Basin Development, Paleogeographic Evolution and Sandstone Reservoirs Characteristics within the Early-Late Miocene Play, Northern Malay Basin

Summary Northern Malay Basin is located northeast offshore Peninsular Malaysia, in water depths ranging from 50m to 80m. This part of the Malay Basin, which is relatively less explored, comprises three geological terrains: basin centre, west flank and east flank. This paper summarizes the results of the evaluation of the seismic geomorphology and reservoir characteristics of the sand bodies within the stratigraphic units Groups D to J that, facilitated the evaluation of basin development and paleogeographic evolution of this area. From the mid Middle Miocene (Group F) to lower Late Miocene (Group D), the main depocentre which trends NW-SE, was dissected by a series of north-south trending faults acting near the centre-to-western part of the basin and resulted in a bending in the southern part of the depocentre. The basin developed into two connected depocentres towards the end of Group D times – a north-south and a second east-west trending depocentres. The gentle eastern flank of the basin recorded the preservation of many intervals of channelised fluvial reservoir sand-bodies. The steeper western flank recorded many intervals displaying sedimentary lobes and patches, possibly representing some form of alluvial fan deposits.