COMPUTER MODELLING OF THE OXFORDIAN DEPOSITIONAL SYSTEMS IN THE KENDREW TROUGH, DAMPIER SUB-BASIN

Abstract

A 3D depositional modelling program, SEDSIM, was used to model the various depositional systems operating in the Kendrew Trough, Dampier Sub-basin during a two million year period of the Oxfordian. The simulation covers an area of 40 km by 100 km, from the Goodwyn Field in the southwest to the Lambert Field in the northeast, covering the Rankin Trend, Kendrew Trough, Madeleine Trend and part of the Lewis Trough. The simulation started from the Jurassic main unconformity (156.7 Ma) forward to 154.7 Ma using a spatial resolution of 1 km and a time step of 5 ka.

The 3D model from the simulation quantitatively mimics the interaction of the palaeogeographic setting, sediment supply, sea level fluctuations, tectonic movement and palaeo-oceanographic setting in three dimensions, to simulate the spatial and temporal distribution of sedimentary facies. The model identified five Oxfordian leads within the Kendrew Trough, including two major slope and basin-floor fan systems, a shelfal-shoreface system, a deltaic system, and a submarine channel system.

The study has shown that 3D depositional models produced by SEDSIM are not only able to depict the spatial and temporal distribution of depositional systems on a basin scale, but are also capable of making useful contributions to the understanding of play fairway and lead development.