STRUCTURAL MODEL & SEDIMENTOLOGY ANALYSIS OF THE EX CARBONATE FIELD, CENTRAL LUCONIA PROVINCE, SARAWAK

Abstract

Central Luconia Province displays various structures in different parts of the basin attributed to extensional, strike-slip, and wrench tectonics. This affected the growth of the EX carbonate platform, the heterogeneity of carbonate facies, and lithological properties variations in the EX field. Such complexities restrict the understanding of the structures and sediments and may lead to well placement problems during a development stage. This research aims to study the carbonate growth of the EX field in accordance with the structural deformation and to analyse the field’s sedimentology. Detailed research of the structures in the EX carbonate platform was done using seismic interpretation to determine the nature of the relationship between faults and carbonate formation. Concurrently, a comprehensive sedimentary analysis was conducted using core and thin section studies to interpret facies characterization and depositional environment. The spectral decomposition attribute was used to study the seismic response of the lithologies in this field by demonstrating the anomalies of the carbonate platform using frequencies ranging from 328 Hz to 356 Hz. This research contributed to the interpretation of individual faults and the generation of a conceptual growth and structural model based on a seismic, attribute, and structural interpretation. The anomalies were used to identify the EX carbonate body and features such as the rim of the build-up through the spectral decomposition attribute. The sedimentary analysis from the EX-4 well also improved facies distribution and depositional environment, ranging from a deeper lagoon to a reef environment. This research can be used as an input for further correlation studies of the Central Luconia basin at a regional scale.
 Keywords: carbonate platforms, tectonics, spectral decomposition, carbonate core