CARBONATE RESERVOAR CHARACTERIZATION OF TOMORI FORMATION BASED ON PETROPHYSICAL ANALYSIS IN SRIKANDI FIELD, BANGGAI BASIN OF CENTRAL SULAWESI

• Main Author: Anastasia, Sartika
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/71280
• Institution: Institut Teknologi Bandung

Srikandi Field is located on the offshore Toili Block Area, south of Banggai Basin. This field has been proven to produce oil and gas from carbonate reservoar of Tomori Formation. Srikandi Field has a complex tectonic condition which is an imbricated thrust fault structure, therefore has affect fracture development on this field. Generally, carbonate reservoar has a non linear relationship between porosity and permeability that caused by high heterogeneity. The deposition of carbonate and process afterward give significant influence for correlation between porosity and permeability. Therefore, analysis of carbonate reservoar characteristics and secondary porosity in the Tomori Formation was carried out in the hope of supporting the development strategies in the Srikandi Field. The integration of facies analysis, diagenesis, petrophysical evaluation, petrophysical rock type (PRT) and evaluation of secondary porosity is used to identify and recognize reservoar characteristic. Facies and diagenesis analysis is used to identify depositional environment and impact on rock type. Petrophysical Rock Type (PRT) used to classify the properties of the petrophysical evaluation results. Secondary porosity method are an advance method in formation evaluation to identify value and type of secondary porosity that works in the limestone reservoar of Tomori Formation. Lithofacies analysis in limestone Tomori Formation can be classified into eight (8) lithofacies into Sekeltal Coral Wackestone-Packstone, Skeletal Foraminifera Wackestonepackstone, Skeletal Coral Algae Wackestone-Packstone, Skeletal Foraminifera Wackestone, Skeletal Foraminifera Algae Wackstone, Skeletal Miliolid Wackestone, Coral Grainstone and Coal. Based on the results of the depositional facies analysis, limestone of Tomori Formation in the Srikandi Field are associated with Patch Reef, Inner Platform Interior dan Outer Platform Interior. Diagenetic process that occur in Srikandi Field are compaction, cementation, dissolution dan fracture. From thin section analysis, it shows that the Srikandi Fields is in early to late diagenetic phase, which is Marine-Deep Burial zone. Rock property analysis has been done by flow unit identification which is by RQI (reservoar quality index) dan FZI (flow zone indicator) approaches. Each rock type shows relationship between porosity and permeability which is reflected in correlation coefficient. FZI method delivered six (6) rock types and one (1) rock type for coal. These rock type can be combined into 4 rock types (RTC) based on the type of porosity. The result of rock type be affected by the type of porosity that developed in carbonate resevoir, which is primer porosity and secondary porosity (vuggy, mouldic and fracture). The result of distribution of reservoar properties is petrophysical rock type map, porosity map and permeability map. These map expected to give contribution to further development strategies in Srikandi Field.