Tiaka–Tiara Fault Bend Fold Structures and Its Implication to Hydrocarbon Entrapment Within Eastern Arm of Sulawesi, Indonesia

Abstract

The Tiaka-Tiara Fault Bend Fold Structures geologically is located in a tectonically complex area of Banggai Basin at the eastern arm of Sulawesi, formed by a collision process between the Banggai Sula microcontinent and East Sulawesi ophiolite belt. The Banggai Sula micro continent has been interpreted as a fragment of the major Australia- New Guinea Continental plate, which drifted westerly directed by South Sula-Sorong Fault from the east. The objective of the study is to have a better understanding of the structural geology and fractured reservoir characterization as the impact of fault bend fold structure development. The contractional deformation style has been observed from seismic and structural interpretation and reconstruction. Regional tectonics evolution in the eastern Sulawesi was initiated by drifting of Banggai Sula micro-continent westward through the South Sula-Sorong Fault then collided with the eastern arm of Sulawesi during Late Miocene to Pliocene, resulted in a foreland thrust fold belt structures of Tiaka-Tiara. This complex tectonics system of the Banggai Basin has resulted in a major SW-NE with a series of SSE-NNW oblique minor fault bend fold structural trend which indicates the potential of fractured carbonate reservoirs. The methods used in this study included 2D seismic interpretation, well correlation, structure map generation, and palinspatic reconstruction using balancing cross-section technique. The Minahaki and Tomori Miocene fractured carbonate reservoirs are the main objectives in the Tiaka Fault bend fold structure in Banggai Basin. Significant hydrocarbon production from both fractured carbonate reservoirs has proved the importance of Fault Bend Fold structure. The high fractured density is located along the hinge of the Tiaka-Tiara structural closure which is strongly controlled by Fault Bend Fold geometry. This study concluded that Fault Bend Fold Structure in the Study area is a structural trap characterized by NE-SW low angle detached in basement and involved sequence of Miocene carbonate. Compressional deformation during Neogene time is main controlled of Hydrocarbon entrapment and accumulation in fracture carbonate reservoir of Fault Bend Fold Structure. Syn-drift deposition during Paleogene contributed to control hydrocarbon generation from source rock of marine carbonaceous shale within Lower Miocene Tomori Formation.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015