Barrow Island Sparse 3D Seismic Services

The key objective of the Gorgon CO2 Sparse 3D Seismic Project is to acquire and process seismic data on Barrow Island (BWI) to provide time - lapse images of the sub surface area expected to contain injected CO2 gas. This data will confirm if the CO2 is behaving consistent with expectations during the early phase of injection and will help future monitor surveys.

Contractor is required to provide technical support, resources and equipment for a time - lapse seismic program. The following is an estimated scope of work and subject to change in tender documents.

Contractor services to include:

* Acquire a baseline seismic survey.
*Acquire two to five (2-5) repeat seismic surveys depending on the results of the earlier surveys.
* Supply a new 2000-3000 channel cable - less seismic acquisition system and a new or as new articulated 30,000kg (66,000lb) Vibroseis vehicle suitable for off - road terrain with limited access.

1 Vibroseis shall also be available for vertical seismic profiles as requested by Company.
2 The equipment will need to remain on BWI for the duration of the monitoring program (due to quarantine requirements).

* Accurate stakeout and survey of vibroseis points (VP) and receiver locations using ‘real time’ kinematic (RTK) GPS surveying method.

Contractor’s personnel will reside on BWI for the duration of each survey.

The nominal survey comprises of:

* Up to Eighteen (18) source lines covering approximately 85 km, of which about 55km is off - road (3m wide tracks). Total number of VPs is about 28,000, assuming a 3.125m VP interval.
* Approximately 30 parallel receiver lines covering a total length of 100 km.

The estimated total number of receiver locations is about 12,000 assuming a 25m receiver spacing and three sub - parallel receiver lines for each receiver line. BWI is a Class ‘A’ nature reserve, and as such there are a number of restrictions on activities performed on the Island. These restrictions have significant implications for designing and acquiring seismic surveys.

Strict quarantine procedures ensure that absolutely no soil, flora or fauna is brought onto BWI. Seismic source and recording equipment should be new or as new to help meet quarantine requirements. Land disturbance from vehicles or personnel must adhere to land allocation limits determined by Company.