An overview of 20 years’ hydrocarbon exploration studies and findings in the Late Cretaceous-to-Tertiary onshore Central Sarawak, NW Borneo: 1997–2017 in retrospect

摘要: An overview and integration of key petroleum exploration findings in the onshore Central Sarawak Basin, NW Borneo last 2 decades is presented. Findings revealed that critical moments for generation preservation hydrocarbon may be found Early Oligocene, Miocene, Late Miocene times. Geochemical data ninety-five (95) source rocks suggest TOC values 1.54 wt% (Miri Formation) to 70.00 (Nyalau with promising S2 S2/S3 ratios. TMax fell below 435 °C maturation threshold. Reservoir facies Nyalau, Belait, Lambir formations their subsurface equivalents have moderate-to-poor poro-perm properties. plays area are Oligocene–Miocene clastics limestones Cycles I, II, III, IV. Significant diagenetic modification evident analogue reservoir sandstones, could constitute major control units. Observed predominance structural related traps gleaned from seismic a reflection paleotectonic (Sarawak orogenic) event (ca. 40 − 36 Ma) associated region. Shale overlying possible reservoirs observed juxtaposition units against impermeable beds provide seal integrity. Deeply seated faults potential conduits, addition buoyancy. Concentration future research efforts on petroleum/basin modeling assessment was further improve current understanding under-explored Sarawak.