Updated:8 January 2007

Australian petroleum exploration and development activity report

1 October to 31 December 2005

To view the full report, including tables and figures you can download the Petroleum Industry Statistics Report for 4^th Quarter 2005 in PDF format [PDF 505KB].

Highlights

There were 6 petroleum discoveries reported in the quarter.
Offshore, there were two gas discoveries made. Gas discoveries were at Highgrove and Kultarr in the Carnarvon Basin.
Onshore, three gas and one oil discoveries were made. All were in the Cooper Basin with an oil discovery at Padulla and gas discoveries at Greenmount, Rossco and Theta.
During 2005 offshore, exploration drilling accounted for 68 wells, which is the largest drilling activity since 1998. It is 26 wells more than that achieved in 2004 and 10 more than that in 2003.
Onshore Exploration drilling in 2005 accounted for 77 wells drilled, which is four less than the 81 wells drilled in 2004. This current level of drilling is still significantly more than what was achieved in 2003 where 39 wells were drilled.
Overall seismic activity in 2005 has remained similar to that achieved in 2004. Onshore seismic for both 2D and 3D has remained constant over the two periods. The biggest change was offshore where 2D seismic activity decreased 4923 km, and 3D increased by 13803 km² compared to 2004.

[back to top]

Drilling activity

Exploration drilling for the December quarter 2005, totalled 41 wells, which is the same as that drilled in the previous quarter and one more than the same period in 2004.

Offshore exploration wells drilled during the December quarter 2005 totalled 14 which is three less than in the September quarter 2005 and two less than in the December quarter 2004. Seven of these wells were drilled in the Carnarvon Basin, four in the Gippsland Basin, one each in the Browse, Bonaparte and Perth Basins.

Onshore exploration wells in the December quarter 2005 totalled 27 which is three more than the previous quarter and three more than the December quarter 2004. Thirteen of these wells were drilled in the Cooper/Eromanga Basin, five in the Perth Basin, three in the Otway Basin and one each in the Bowen and Gippsland Basins.

Development drilling activity for the December quarter 2005 of 22 wells is one more than the September quarter 2005 and one less than the December quarter 2004.

Offshore, the number of development wells drilled during the December quarter 2005 was seven. This is two less than the previous quarter and three less than the same quarter last year. Five of these wells were drilled in the Carnarvon Basin and two in the Gippsland Basin.

Onshore, there were 15 development wells drilled in the December quarter 2005. This is three more than the previous quarter and two more than the same quarter last year. All of these wells were drilled in the Cooper/Eromanga Basin.

[back to top]

Seismic survey activity

Offshore, there was a significant increase in seismic activity during the December quarter 2005 compared to the previous quarter, reflecting similar increases in previous years. The total 2D seismic of 9182 km was 8397 km more than the previous quarter and 2358 km less than the December quarter 2004. 3D seismic activity covered 4707 km², which was 2866 km², more than the previous quarter.

Onshore, a total of 1128 km of 2D seismic was acquired during the December quarter 2005, being 952 km more than the previous quarter and 728 km more than December quarter 2004. 3D seismic surveys covered 194 km², which is 119 km² less than the previous quarter and 219 km² less than the December quarter 2004.

[back to top]

Rig activity

The number of active rigs at the end of December 2005 was 21, just one more than at the end of September 2005 (20) and three more than at the end of December 2004 (18). The number of active rigs during the quarter ranged from 21 to 23 during July increasing to twenty in August and September 2005.

Offshore, the number of available rigs during the December quarter 2005 has varied between eleven and nine This is a small decrease over the average of eleven per month. The percentage of rigs active during the quarter ranged for 80 to 89 percent, reflecting the high demand for offshore rigs. Active rigs were drilling in the Bonaparte, Browse, Carnarvon, Perth, and Gippsland Basins.

Onshore, the number of active rigs during the quarter ended December 2005 varied between 13 and 14, which is slightly more than the previous quarter where it varied between 10 and 12 active rigs. The percentage of rigs active for the December 2005 continued to increase to 70 percent, reflecting a high demand for rigs. Active rigs were drilling in the Perth, Cooper/Eromanga, Otway, Gippsland, Bowen, Surat and Clarence/Moreton Basins.

[back to top]

Success rates

The success rates are based on the number of petroleum discoveries and new-field wildcat wells drilled in Australia onshore and offshore from 1993 to 2005. No assumptions have been made about whether a ‘discovery’ has proved or will prove to be commercial. Geoscience Australia defines a discovery as a well from which a measurable amount of oil or gas has been recovered and also includes those discoveries inferred from well logs.