RESERVOIR CHARACTERISTICS OF DONGGI FIELD, CENTRAL SULAWESI, USING INVERSION AND AVO ANALYSIS METHODS

摘要

Donggi Field is a gas field located in Matindok Block - Central Sulawesi. The reservoir of this field is Miocene carbonate build-up, with satisfactory porosity at almost all intervals in the area; hence, porosity distribution is not the main issue in developing this field. The objective of this study is to predict lateral and vertical distribution of the gas content reservoir, by ascertain reservoir properties of Donggi Field using seismic modeling (AVO analysis, Acoustic and Elastic Impedance). This study also shows possible upside potential of Donggi Field.Fluid content of a carbonate reservoir can best be identified using Lambda-Rho (λp) and a combination of P-impedance and S-impedance. In order to obtain reservoir properties that correlate with fluid content in Donggi wells, we do some cross-plots of all acoustic and elastic parameters, such as Porosity, P-impedance, S-impedance, Lambda (λ), Mu (μ), Rho (p), as a feasibility analysis of well data. In this study, we apply enhance seismic processing-modeling to identify rock and fluid properties, P-impedance, S-impedance and λp, which are good seismic parameters to characterize porosity and gas distribution.From the feasibility analysis, the best parameter to predict the presence of gas is λp. The gas anomaly from λp shows distribution of gas in the built-up structure to the build-up spill point. These anomalies are not present in Donggi-4 well, which confirmed the carbonate water content in this well. These gas anomalies also spread out outside of Donggi Field, such as in the middle-southern and the Northwestern areas of Donggi structure, whichwill hope increase current gas reserves in Donggi Field.