Integrating simultaneous pre-stack inversion and well dataset for lithofacies discrimination utilizing target correlation coefficient analysis in one of Persian Gulf Iranian oilfields

Lithofacies identification play key roles in illumination of reservoir properties and reducing the uncertainties associated with the hydrocarbon reservoir characterization. In this study, prestack Poisson impedance inversion (PI) and Poissondampening factor (PDF) attributes are used to identify lithofacies and discriminate zones with different sand quality in Ghar reservoir in an Iranian oilfield. The C-value corresponding to the maximum correlation coefficient for gamma ray is used to compute PI attribute. To estimate an accurate C-value, target correlation coefficient analysis (TCCA) is used. A cross plot of the PDF and PI is used to evaluate zones with different sand quality in Ghar reservoir. Results based on lithology cut-off showed samples with low values of Poisson impedance (<۷۰۰ (m/s*g/cc)) are indicative of a clean hydrocarbon sand zone. In the zone of interest, high values of PDF (>۰.۰۰۰۳۵ ((m/s)/m*(cc/g))) and low values of PDF (<۰.۰۰۰۲۸ ((m/s)/m*(cc/g))) are indicators of high- and low-quality sand, respectively. Using a PDF vs. gamma-ray cross plot, four classifications of lithofacies are identified at well locations (clean hydrocarbon zone, shaley sand zone, sandy shale zone, and shale zone). The results also revealed a northwest-southeast channel and a hydrocarbon zone in the northwest of the studied area. The described approach will help to locate new sites for drilling future in-fill wells in areas where there is no well control.

کلیدواژه ها:

Lithofacies identification ، Poisson impedance inversion ، target correlation coefficient analysis ، hydrocarbon zone.