Gulf and Southern Highlands Provinces, 85 kilometres south-east of the Kutubu Oil Project
Petroleum Development Licence-3 (PDL-3) encompassing the central part of the SE Gobe field, and Petroleum Development Licence-4 (PDL-4) encompassing the Gobe Main field, the south-eastern and north-western parts of the SE Gobe field and the Saunders field.
Oil Search owns a 36.36% interest in PDL-3 and a 10.0% interest in PDL-4, giving it a 10.0% interest in the Gobe Main field and a 25.55% interest in the SE Gobe Field.
PDL-3: Southern Highlands Petroleum Ltd (40.15%), Santos (held through Barracuda Ltd) (15.92%), Cue PNG Oil Co Ltd (5.57%), Petroleum Resources (Gobe) Ltd (2.0%). PDL-4: Merlin Petroleum Company (73.48%), ExxonMobil, held through Ampolex (Highlands) Ltd (14.52%), Petroleum Resources (Gobe) Ltd (2.0%)
Oil Search Limited operates the Gobe Main and SE Gobe fields and is operator of PDL-4. Santos operates PDL-3
Gobe Main: 30.6 million barrels SE Gobe: 44.6 million barrels
Gobe Main: 3.2 million barrels SE Gobe: 4.2 million barrels
The Gobe Oil Project comprises two producing oil fields, namely the South East (SE) Gobe oil field and the Gobe Main oil field. SE Gobe was discovered in early 1991. The SE Gobe discovery was significant because for the first time commercial quantities of oil in the Iagifu sandstone were found. Prior to this, the majority of oil had been discovered in the Toro sandstone. The Gobe Main field was discovered in December 1993 and is located 5 kilometres to the north west of the SE Gobe field. Oil reserves in Gobe Main are also contained in the Iagifu sandstone. In December 2001, the Saunders field was discovered in PDL-4.
The Gobe Main field is wholly located within Petroleum Development Licence 4 (PDL-4), while SE Gobe straddles the boundary of PDL-4 and adjoining PDL-3. Originally, 55% of SE Gobe oil reserves were attributed to PDL-4 and the balance to PDL-3. A re-determination, effective from June 2001, revised the oil split to 59% in PDL-3 and 41% in PDL-4.
Oil is exported via an 8 kilometre pipeline which joins the Gobe Processing Facility to the Kutubu Export Pipeline and marine loading terminal in the Gulf of Papua. The Gobe Project pays a tariff to the PDL-2 and PL-2 participants for the use of the export pipeline and infrastructure. The construction of infrastructure and production facilities for the Gobe Oil Project was completed in early 1998 and the first crude oil flowed from the Gobe Main field in March 1998 and from the SE Gobe field in April 1998.
Production peaked in December 1998 at 18,500 bopd from SE Gobe and at 20,000 bopd from Gobe Main in September 1999. In early 2005, the SE Gobe 11 well discovered an oil column in an undrained area of the SE Gobe field, located between Saunders and SE Gobe. An appraisal/development programme took place during 2006 to exploit this area. Both fields are now in their decline phase, but active well management and facility optimisation is ongoing, to mitigate the fields' natural decline rates.
As at 31 December 2009, the Gobe project had produced a total of 67.8 million barrels and the gross proved plus probable ultimate recovery was estimated at 30.6 million barrels and 44.6 million barrels for Gobe Main and SE Gobe fields respectively, with 3.2 and 4.2 million barrels respectively remaining. The reserves are contained within generally high permeability oil rims in the lower and upper Iagifu sandstones. As at 31 December 2009, Oil Search’s share of remaining recoverable 2P reserves in the Gobe Project was 1.4 million barrels.
The Gobe project crude oil is a light, sweet 45 degree API oil and is sold as part of the “Kutubu Blend” together with Moran and Kutubu crudes.
Oil Search’s share of production from the Gobe fields during the first quarter of 2010 was 0.08 mmbbls, down 20% compared to the previous quarter.
The gross average production rate of 1,733 bopd for Gobe Main was 4% lower than the fourth quarter of 2009 due to natural field decline. Gross average rates at SE Gobe declined by 25% to 2,784 bopd largely as a result of a five day scheduled shutdown for routine inspection and maintenance, including compressor servicing. In addition, the SEG 3 compressor was offline during January for engine repairs and this impacted production from some of the high gas-oil-ratio wells. All compressors have now been returned to service.
A number of well work and workover opportunities are currently being assessed at SE Gobe which, if implemented, are expected to lead to improved production rates.