Skip to the content

The Woodside-operated Pluto field, discovered in 2005 with the Pluto-1 well, is situated in the North West Shelf of Australia in the Carnarvon basin 40km east of the Jansz field. The target is located below the continental slope in water depths ranging from 0.4 - 1km. Four saillines through the centre of the field are fed into the XWITM algorithm for velocity model optimisation.

XWITM model evolution

The new technique implemented here is based on constructing a temporary high-wavenumber perturbed model for a fixed background model before updating the background model with AWITM. The RWI perturbed models are in the left column and the AWI background models in the right column. This gives the starting point for FWI to begin resolving the target over a kilometer below the diving wave zone.

 

Starting

Starting

4Hz RWI perturbation model

4Hz RWI perturbation model

4Hz AWI model

4Hz AWI model

5Hz RWI perturbation model

5Hz RWI perturbation model

5Hz AWI model

5Hz AWI model

6Hz RWI perturbation model

6Hz RWI perturbation model

6Hz AWI model

6Hz AWI model

8Hz RWI perturbation model

8Hz RWI perturbation model

8Hz AWI model

8Hz AWI model

8Hz FWI model

8Hz FWI model

Model validation: predicted and observed data alignment

Cost function reduction with global minimum convergence leads to predicted data increasing its fit with the field data. The panels show predicted data on the left and the corresponding observed data being matched on the right for a randomly selected shot gather. 

 

Model validation: PSDM before and after XWITM

Pre-stack depth-migrated stacks and gathers are generated to QC the velocity update. Left is before and right is after.

S-Cube Cloud

Run FWI on the Cloud

Discover an unprecedented increase in the resolution of your velocity model.