Photo: Keraudren seismic survey area; Source: Santos

Santos’ Keraudren seismic survey ‘very encouraging’

Oil company Santos has completed fast track interpretation of the data acquired during the Keraudren 3D seismic survey offshore Australia, resulting in a high-quality data set.

The Keraudren 3D survey covered parts of WA-437-P and WA-438-P in which Santos holds an 80 and 70 per cent stake, respectively. Its partner in the licences is Carnarvon which holds the remaining interests.

The purpose of the 3D survey was to assist with the advancement of the Dorado oil and gas field development and to prepare for the potential drilling of several high-graded exploration targets.

More importantly, the Keraudren 3D survey has been designed to improve the data quality over the Caley, Crespin, Baxter, and Milne intervals. These intervals contain significant quantities of oil and gas as proven in the Dorado-1 well.

The survey, which started in late May 2019, covered some 3,090 square kilometres. At the time, the timing of the fast track data delivery was supposed to assist with field development planning and to support a final investment decision target for Dorado expected in late 2020.

Currently, the FID date was pushed back to 2021, subject to market conditions at the relevant time.

As for Keraudren, Carnarvon said on Wednesday that it delivered a very high-quality fast track data set over the Dorado and Roc fields and the surrounding area based.

According to the company, a higher quality data set is due to be received before the end of the 2020 calendar year.

The Keraudren 3D seismic data was acquired in 2019 using world-first “source over streamer” technology. The resultant 3D seismic data volume has improved the visibility of the key geological intervals associated within the hydrocarbon zones of the Dorado and Roc fields and by extension within these intervals in the surrounding area.

The seismic mapping has also confirmed the structural integrity of the Apus prospect – previously mapped on the Bilby 2D data – and the Pavo prospect.

Carnarvon recently applied semi-automated seismic interpretation software to the new Keraudren 3D data. The results provide a clearer view of the Dorado field, the surrounding prospects, and the basinal architecture covered by the new data.

Carnarvon’s managing director and CEO Adrian Cook said: “We know that we are working in a prolific new hydrocarbon basin on the North West Shelf, most particularly following the successful Dorado and Roc discoveries and appraisal results.

We are currently working with the new Keraudren 3D seismic data to determine follow up exploration potential in the area and to support the Dorado field development work.

Whilst still very early in the mapping process, exploration wise, we are very encouraged by the observations from our team’s work to date”.

Two things are worth adding. Namely, Santos started the competitive process for the supply of the Dorado FPSO last month, and a shortlist of contractors will be invited to tender for the wellhead platform shortly.

Dorado field illustration; Source: Santos
Dorado field illustration; Source: Santos

Also, NOPSEMA approved Santos’ Keraudren Extension 3D seismic survey. It will cover a portion of exploration permit areas WA-435-P, WA-436-P, WA-437-P, and WA-438-P, and surrounding waters in the Bedout Sub-basin.

The survey data will assist with the exploration permit retention strategy and the potential location of future drilling of exploration and development wells.