Publications

The Banggai-Sula Foreland Basin was formed by the collision between the Banggai-Sula Microcontinent and the East Sulawesi Ophiolite (ESO) which started in Late Miocene. The working area of JOB Pertamina Medco E&P (JOB Tomori) is located in onshore (Senoro) and offshore (Toili) areas. New data has been obtained from geological mapping in East Arm Sulawesi followed by laboratory analysis such as sedimentology, petrography, and biostratigraphy analysis which when combined with subsurface data has created an integrated sedimentation dynamic model for a new exploration perspective in this area.

The new perspective is that the Tomori Formation – Matindok Formation were not deposited in the same geological age in onshore. The North Senoro Area has a larger unconformity (N8 to N16) than the South Senoro Area (N12 to N14-N17) caused by uplifting prior to a collision event along the Batui Thrust. Following that event, a Clastic Molasse sediment known as the Kintom Formation was deposited from multiple provenances based on Q-F-L analysis and paleo-current measurements from outcrop. The first provenance came from the Paleo-High in North-East deposited to South-West and another came from an uplifted area in North-West thus creating a seismic attribute event showing a multidirectional submarine fan system in the Senoro Area. Petrography results show two different samples, one with more significant quartz monocrystalline (~67%) than mafic mineral (<10%) interpreted as platonic craton from the Paleo High in North-East, and the other with less quartz monocrystalline (~20%) than mafic mineral (~25%) interpreted from the ESO in North-West.

These unconformities with different rates can possibly act as a compartment in a reservoir. Therefore, multiple provenances when Celebes Molasse was deposited will have an impact in terms of reservoir quality in post-collision play where the related platonic craton source will have better reservoir properties than the source from the uplifted ESO from the North-West direction. Additional analysis will be needed to de-risk this new exploration play based on sandstone provenance before proposing an exploration well location.