## 2 Geological Setting  
The Australian North-West Shelf (NWS) Browse Basin is a passive continental margin that stretches between the latitudes of 21\({}^{\circ}\) and 13\({}^{\circ}\) S from the SW to the NE. The Browse Basin is located in the southern edge of the Timor Sea, between the Scott Plateau to the west, the offshore Kimberley Block to the north, and the Scott Plateau to the east. It covers an area of over 140,000 km\({}^{2}\), and its sedimentary depth exceeds 15 km (Figure 1). On the NWS, it is one of several lengthy sedimentary basins. The area evolved via six geological periods, from early Carboniferous to Late Jurassic inversion to late Cretaceous inversion. Thermal subsidence occurred during the Permian and Triassic ages. The central Browse Basin is a margin-parallel half-graben system that structurally dips towards the continent [37]. The break-up of Greater India from Western Australia resulted in either a single phase or two phases of rifting, which led to the development of the NWS [38]. A thick succession of passive edge sediment was deposited in the Browse Basin after tectonic activity in the Aptian had halted, burying the old structural relief [39]. Several petroleum systems have been determined, implying that at least three major petroleum systems exist.  
The primary structural patterns in the Browse Basin were likely produced by the final stage of rifting that occurred in the Middle Jurassic-Early Cretaceous (Figure 2). The Plover Formation is made up of a series of stacked fluvio-deltaic and shallow marine sands, shales, and silts, as well as trace amounts of carbonate and volcanic materials during active faulting of the Jurassic extension [40]. As a result, the thickness and lateral continuity of this formation range approximately 200-450 m thick; sandstones are extensively variable throughout the basin. A regional unconformity is marked at the base of the Plover Formation whereas the top of Plover is defined as Late Callovian age uncomformity. A significant volcanic province is present in the Browse Basin throughout the Early to Late Jurassic [41]. Most traps in the area are structural; however, there is potential for chronological traps on the margins of existing structures and alluvial/submarine fans dumped on the hanging wall of significant horsts. The rifting is related to volcanic activity, which might deteriorate reservoir quality and absorb habitation space, inhibiting sandstone deposition [40]. The research area's source rocks were deposited in the broad fluvial-deltaic channels that spanned most of the basin. Prodelta shales, coaly shales, and shallow coals harboring abundant marine organic materials are examples. Applying well data, the Near Top Plover Formation has been examined and is interpreted as an upward increase in acoustic impedance. The structure of the rocks above and below this barrier is thought to be varied, with the possibility of sand on shale, shale on shale, and shale on sand interfaces. As a result, the seismic marker at the Near Top Plover Formation varies spatially [42]. The Near Top Plover Formation is a consequence of the fact that the surface of the Plover Formation is a consequence of the fact that the surface of the Plover Formation is a consequence of the surface of the Plover Formation.  
Figure 1: (**A**) Location of Browse Basin, Australia, on the world map. (**B**) Location of different sub-basins (Poseidon, Crown, Torosa, Brecknock, Calliance, and Caswell) where the rectangular red block represents the Poseidon field that is our study area (modified after [40]). Reprinted with permission from Springer Nature.  
horizon is distinguished by underlying complex faulting. Normal faults resulted in a series of fault ridges and grabens. This makes detecting and delineating the Plover Formation's gas saturated reservoir extremely challenging for the Browse Basin [43].