Blacktip Gas Field, Timor Sea, Australia


Blacktip gas field is located 110km off the northern coast of Australia in the Timor Sea's Bonaparte Basin. The water depth of the region is 50m. The field is 100% owned and operated by Eni.

First production from the field was achieved in September 2009. Blacktip is the first project to have been developed to supply gas for the domestic market. Gas produced from the field is supplied to the Northern Territory-based utility provider Power Water Corporation (PWC) under a 25-year agreement. The field provides gas to generate electricity for the Northern Territory locations.

Development of the field helped in increasing the energy security in the region. It has also helped in securing gas supply for long-term industrial and economic development.

Discovery, geology and reserves of the Blacktip gas field

Blacktip was discovered in 2001 by the Blacktip-1 well. It was appraised by one appraisal well - Blacktip-2.

The main field reservoir of Blacktip is a four-way dip closure made of stacked gas-bearing sandstones. The sandstones are of the Lower Triassic Mt Goodwin formation and Permian - Upper Carboniferous Keyling and Treachery formations.

Recoverable reserves of the field are estimated at 150 million barrels of oil equivalent.

Development of wells and facilities at Eni's gas field

The Blacktip gas field's development commenced in July 2006. The field is produced through two development wells - Blacktip-P1 and Blacktip-P2. The wells are tied back to the 2,800t unmanned Blacktip wellhead production platform.

The platform consists of a four-legged jacket weighing 1,300t and topsides weighing 585t. It is secured onto the seabed through 800t piles. The platform includes a chemical injection system, fuel gas system, power generation equipment and telecommunications.

The gas produced by the Blacktip platform is exported to an onshore gas processing facility at Wadeye through a 108km long, 18in diameter offshore export pipeline.

Processing systems installed at the Timor Sea-based Blacktip field

"Recoverable reserves of the field are estimated at 150 million barrels of oil equivalent."

Produced gas undergoes initial processing at the Blacktip platform to remove condensate and water. It is then processed at the onshore processing facility before being supplied to PWC.

The Wadeye gas processing facility has a capacity of 1.3 billion cubic metres per year. It includes facilities for gas separation, dehydration, compression, condensate storage and produced water treatment.

Condensate produced at the Blacktip field is stabilised and stored at the onshore processing facility. It is transferred onto marine tankers periodically through a condensate export system located seven kilometres offshore for transportation and exportation to markets. The condensate export system includes an export pipeline and a tanker mooring and offloading system.

Contracts awarded for the gas field project in the Bonaparte Basin

WorleyParsons carried out the front-end engineering design of the wellhead platform, onshore gas plant and the export pipeline. EcOz-VDM was responsible for the environmental impact assessment study of the onshore gas plant.

"Gas produced from the field is supplied to the Northern Territory-based utility provider Power Water Corporation (PWC) under a 25-year agreement."

Saipem won the Engineering, Procurement, Installation and Construction (EPIC) contract for the Blacktip platform and export pipeline. The company used its Castro Otto pipelay barge for the installation activities.

AusGroup was awarded a $22m sub-contract by Saipem for the construction of the wellhead platform, including the jacket, topside modules and piles. It also won a $14m contract for constructing the storage tanks of the onshore gas plant. The civil works contract for the onshore gas processing plant was won by McMahons Darwin.

Monadelphous won a $150m contract to carry out structural, mechanical, piping, electrical and instrumentation works for the onshore processing facility. BondStrong was subcontracted by Monadelphous to carry out pipe installation works.

All the cables required for the Blacktip platform were provided by Cables International. ICON Engineering was contracted to install and commission the platform's crane built by Italy-based Italgru.

Process Group supplied a gas treatment and water treatment package for the processing facility. It subcontracted Dynapumps to supply four pumps. CETCO Oilfield Services supplied a water treatment package for the onshore plant. Other contractors included Petroleum and Mining Engineering, TCG Industries, RANms and Schlumberger.