Seismic Data Conditioning for Accurate Well Tie Analysis and Seismic Inversion for Reservoir Properties Identification of Kadanwari Area, Middle Indus Basin, Pakistan

Abstract

Kadanwari area lies 350km Northeast of Karachi. Well-to-seismic tie analysis was performed on data (Seismic Data and well logs) provided by LMKR for correct identification of lithology, wavelet extraction for generating accurate synthetic and for acoustic impedance inversion. The adaptative technique was used for performing the well tie on E-sand interval of the Lower Goru Formation of the Cretaceous age. The adaptive technique comprises of integration of Sonic log for depth to time conversion, synthetic generation, and determination of the cross-correlation function by cross-correlating the synthetic with seismic data for wavelet extraction. The three wells namely Kadanwari 03, 10 & 11 gave a correlation of about 0.607, 0.714 and 0.77 respectively. The wavelet extracted had the dominant frequency of about 27 Hz with phase shift of 100 degrees, the same was used for inversion to the p-impedance. Elastic properties cross-plots were not significantly helpful in differentiating among the lithologies which were defined on the basis of cut-offs. 2-D correlation of properties among the three wells conform to the behavior of the fluid containing sands. Low Frequency Model was generated for incorporation in the inversion results. The p-impedance inversion showed that in the horst and graben structured Kadanwari area, the eastern block containing wells K-10 and K-11 exhibited low impedances as compared to the western block comprising of well K-03. The North eastern block showed good decrease in impedances which is recommended for further exploration on the basis of the study performed and available data.