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LABORATORY EXPERIMENT № 2

DETERMINATION OF THE EFFECTIVE POROSITY

FACTOR OF ROCK BY I.A.PREOBRAZHENSKY’S

METHOD (BY MEANS OF INSTALLATION FOR

VACUUMING IV-3 (ВУ-3) )

2.1 The objective of the experiment is: to study the concept of
effective porosity of rock and to determine the effective porosity
factor of the rock sample by means of the method of saturation of

the rock sample with kerosene by vacuuming.

2.2 Definitions

Effective porosity of rock is the volume of pores (voids) which
are linked between themselves and with outer medium (without
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isolated pores). The effective porosity of rock is measured in m , cm .
Effective porosity factor is the ratio of the volume of

interconnected pores V to the bulk volume of the rock sample
int. p.
V b.r.s. :
V
m  int. p. . (2.1)
ef.p. V
b.r.s.

I.A.Preobrazhensky’s method is most commonly used for
determining the effective porosity factor (that is the method of the rock

sample saturation with liquid, usually kerosene). According to this
method the volume of interconnected pores is determined as the

volume of kerosene filling the pore space of the rock sample after its

saturation in vacuum and the bulk volume of the rock sample is
determined by weighing the rock sample saturated with kerosene in air
and in kerosene. Thus for determining the bulk volume of the rock

sample Archimede’s law is used (the bulk volume of the rock sample

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