Abstract

 
 
 Porosity and water saturation are among the important reservoir parameters in terms of reservoir monitoring which in turn are necessary for placement of future production wells. Amplitude versus offset (AVO) modelling and analysis technique have been utilized for quantitative interpretation of porosity and water saturation. For AVO modeling, Gassmann fluid substitution model in connection with 2D seismic angle gathers were used for reservoir monitoring over Sawan-4 and Sawan-7 wells. AVO modellingresults showed significant increase of density log by substituting gas by water, moderate increase of P-wave velocity and no change in S-wave velocity. Moreover, AVO modelling proved a strong relationship between porosity and reflection amplitude for all offset ranges. The class IV anomaly was evident for all porosities down to 5%. From fluid substitution modelling it is evidentthat changes in water saturation do not change the AVO effect significantly which further substantiate by investigation of pre-stack time migration (PSTM) gathers verifying the modelling results. The amplitude relationship between Sawan-4 and Sawan-7 is close to the modelled result. The amplitude and the AVO behaviour indicate lower porosity or significantly reduced sand thickness in the vicinity of Sawan-4 and Sawan-7 wells.
 
 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
