander 2013-06-01
• Series: Revista Fuentes El Reventón Energético
• Subjects: Non-newtonian fluids; Naturally-fractured reservoirs; Conventional technique.
• Online Access: https://revistas.uis.edu.co/index.php/revistafuentes/article/view/3611/3797

Conventional oil reserves are coming to an end, then, some unconventional sources, such as heavy oil, are being the aim of oil companies. Most of heavy oils, drilling fluids and fracturing fluids behave as non-Newtonian and these fluids are erroneously approximated by Newtonian fluid flow models. Currently, there are no mathematical expressions for the application of the straight-line conventional analysis method for the interpretation of pressure tests in heterogeneous or naturally-fractured occurring formations (dual porosity) which are saturated by a non-Newtonian pseudoplastic fluid. The literature includes an analytical solution for predicting the behavior of the pressure in dual porosity reservoirs containing a non-Newtonian fluid; this solution was subsequently used to interpret the well-pressure data using the pressure and pressure derivative log-log plot without employing type-curve matching. None commercial software includes up to date such analytical solution. Several expressions to complement the conventional straight-line method are presented in this work so pressure tests in naturally fractured reservoirs with a non-Newtonian power-law fluid can be interpreted. This is accomplished mainly by estimating the interporosity flow parameter and dimensionless storage coefficient. The developed equations were successfully tested using well pressure tests reported.