2D structural modelling and hydrocarbon potentiality of the Sitakund structure, Chittagong Tripura Fold Belt, Bengal Basin, Bangladesh

• Published in: Journal of the Geological Society of India Vol. 85; no. 6; pp. 697 - 705
• Main Authors: Abdullah, Rashed, Yeasmin, Rumana, Mahbubul Ameen, S.M., Khanam, Farida, Bari, Zahidul
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 01-06-2015; Springer Nature B.V
• Subjects: Anticlines; Basins; Belts; Earth and Environmental Science; Earth Sciences; Fault lines; Geology; Hydrocarbons; Hydrogeology; Marine; Mathematical models; Modelling; Petroleum geology; Plate tectonics; Porosity; Sealing; Shale; Shales; Bangladesh; ISW, Bangladesh; Fault-seal analysis; Bangladesh; Shale Gouge Ratio (SGR); 2D structural modelling; Shale Smear Factor (SSF); Shale diapirism
• ISSN: 0016-7622; 0974-6889
• DOI: 10.1007/s12594-015-0266-8

The Sitakund anticline is located within the Chittagong Tripura Fold Belt of the Bengal basin is considered to be the youngest structural feature of the western flank of the Indo-Burman ranges. An attempt has been made to delineate hydrocarbon trap configuration by integrating both surface and sub-surface observations, determining the nature of deformation, predicting the sealing probabilities and relationship between different petroleum elements. 2D structural modelling along the Sitakund anticline suggests that the structure may have a suitable fault-trap setting for hydrocarbon accumulation. Along the footwall block the Bokabil sandstones (with porosity up to 14%) covered by cap rock of Upper Marine Shale (UMS) juxtaposes against the shale-rich Bhuban Formation of the hanging-wall block provides such fault-trap geometry. While relatively high Shale Smear Factor (>75%) and low Shale Gouge Ratio (~ 1.33) indicates that the east dipping major thrust fault may provide sufficient sealing properties. In addition, shale diapirism at the core of the anticline may result intrusion of clay into faults considerably raising the sealing ability along the main thrust.