Project Profile
Value: Undisclosed
Location: Brunei Darussalam, Island of Borneo
Reserves: 128 million m3 oil, 35 million m3 of condensate and 345 109 m3 gas
Start-up Year: 1965
This is the country’s oldest offshore field, 13km off Kuala Belait. The Ampa field is in water depths of 10 to 40 metres. The field was discovered in 1963 by well Southwest Ampa-1 (SWA-1).
The field is divided into 3 major hydrocarbon-bearing areas: 1) Main field, 2) Southern area and 3) the 21-area (named after the discovery well Southwest Ampa-21). Frist production began in 1965 from the Main field and reached 9,500 m3/d in the period between 1968 and 1970. In 1973, peak production rates from both the Main field and 21-Area totalled some 20,000 m3/d, and gas began to be supplied to the Liquefied Natural Gas (LNG) plant at Lumut.
To date, 279 wells have been drilled in the field and 161 are currently (1/1/96) producing. Most wells can produce from several intervals and many have dual string completions. The average 1995 production rates were some 8,400 m3/d liquids (6,950 m3/d of oil and 1,460 m3/d of condensate) and 21 million m3/d gas. The ultimate recovery for the field is estimated at 128 million m3 oil (36% recovery), 35 million m3 of condensate (42% recovery) and 345 109 m3 gas (86% recovery).
Oil reserves are evenly distributed between the Main field and 21-Area. The Southern Area contains only gas. Gas reserves consist of non-associated gas and gas contained in gas caps to oil reservoirs.
Geology
The reservoirs are heterogeneous, stratified, fine to very fine grained deltaic sands with varying clay content, separated vertically by shales of great lateral extent. All sands silt-out northeastwards across the field. Typical permeabilities are 100-300 mDarcy (0.1-0.3 m2) at 25% porosity.
There are some 625 reservoir units with STOIIP\'s ranging from 0.002 to 26.7 million m3, between 1,000 and 3,500 metres subsea.
The Southwest Ampa oil is light (40° API, 825 kg/m3) with an initial low viscosity (0.35 cp), hence the mobility ratio is favourable. Initial solution gas/oil ratio (GOR) ranges from 70-2,300 m3/m3.
In the deeper accumulations, most oil reservoirs have extensive gas caps with initially about one-half the hydrocarbon pore volume being gas filled.
Oil recovery factors are likely to vary between 25 and 40% of the total oil (STOIIP) with the higher recoveries for the larger reservoirs, mainly in the 21-Area. An estimated 70% (range 50-80%) of gas initially in place (GIIP) is likely to be recovered.
Most of the oil reserves in Southwest Ampa have been produced, but it will remain a major gas source for many years. The field is the principal contributor for the export of LNG via the Liquefied Natural Gas plant at Lumut.
Operators:
The Brunei Shell Petroleum: Operator with 100% interest
Contractors:
Hyundai Heavy Industries: Amdp-30 - Platform & Pile, Conductor Pipeline : 3 Km, Power Cable : 3 Km
MMCOG: Detailed Design for Ampa-9 HP Compressor Module
McDermott International: Pipeline work for 2017, transportation and installation (T&I) of pipelines and umbilicals in the Fairley and Ampa Fields. McDermott will deploy Derrick Barge 30 (DB 30) for the pipeline work. (June 2016)