ROCK PHYSICS MODELING FOR ESTIMATING PHYSICAL PARAMETERS TO CHANGES IN CO2 GAS SATURATION AND DETERMINING RESERVOIR QUALITY IN MUDA FORMATION, “HD” FIELD, WEST NATUNA BASIN

• Main Author: DEWI - NIM: 12314030, HARITSARI
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27737
• Institution: Institut Teknologi Bandung

<p align="justify">Carbon Capture and Storage (CCS) is one of the global warming mitigation technologies by reducing CO2 emissions in the atmosphere. This technology is a sequence of process executions related to each other, ranging from the separation and capture of CO2 (capture), transporting CO2 caught to the storage (transport), and storage to a safe (storage). In CO2 storage process, appropriate selection of reservoir layers and subsurface monitoring is required to be safely injected. Reservoirs formed in deltaic facies do not always have good qualities such as clean sand, so we need a way to see the tendency of physical parameters to the presence of clay. This study uses rock physics modeling to see the behavior lithology of clean sand and shaly sand from physical parameters measured. In the clean sand case, Nur model and Lee model are used as a reference to determine the good quality reservoir based on critical porosity (&#120593;&#119888;) and consolidation factor (&#945;). Whereas in the shaly sand case a dispersed shaly sand model was used using the Hertz-Mindlin and Hashin-Strikman Lower Bound (HSLB) formulations. Nur model on the clean sand condition gives a critical porosity value which is almost the same as the critical porosity obtained from the shaly sand modeling. While the consolidation factor in clean sand condition ignore the existence of clay content, it can becomes misleading concept about loose and compact material, also permeability of the rock. After obtaining the appropriate storage layer, we monitor the saturation of the injected CO2 gas with various saturation models. There are two saturation models that are used, homogeneous (uniform) and heterogeneous (patchy) saturations that use Brie's equation. Then the sensitivity test was carried out on several physical parameters such as density, Vp, Vs, Vp / Vs, and acoustic impedance and also detected CO2 gas through Amplitude Versus Offset (AVO) seismic response. The parameter with the best sensitivity as CO2 gas increases is density.<p align="justify">