ARCHITECTURAL FACIES DISTRIBUTION ANALYSIS OF E-22 ZONE, UPPER CIBULAKAN FORMATION IN E FIELD NORTH WEST JAVA BASIN

• Main Author: REZA AYU MASARDI (NIM: 22015016), KIKI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/28491
• Institution: Institut Teknologi Bandung

<p align ="justify">E field, which is located in the North West Java Sea has been the target of exploration since of E-1 exploration well which was found in 1969 and has been in production since 1971. The produced hydrocarbons are generally derived from Upper Cibulakan Formations that aged between Oligocene to Middle Miocene. Since 2001, E field has been classified as a mature field and the field’s production has decreased / naturally declined that needs water injection activities at existing reservoirs as reservoir pressure maintenance to increase production. Water injection will be focused on several reservoirs sandstone formations of Upper Cibulakan, i.e. one of which is the E-22 Zone. Geological understanding of the detailed facies reservoir formations is indispensable as a reference in conducting the activity of water injection. By analyzing the architectural facies, it is expected to increase ability in describing the character of facies in Zone E-22 and generating models of the deposition in order to identify reservoir connectivity. To identify models of depositional environments of E-22 Zone Upper Cibulakan Formation in E Field, we use primary data consisting of well data, seismic data, and core data. Lithofacies analysis using observed data of core rock shows that there are four facies in Zone E-22 Field E, namely facies laminated mudstone (Fl), cross bed or planar sandstone facies (Sp), parallel or horizontal laminated or structure less sandstone facies (Sl), parallel or low angle laminated sandstone facies (Sh), and deformed laminated sandstones facies (Sd). Combination of this five facieses form a repetitive pattern architectural facies which associated as sand bar (SB) and lowstand deposit (LSB). Electrofacies pattern analysis compiled by the seismic analysis indicates that SB is a shelf ridge deposited on a shallow marine environment Geological reconstruction at the time of the deposition zone E-22 Field E indicate that Zone E-22 was deposited where there was an increase in sea level and was deposited shelf ridge axis with the axis North north east-south south west. Decline in sea levels afterward, causing forced regression, and forming low stand deposition from west to east<p align ="justify">