Publications

Physical models of three dimensional geological structures have been built in order to understand seismic ,wave propagation through their different layering and to provide the seismic representation of geological structures. Models must be built to accurately represent the geological structure while ensuring that the recorded seismic data appears to have the same character and frequency content as the field data. Once a model is built, it is placed in a water tank to simulate offshore conditions or left in dry conditions to simulate land recording. Ultrasonic transducers are then run across them to record 2-D or 3-D data. The seismic records may then be processed as if they were field data to produce conventional 2-D or 3-D profiles of seismic data.This paper describes the methodology of building physical models to simulate two and three dimensional geology while retaining the seismic character of data. It then discusses the seismic acquisition of data over two models, one representing the offshore Perth Basin and another representing the Oliver field discovery, Timor Sea.The Perth Basin case history shows how a model was used to simulate and understand the reason for poor seismic transmission conditions caused by shallow carbonates, while the Timor Sea case history shows how 2-D and 3-D data can be used to define the presence of a potential sealing fault.Both case histories show how seismic recording can be optimised prior to performing field work and suggest methods to resolve the different seismic problems. In addition, the Timor Sea (Oliver) case history shows how an erroneous interpretation can result from the presence of faults which are not real but appear to be present in the data and how an offshore 3-D survey method can be adopted which will remove the erroneous image of such a fictitious fault.