Abstract
Integrated Amplitude Versus Offset ( AVO), elastic seismic inversion and petrophysical analysis have been successfully applied to estimate the elastic parameters of the reservoir for a case study of the gas field in south Sumatera basin. This paper aims to have better understanding the petrophysical properties of the reservoir. The petrophysical analysis was carried out by performing routine formation evaluation that includes calculation of shale volume, porosity, and water saturation of basic well log data. Sensitivity analysis was conducted to evaluate the sensitivity parameters of the log for changing in lithology, porosity, and fluid content in the reservoir. For completing the availability of elastic parameter from well log data, shear wave logs were derived from Castagna’s mudrock line relationship. Further, P-impedance, S-impedance, VpVs ratio, LambdaRho (λρ), MuRho (μρ) and density(ρ) were then calculated through a Lambda-Mu-Rho (LMR) transformation. Prior to performing AVO analysis and elastic seismic inversion, super gather technique was applied to improve the reliability of pre-stack seismic data. Elastic seismic inversion was carried out to extract the lateral elastic properties to capture lithology and fluid changes in the reservoir. In addition, AVO analysis of pre-stacked data was applied to identify hydrocarbon-bearing sandstone at target zone. The petrophysical analysis shows that porosity versus density crossplot is able to distinguish sand-shale based on 34% shale volume cutoff, while LMR crossplot is able to delineate hydrocarbon zone at water saturation value under 65%. The predicted lateral elastic parameter shows slightly higher value compare to overlying layer.
Highlights
There have been numerous optimization strategies has been performed to enhance the productivity of the old producing field of south Sumatera basin
The integrated Amplitude Versus Offset (AVO), elastic seismic inversion and petrophysical analysis is the purposeful strategy for performing rock physics analysis, which is calibrated by laboratory and well measurements and continued to the advanced seismic data processing
The study area is focused on Talang Akar Formation of south Sumatera basin, which is a Tersier back-arc basin located along west to south part of Sunda land
Summary
There have been numerous optimization strategies has been performed to enhance the productivity of the old producing field of south Sumatera basin. The integrated Amplitude Versus Offset (AVO), elastic seismic inversion and petrophysical analysis is the purposeful strategy for performing rock physics analysis, which is calibrated by laboratory and well measurements and continued to the advanced seismic data processing. A petrophysical analysis that includes shale volume, p-ISSN: 2541-3384 e-ISSN: 2541-3392 porosity, and water saturation was performed to identify hydrocarbon bearing zone at the targeted interval. Petrophysical parameters that can be directly correlated to seismic data is a primary (P) and secondary (S) wave. In this case, P-wave was obtained from a sonic log, while S-wave was derived from Castagna’s mudrock line relationship. The Lambda-Mu-Rho crossplot gives insight to hydrocarbon presence in reservoir since LambdaRho is the incompressibility expression can be used to predict pore fluid content, while Mu-Rho is rigidity term that related to lithology [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
