INDONESIA - South Sumatra.

Several firms operate in South Sumatra, mainly an oil province, including Stanvac, Pan Pacific's Enim Oil, Husky Oil of Canada, and Golden Spike of Bermuda. Their fields are small.

Stanvac has several fields found since the early 1970s, with hydrocarbons reservoired in clastic and carbonate rocks. Stanvac has oilfields in Central Sumatra, which are small as well.

Corridor PSC & Asamera Venture: Asamera Oil Indonesia (AOI), a unit of ConocoPhillips' Gulf Indonesia (which the US major got from its 2001/02 acquisition of Gulf Canada Resources), has oil and gas fields in Asamera region in South Sumatra. Some of these fields are old (like Kluang, found in 1913). In its Corridor PSC which was extended for 20 years in 1989, AOI produces oil from fields including Bentayan and gas from several fields including the large Gelam gas structure which extends north to a block held by Saga Petroleum of Norway (50%) and Pertamina (50%). Gelam has been developed jointly with Saga. This and other Corridor fields, including the Dayung giant, Suban and the 34% CO2-Sumpal field, went on stream in late 1997, and full production began in late 1998. With a 540 km Corridor Gas Pipeline from Grissik to the north completed in late 1998, the fields supply 300 MCF/d to CPI's EOR system at Duri, and 40 MCF/d to other users in North Sumatra.

In the Corridor PSC, AOI holds 54% and is the operator, with a unit of Talisman Energy of Canada holding 36% and Pertamina 10%. A revised 20-year PSA for Corridor was signed with Pertamina in 1996. AOI pledged to invest $65m over nine years on another phase of exploration and booked 670 BCF of net gas, after deducting its CO2 content which is stripped away on extraction, and 3.6m barrels of net liquids in reserves. Future gas developments was to carry a revised 65/35 production split in favour of Jakarta, instead of the standard 70/30 split. Gulf Indonesia's Corridor JV is also known as (Grissik - see background in Vol. 56, No. 10).

Suban, found in January 1999 and confirmed in November 2000 as a giant gas field at a depth of 2,931 m in the Corridor block, has proven reserves exceeding 4 TCF. Gulf has found more than 3 TCF of gas in place in this and other South Sumatra blocks. Suban began gas production in late March 2003 with supplies sent to CPI's Duri. Under a long-term deal between AOI and CPI, Suban supplies to Duri average 120 MCF/d.

Under a 20-year gas sales agreement signed by Pertamina and Petronas, Malaysia imports 300 MCF/d from Suban, Santos' Bentu PSC, and Jambi-Megang field (75% Pertamina & 25% Repsol-YPF) in South Sumatra, with first gas deliveries begun in 2005, when the pipeline to that market came on stream. AOI sells 73% of the 2.19 TCF total gas to Malaysia, i.e., 219 MCF/d. Other markets for these fields are the islands of Batam, Singapore and Java.

Asamera South Jambi (ASJ), another Gulf Indonesia unit, operates the nearby South Jambi B PSC block. There it found in February 1996 an important gas field at Tungkal, 13 km north-west of Dayung and near the gas pipeline to North Sumatra. The gas has 60% CO2 content. Production of net gas began in early 1998 and is supplied to the gas pipeline to North Sumatra which passes through Jambi province. Asamera holds 45%, with 30% held by Total and 25% by Pertamina. ASJ has made several gas discoveries on the block since then.

Gas volumes from the Corridor and South Jambi B blocks, together with gas produced from the Jabung block by Santa Fe (see below), are supplied to CPI's Duri field. Supplies to Duri rose to 480 MCF/d in mid-2003 under a 20-year agreement for a total of 1.1 TCF signed in 2000. Sales within Sumatra reached 530 MCF/d in mid-2003 from the three blocks. Sales to CPI have begun to fall with the fields declining. The pipeline is owned by state controlled PGN.

In the South Jambi B block, ASJ has developed the Mengoepeh field, whose proven reserves was put at 19 BCF of gas and 6m barrels of oil and which is about 35 km to the north-east of a gas pipeline. It has developed the SE Mengoepeh gas field, about 26 km from the pipeline, and the Teluk Rendah gas/condensate field. The latter's gas has a very low CO2 content of 3% and is near the low-CO2 fields Hari and Geger in the same block. The gas from these fields together with reserves in the southern part of the South Jambi B block are bound for Singapore.

In North Sumatra, Asamera operates Block A with a 50% interest in partnership with Aceh Gas & Oil Co. of Japan (50%). There, it found a major field. Its first well, Langsa-1, in 1992 tested 36 MCF/d consisting of 81% CO2 and only 19% hydrocarbons. In later years, it found Alur Siwah, Alur Rambong and Julu Rayeu, with 585 BCF of net gas reserves. On stream in 1999, these are producing about 200 MCF/d of raw gas and supply 120 MCF/d of processed gas to ExxonMobil's Arun field, 45 km away. From there the gas is pumped through ExxonMobil's system to reach the Arun LNG complex. Supplies to the Arun complex and a fertiliser plant in Aceh reached 476 MCF/d in 2006.