Carnarvon was awarded the previously developed Buffalo field in May 2016, as part of successfully bidding on the WA-523-P permit.

The field was originally discovered in 1996 by BHP and subsequently developed using four wells drilled from a small, unmanned wellhead platform installed in 25 metres water depth, tied back to an FPSO.

Production commenced in December 1999 at production rates up to approximately 50,000 stb/d and terminated in November 2004 after the production of 20.5 MMstb of highly-undersaturated, light oil (53°API) from the Jurassic-age Elang Formation.

In 2016 when Carnarvon commenced the project, the Company initially focussed its technical work on reprocessing of the 3D seismic dataset using state-of-the-art full waveform inversion (FWI) technology.

This supported the interpretation of a significant attic oil accumulation remaining after the original development, based on sub-optimal positioning of early wells using lower quality processed seismic data back in the day.

Significant milestones and developments

Reservoir modelling has been conducted using the latest structural interpretation and available well data, including an extensive history-matching effort to calibrate model/well performance to production rates and water-cut development (governed by strong aquifer drive) observed during the original production period.

Based on this work, independently audited volumetric estimates of contingent resources in the Buffalo oil field are 31.1 million barrels (2C) with low estimates of 15.3 million barrels (1C) and high estimates of 47.8 million barrels (3C).

In December 2020, Carnarvon announced a binding agreement with Advance Energy Plc, an AIM listed international upstream oil & gas company.

The deal is structured so Advance will acquire up to a 50% interest in the Buffalo project at estimated cost of US$20m.

Carnarvon is progressing with its plans to drill the Buffalo-10 well, targeting 2H 2021.

Carnarvon appointed Petrofac as drilling management services contractor.