Managing director Grant King told investors at a Macquarie Conference in Sydney on Wednesday that Origin had an extensive portfolio of exploration prospects in Australia (the offshore Otway and Bass Basins), Kenya, Vietnam and New Zealand.

"Some of these prospects will be drilled or considered for drilling over the next few years and if successful have the potential to add significantly to the reserve base of the company," King said.

He said prospects already identified in Origin's offshore New Zealand acreage had the potential to contain up to 863 million barrels of oil and about 20Tcf of gas in unrisked mean recoverable reserves.

Origin's Australian, African and Asian acreage together had the potential to contain up to 989MMbbl of oil but only about 4Tcf of gas.

King said that Razorback in offshore Otway licence T/34P (Origin interest 31%) could contain about 295 billion cubic feet of gas, while the Trefoil, White Ibis, Rockhopper and Gentoo fields in T/18P offshore Bass Basin could hold 153Bcf, 36Bcf, 148Bcf and 49Bcf respectively. Silvereye, in T/44P, could contain 317Bcf of gas.

He added the Mbawa prospect in Kenya's offshore Lamu Basin could hold up to 878MMbbl of oil or 2.76Tcf of gas while Swordfish and Flounder in Vietnam's Block 121 (100%), could contain 55MMbbl and 56MMbbl of oil respectively.

In New Zealand, King said Origin had already identified eight significant prospects or leads, plus the Momoho prospect near the commercial Kupe field, that together could hold about 20.6Tcf of gas and 863MMbbl of oil.

Six were located in the Northland Basin with PEP 38618 leads, D1, D2 and D3, having the potential to hold 2.13Tcf, 10.57Tcf and 2.93Tcf of gas respectively while the Tarapunga, Kokako and Greater Korimako South in PEP 38619 could hold 360Bcf, 849Bcf and 894Bcf of gas respectively.

The Caravel prospect, offshore Canterbury licence PEP 38262 (100%), could contain 124MMbbl of oil or 451Bcf of wet gas and 16MMbbl of condensate; while Carrack could contain 639MMbbl of oil or 2.34Tcf of wet gas and 84MMbbl of condensate.

King said Momoho, in the Kupe mining licence PML 38146 (50%), could contain 100Bcf of gas. The jack-up Ensco Rig 107 is scheduled to drill Momoho later this month after it has completed and tested the three Kupe development wells.

King said Origin was also committed to drilling Silvereye, Rockhopper and Razorback.

All three PEP 38619 prospects were matured to drillable status, as were Carrack and Caravel, Gentoo in the Bass Basin, and Mbawa off Kenya.

Origin exploration manager Rob Willink has previously told PetroleumNews.net that Origin hopes to be able to drill at least two of the New Zealand prospects in 2009-10.

He has also said the PEP 38619 leads are targeting Eocene-aged turbidites and that the PEP 38619 prospects are either fault-dependent closures targeting potential Miocene and Eocene-aged reservoirs or Pliocene-aged turbidite plays.