Abstract
The Wichianburi Sub-basin is currently the only productive area in the southern part of the Phetchabun Basin, central Thailand. It is structurally dominated by NNW-SSE to NNE-SSW trending normal faults as a result of multistage rifting since the Late Oligocene. Half-graben and full-graben basin geometries can be observed from 2D regional seismic sections. In this study, structural restoration techniques were applied to validate the structural interpretation of the original hardcopy of the 2D seismic sections. Stratigraphic information is compiled from published papers and well reports. Our results revealed that most of the deformation was concentrated during the Late Oligocene. Main depocenters for the syn-rift sediments focused in the basin center along the west-dipping normal faults. These faults cut the prerift section and their orientations were possibly controlled by the Permo-Triassic fabrics that underlie the Phetchabun Basin. By measuring the length of the profiles before and after faulting, the restorations show that the extensions of the Wichianburi Subbasin decrease from 12.30% during the main rift phase (Late Oligocene to Early Miocene) to 2.53% during the second phase of rifting. Rifting only focused in the basin center with the development of NNW-SSE to N-S trending intrarift faults. Since the Middle Miocene, the Wichianburi Subbasin has developed under the tectonic phase of post-rift subsidence with interruption by intrusive activities.
Highlights
The Phetchabun Basin is a major onshore Cenozoic basin that lies in central Thailand with approximately 120 km long and around 30 km wide (Figure 1)
It is the only hydrocarbon-bearing sub-basin that produces oil from both fractured volcanic rocks and sandstone reservoirs within tilted fault blocks (Barr and Cooper, 2013). This sub-basin is structurally dominated by the N-S to NNE-SSW trending normal faults as a result of multistage rifting since the Late Oligocene (Pongwapee et al, 2019a)
The results from restorations show that the extension in the E-W direction of the Wichianburi Sub-basin increases toward the north ranging from 8.37% to 12.30%
Summary
The Phetchabun Basin is a major onshore Cenozoic basin that lies in central Thailand with approximately 120 km long and around 30 km wide (Figure 1). According to regional 2D seismic interpretation, five narrow subbasins with half- and full-graben geometries form the Phetchabun Basin (Remus et al, 1993). The Wichianburi Sub-basin is in the southern part of the Phetchabun Basin. It is the only hydrocarbon-bearing sub-basin that produces oil from both fractured volcanic rocks and sandstone reservoirs within tilted fault blocks (Barr and Cooper, 2013). This sub-basin is structurally dominated by the N-S to NNE-SSW trending normal faults as a result of multistage rifting since the Late Oligocene (Pongwapee et al, 2019a)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
