Page 97 - Reservoir Formation Damage
P. 97
Chapter 5
Permeability
Relationships
Summary
A review of the permeability relationships considering the formation
damage effects in petroleum reservoirs is presented.
Introduction
The permeability relationships can be classified in two groups:
static and dynamic. The static correlations have been derived using
the properties of various porous materials that have not been subjected
to formation damage processes. The dynamic correlations or models
consider porous media undergoing alteration due to rock-fluid interactions
during formation damage and, therefore, are preferred for formation
damage prediction.
In the following, selected models pertaining to formation damage are
reviewed and presented with some modifications for consistency and
applications in the formation damage prediction.
The Carman-Kozeny Hydraulic T\ibes Model
The hydraulic tubes model was derived based on the analogy between
the flow of fluids through porous media and parallel flow through a
bundle of tortuous capillary tubes (Carman-Kozeny, 1938).
The number, diameter, and the tortuous length of the hydraulic tubes
are denoted by n, D h, and L h, respectively. The porosity, specific pore or
grain surface, and length of the porous media are (|>, Z, and L. V p and V b
denote the pore and bulk volumes, respectively.
The tortuosity of porous media is expressed as the ratio of the actual
tortuous tube length to the length of porous media:
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