Page 264 - Geology and Geochemistry of Oil and Gas

MODELS OF STATIC GEOLOGIC SYSTEMS 229

Fig. 11.12. Correlations between properties of the Productive Series reservoir rocks of Azerbaijan (after
Buryakovsky et al., 1986). 1 – Baku Archipelago and South Absheron Offshore Zone, 2 – Lower Kura
Depression.

stability, i.e., they are controlled by geological factors. The relationships between the
surface activity parameters of rocks and their porosity and clay content (Q 100 and
A da vs. f, C sh and Z curves) and their relationships between each other (Q 100 vs. A da ,
and f vs. C sh and Z) are very useful in petrophysical practice.
Sixteen correlations between variables (reservoir-rock properties and surface ac-
tivity parameters) are presented in Table 11.5. All these equations can be generalized
as the following single model:

F i ðyÞ ¼ a i þ b i f ðx i Þ þ c i cðx i Þ (11.32)
where a, b, and c are the empirical coefficients.
Besides these equations, several empirical relationships were developed for the
entire Productive Series of Azerbaijan. Relationships between the permeability, k,
and clay content, C cl , for various types of rocks are as follows:
Sand and silt : lg k ¼ 7:0 0:222C cl
Clayey silt : lg k ¼ 7:5 0:182C cl
Chlidolite : lg k ¼ 3:8 0:200C cl