Applying of clustering for petrofacial analysis on the example of the field in Zagros province

Abstract

It is known the interest to carbonate fields is getting stronger. At the same time requirements of comprehensive approach to investigation for such fields are increased. Usage of typical metods of logs interpretation for carbonate formations can cause a high level of uncertainty in future. The main ghoal of petrophysics in terrigenous formations is geological while in carbonate formations petrophysics strongly influence on reservoir engineering. Significant heterogeneity in vertical and lateral directions increase the number of petrophysical parameters. Neglecting of these parameters can cause failure in yield achievement. There are three problems appeared during the field development became reasons for this work: 1. First problem connected with significant vary in wells yield (from 200 m³/day to 2000 m³/day). It is known facial analysis of carbonate formations is a complex problem due to different secondary processes. Therefore the next ghoal was set – try to find regularity in logs data. 2. Typical approach to net thickness estimation by porosity cut-off criteria had mistakes, thus, don’t suit for carbonate formations. The perforation of non-reservoir by logs interpretation was held relying on master log. As the result well inflow was increased. 3. The last problem was connected with intensive fall of reservoir pressure. Taking into account depletion regime of field development the reservoir pressure is a crucial parameter.