The porosity derived from the

density log ([[phi].sub.D]) is defined by the following relationship (Dresser, 1979):

The modelling is based on a 1D seismic-elastic model, for which the petrophysical parameters P-wave velocity, S-wave velocity, and density are derived from sonic and

density logs of the Ktzi202 observation well [21].

In order to analyze the accuracy of porosity estimation by

density log data, we use resistivity log data and combine the Archie formula [57] to make a comparison between the estimation results, and the comparison results are shown in Figure 8.

Borehole compensated

density logs corrected for naturally occurring gamma rays.

In calibrating data sets, Gamma ray, porosity, compressional wave velocity ([V.sub.P]), Shear wave velocity ([V.sub.S]) and

density logs were displayed and analysed in the well-viewer of the RokDoc project (figure 3).

5, 1498 m and 1508 m), and the mud transgression drives the

density log value of the undisturbed formation much lower than the normal mudstone.

Total Organic Carbon (TOC) and Total Organic Matter (TOM) determined from the

density log correlates with laboratory values obtained by Petters et.

Later to confirm our calculated DT log, a synthetic seismogram is generated using calculated DT log and

density log (RHOB).

(2) Cross plot of compensated neutron log (CNL),

density log (DEN), and interval transit time log (AC) are used to identify high GR reservoir [4].

The TOC and TOM values calculated from

density log indicate that the TOC of Gongila shale exceeds the kerogen threshold of 0.5 wt% (for a potential source rock) for generation of crude oil [5 21].

Based on Gamma Ray (GR), Resistivity log (LLD),

Density log (RhoB) and self-potential log (SP) along with published literature data different, environments of deposition are assigned to the Cambrian and Lower Permian rock units.

To interpret petrophysical properties, different logs were used which include gamma ray log, neutron log,

density log, long latero log, spontaneous potential and sonic log.