Cornea Oil Field

Greater Cornea Fields, Browse Basin, Australia

Octanex holds a 18.75% working interest in the Cornea Joint Venture (Cornea JV) including the Cornea Oil Field located in the Browse Basin, offshore from Western Australia and held via a Retention Lease (WA-54-R).

The Joint Venture’s focus is the Cornea Field, comprised of the Cornea South and Cornea Central oil accumulations which are positioned along the Cornea structural trend and share a common oil water contact, although they have separate gas caps. Three other hydrocarbon accumulations are also contained within the retention lease; Cornea North (Tear) which is a separate gas accumulation at the northern end of the Cornea structural trend and Focus and Sparkle which are two separate oil accumulations to the southeast of the main Cornea structural trend.

The Cornea Field is located at a water depth of ~80-90m approximately 150km offshore Western Australia. It represents a large resource with challenging technical parameters being an elongate and petrophysically complex oil rim reservoir with gas cap. Cornea’s attributes make it particularly sensitive to well construction and execution. Reservoir management and sweep efficiency challenges must be resolved for the field to be commercialised.

The field was discovered in 1997 by Shell Development Australia following which Shells secured tenure over the entirety of the field via two exploration permits with a work programme that included 46 commitment wells and 8 secondary term wells. Shell drilled 10 wells between 1998 and 1999, all on 1995/96 2D seismic data, before exiting the permits in 1999 with 36 undrilled commitment wells.

The Cornea JV was awarded an exploration permit over the field in 2003. The Cornea JV reprocessed ~1,000km2 of 3D seismic over the Cornea structure which generated a marked improvement in sub-surface imaging and enabled a more accurate assessment of potential reservoir sweet spots. In December 2009 the Cornea JV drilled Cornea-3 and established the presence of an oil column (23m) and a free water level in the Cornea Central structure for the first time.