THE 3 rd INTERNATIONAL SCIENTIFIC CONFERENCES OF STUDENTS AND YOUNG RESEARCHERS dedicated to the 99
th
anniversary of the National Leader of Azerbaijan Heydar Aliyev
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to divide the conductive fluid in the volume of total porosity into two types of
water: free and bound. The first type of conductive fluid is free water in the
pore space (identical to water in the Archie-Dakhnov equation in its
resistivity). The second type of fluid is DEL water (double electric layer),
associated with the presence of clay minerals.
In this study, the proposed methods for calculating water saturation,
namely Simandoux, Dual Water and the Indonesian model, are analyzed
using the example of well log data from the Bulla-Deniz field [5,6]. The results
obtained were compared with water saturation according to the Archie
equation, as well as with the results of core analysis for the formation under
study. Figure 1 shows a plate for one of the wells of the Bulla-Deniz field with
the calculated curves of the water saturation coefficient. Well logging data
such as GR, NNL and resistivity logs were used as input for interpretation.
First, shale content was calculated by GR log and porosity by the neutron
method. Further, using the resistivity log and the corresponding coefficients
(a, m, n, Rw, Rwb and Rshl) in the applied models, water saturations were
calculated using the indicated methods. Note that the critical value for
assessing the saturation nature of reservoirs Sw is 0.5.
Fig.1. Plot with the results of calculations Sw according to different models
As a result of the analysis in the section of the studied well, a total of 17
productive reservoirs were identified with an effective thickness of 1.3 to 11.2
m were identified. Further, the calculated values of the water saturation
coefficients were compared for the selected reservoirs along the V and VII
horizons, with which the main hydrocarbon deposits are associated (Fig. 2).
As can be seen from the comparative analysis, the Sw values vary from 0.38
to 0.47 for horizon V and from 0.33 to 0.37 for horizon VII.