AVO CHARACTERISTICS STUDY AND RESERVOAR CHARACTERIZATION USING SEISMIC ATTRIBUTES AND SIMULTANEOUS SEISMIC INVERSION IN THE BINIO FORMATION AT FIELD

• Main Author: Haekal Nadhir, Fatih
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/77734
• Institution: Institut Teknologi Bandung

This final project discusses the characteristics of AVO (Amplitude-Versus-Offset) in hydrocarbon reservoirs within the Binio Formation in the X Field, Bentu Block, Central Sumatra Basin. The reservoir in this field consists of thinly layered gasfilled formations that are challenging to identify. The objective of this research is to analyze and understand the influence of fluids on AVO responses and to comprehend the factors affecting AVO characteristics. This study utilizes CDP (Common Depth Point) seismic data, average velocity data, and data from five wells. Among these wells, three lack shear velocity data, which will be predicted using multi-attribute methods and the Greenberg-Castagna approach. Each fluid possesses distinct density and bulk modulus properties, which can manifest different AVO characteristics such as intercept and gradient. Higher gas fluid saturation within the reservoir results in more negative intercepts and gradients in AVO responses, moving further away from the shale trend on AVO crossplots. The target layers in the X Field have thicknesses less than ¼ ?, but several layers can still be effectively detected by AVO. AVO performs well at detecting the top and base of layers with thicknesses up to 1/13.3 ?. Factors influencing AVO characteristics include the type and saturation of fluids filling the hydrocarbon reservoir, reservoir porosity, rock lithology in the hydrocarbon reservoir, as well as reservoir thickness and depth. AVO inversion provides superior reservoir characterization compared to classic AVO methods. AVO inversion can effectively detect thin layers that are not well-identified by classic AVO and seismic attributes. Gas distribution is centralized in the central part of X Field (layers B2a and B4a) and in the northwest part of X Field (layer B2a).