Petrophysical Variability, Fluid-Flow Behavior, and the Implications for Analysis and Modeling of Carbonate Reservoirs

Jim Jennings
Shell International Exploration and Production Houston, Texas ([email protected])

Abstract

Matrix petrophysical properties in most carbonate reservoirs exhibit a high degree of spatial variability over a wide range of scales. This variability creates a unique set of challenges in the analysis and modeling of these reservoirs. Although no two carbonate reservoirs are exactly alike, we can make some useful generalizations about their spatial variability, the resulting effects on fluid flow, and the implications for data analysis and modeling. This insight does not produce a single simplified modeling “recipe” adequate for all carbonate settings, but it does lead to some fundamental principles that can be very helpful in anticipating problems, avoiding pitfalls, and selecting appropriate analysis and modeling methods for each individual carbonate reservoir.

In this presentation I will summarize some of the most useful generalizations concerning carbonate matrix petrophysical variability and fluid flow obtained from research at the University of Texas Bureau of Economic Geology. Then, I will outline some data analysis and modeling principles that follow from this insight. These generalizations and principles are primarily derived from outcrop and subsurface studies of shallow-water platform carbonates in West Texas (Permian) and the Middle East (Cretaceous), but many of the ideas apply to other settings as well.

AAPG Search and Discovery Article #90086 © 2008 AAPG Foundation Distinguished Lecturer Series 2008-2009