%0 Journal Article
%T PRESSURE AND PRESSURE DERIVATIVE ANALYSIS FOR NON-NEWTONIAN PSEUDOPLASTIC FLUIDS IN DOUBLE-POROSITY FORMATIONS
%A Freddy-Humberto Escobar
%A Angela-Patricia Zambrano
%A Diana-Vanessa Giraldo
%A Jos¨¦-Humberto Cantillo-Silva
%J CT&F - Ciencia, Tecnolog¨ªa y Futuro
%D 2011
%I Instituto Colombiano del Petr¨®leo (ICP) - ECOPETROL S.A.
%X ABSTRACT Non-Newtonian fluids are often used during various drilling, workover and enhanced oil recovery processes. Most of the fracturing fluids injected into reservoir-bearing formations possess non- Newtonian nature and these fluids are often approximated by Newtonian fluid flow models. In the field of well testing, several analytical and numerical models based on Bingham, pseudoplastic and dilatant non-Newtonian behavior, have been introduced in the literature to study their transient nature in porous media for a better reservoir characterization. Most of them deal with fracture wells and homogeneous formations. Well test interpretation is conducted via the straight-line conventional analysis or type-curve matching. Only a few studies consider the pressure derivative analysis. However, there is a need for a more practical and accurate way of characterizing such systems. So far, there is no methodology to characterize heterogeneous formation bearing non-Newtonian fluids through well test analysis. In this study, an interpretation methodology using the pressure and pressure derivative log-log plot is presented for non-Newtonian fluids in naturally fractured formations. The dimensionless fracture storativity ratio, omega, and interporosity flow parameter, lambda, are obtained from characteristics points found on such plot. The developed equations and correlations are successfully verified by their application only to synthetic well test data since no actual field data are available. A good match is found between the results provided by the proposed technique and the values used to generate the simulated data. RESUMEN Los fluidos no Newtonianos se usan a menudo en varios procesos de perforaci¨®n, trabajo a pozos y actividades de recobro mejorado. La mayor¨ªa de los fluidos de fracturamiento inyectados en los yacimientos que contienen hidrocarburos se comportan no Newtoniamente y, sin embargo, estos fluidos com¨²nmente se representan en los modelos como modelos fluidos Newtonianos. En el campo de pruebas de presi¨®n, se han desarrollado varios modelos num¨¦ricos y anal¨ªticos que tienen en cuenta el comportamiento no Newtoniano Bingham, pseudopl¨¢;stico y dilatante, para estudiar la naturaleza transitoria de estos fluidos en una mejor caracterizacion del yacimiento. Se han propuesto varios modelos numericos y analiticos para estudiar el comportamiento transitorio de los fluidos no Newtonianos en medios porosos. La mayor¨ªa de ellos tratan pozos fracturados y formaciones homogeneas y la interpretacion de los datos de presion se conduce mediante el metodo convencio
%K Coeficiente de almacenaje
%K Flujo interporoso
%K Comportamiento de flujo
%K Ley de potencia
%K Doble porosidad
%K Coeficiente de armazenamento
%K Fluxo interporoso
%K Comportamento de fluxo
%K Lei de pot¨ºncia
%K Porosidade dupla
%K Fracture storativity
%K Interporosity flow
%K Behavior index
%K Power-law
%K Double-porosity
%U http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-53832011000100004