This is the Attaka field, a super-giant offshore oil field located 12 miles from the shore of East Kalimantan in Indonesia. It was discovered by Unocal in August 1970. Unocal, and later on Chevron, was the operator of the Attaka unit on a 50-50 interest basis with Inpex. Attaka field is considered a super-giant oil field having 1023 MMBOE of recoverable reserves.
Here are the interesting facts about the Attaka unit:
- Two years after its discovery, Attaka field started producing oil in November 1972, making it as the first offshore field in Indonesia.
- It has 10 platforms, 6 of which are remote well head platforms producing oil and gas from 109 wells.
- Five subsea wells were completed in 1981-1984 to produce the oil accumulation in areas out of reach of the existing remote platforms. These are the first subsea completions in Indonesia and in Asia.
- Following the first discovery well, the Attaka Well 1A, seven appraisal wells were drilled to assess to size and potential of the hydrocarbon accumulation.
- The huge Attaka reservoir, formed in the very prolific Kutei basin, is a faulted anticline. It has an areal closure of 8000 acres. Attaka field is one of five super-giant fields discovered in the Kutei basin.
- Its oil reserves are attributed to oil found in 22 separate sands at depth between 2800 feet and 7600 feet.
- Attaka sands have very high permeability. It is as high as 5 Darcy in some wells.
- Attaka field daily oil production was 110,000 BOPD at its peak and gas production was 150 MMSCFPD.
- A significant milestone was reached when cumulative oil production of 600 million barrels was recorded at 6:42 PM in March 7, 2001. Cumulative gas production in that same year was 1.3 trillion SCF.
- Attaka field has more than 50 sands with variable oil reserves. Reservoir sand thickness ranges from 5 to 100 feet. To produce them economically, multiple zone completion method using dual tubing strings and multiple packers was selected. This method allows the engineers the flexibility to select from which of the 2 to 4 perforated zones in each well they would like to produce from.
15 October 2017