Seismic Data Inversion Analysis Increases Potential of Lion Prospect

Gulf Energy Pty Limited (Gulf Energy) recently commissioned a leading expert in seismic data inversion to analyse the data from two key seismic lines across the Lion Prospect in the Bamaga Basin. Lion is the first prospect Gulf Energy proposes to drill in Q/23P.

Seismic data inversion can indicate the properties of the rock the reflected seismic signal travels through and, if the rock is porous, the nature of the fluids in the rock. The analysis of the seismic data inversion on two cross lines over the crest of Lion Prospect show a marked decrease in P-Impedance with the edges of the P-Impedance ‘low’ approximately coincident with the mapped spill point of the Lion Prospect closure (refer to figure below). Based on industry experience, a P-Impedance decrease could be indicative of porous reservoir rock containing hydrocarbons (gas and/or petroleum liquids). This is very positive for Lion’s prospectivity.

How Does Seismic Data Inversion Help Petroleum Exploration?

Seismic inversion is essentially a very simple procedure. In a seismic inversion the original reflectivity data, as typically recorded routinely, is converted from an interface property (i.e., a reflection) to a rock property known as impedance, which itself is the multiplication of sonic velocity and bulk density. In a conventional seismic reflectivity section, the strong amplitudes are associated with the boundaries between geological formations, such as the top reservoir. This type of data is most suited to structural interpretation. In an inverted dataset the amplitudes are now describing the internal rock properties, such as lithology type, porosity or the fluid type in the rocks (brine or hydrocarbons). Inverted data is ideal for stratigraphic interpretation and reservoir characterization.