ION MALUREANU
Universitatea "Petrol-Gaze", Ploiesti
POSSIBILITIES FOR MODELLING THE VARIATION OF THE RESISTIVITY IN THE INVADED ZONE OF THE REZERVOIR.
IMPLICATIONS IN THE EVALUATION OF THE FORMATIONS WITH GEOPHYSIC DIAGRAPHY
(ABSTRACT)
In principle, the mud is kept at a slightly higher pressure than the formation
pore-fluids. Because of this pressure difference there is a tendency for the
mud to infiltrate porous, permeable beds. The mud-filtrate displaces some of
the formation fluids. The reservoir rock near the hole does not contain the
same fluids as before invasion. Changes have occurred both in the nature of
the fluids and the reservoir rock properties.
This paper presents new models of the invasion fluid distribution between the
flushed zone of resistivity, 
io,
and the virgin reservoir of resistivity, R,
for a given mud-type.
The models can be used for better results of log interpretation.
Key words: invasion, zone of invasion, resistivity, diameters of invasion,
zone of resistivity, mud, mud-filtrate.