REGIONAL VITRINITE REFLECTANCE (Ro) TREND FOR PREDICTING KITCHEN AREA BENEATH BATUI THRUST IN THE ONSHORE AREA OF MATINDOK BLOCK, EASTERN SULAWESI-INDONESIA

摘要

Based on previous studies, there are two possible kitchen areas in Matindok Block, Eastern Sulawesi; beneath Batui Thrust Zone on the NW-W Area and the Tolo Deep as Post Collision-Foreland Basin on the E-SE Area. These kitchen areas are products of Late Miocene to Early Pliocene collision between Banggai-Sula Microcontinent and East Sulawesi Ophiolite (ESO) ― magmatic arc of Sundaland.rnThe Kitchen Area beneath Batui Thrust was mapped using gravity data interpretation. Seismic operations have not been conducted in the highly mountainous area of Ophiolite due to operational difficulties. However, Tolo Deep is well imaged using 2D offshore seismic lines. The main objective of this study is to predict which kitchen area generated hydrocarbons using Vitrinite Reflectance (Ro) Trend. Regional Vitrinite Reflectance (Ro) Trend Section and Map were made from eight wells cutting samples and Vitrinite Reflectance.rnCalculated (Rc) was obtained from condensate samples in Minahaki Formation in the Maleo Raja (MLR)-1 and Matindok (MTD)-3 Wells using Biomarker Aromatic Methylphenanthrene. Both condensate samples have Rc range from 0.9 to 1.2 (peak to late mature) but based on Ro section across eight onshore wells, maximum Ro is only 0.6 (early mature). So we can conclude that the Condesante sampled found in Minahaki Formation on both wells migrated from an area that has minimal 0.9 Ro value. Based on Ro Map, Ro trend increases toward NW Area or toward Kitchen Area beneath Batui Thrust. 2D Basin Modelling of composite seismic line from SE to NW across Senoro, Matindok, Maleo Raja Structures toward Kitchen Area beneath Batui Thrust was done to validate this Ro Trend. The 2D Basin Modelling also indicated that Kitchen Area beneath Batui Thrust has Ro Range from 0.7 to 1.2 (peak to late mature).