Identification of Shallow Pay Zones in the Tantawan area, Gulf of Thailand

Abstract

The objective of this study was to evaluate the potential shallow pays in the Tantawan area and recommend an evaluation program based on seismic amplitude distributions and risk identification. Known shallow pays were characterised in order to find potential new pays located above the Middle Miocene Unconformity (MMU). Well log analysis, mud log interpretation and seismic amplitude studies were used to evaluate these pays. Seismic time slices were studied to identify the distribution of seismic amplitudes and depositional environments together with amplitude attribute studies.  Based on these observations assumptions of potential new pays were created based on: 1) reservoirs are fluvial sands, 2) normal faults are main traps and migration pathways, and 3) a model pay sand is a gas sand with a high amplitude response. According to these three assumptions the possibility of potential new pays can be divided from low to high confidence, which is POSSIBLE NEW PAY, MOST LIKELY NEW PAY and PROBABLE NEW PAY. The best four locations were recommended for further evaluation based on possibility and size of amplitude anomalies.