|Geography||Regional Geological Setting||Structure||Stratigraphy|
|Oil and Gas||Peat and Coal||Other Minerals||References|
Oil seepages have been known in the eastern part of Brunei for many years. 'Earth oil' was collected and used by the local communities for domestic lamps way back in the 19th century and probably long before. Modern oil exploration in Brunei Darussalam began in 1899 when a 198 metre deep hole was drilled at Ayer Bekunchi at the site of an oil seepage near Bandar Seri Begawan (Kampong Kasat). No commercial hydrocarbons were encountered. Nearby oil seepages into coal exploration adits (drifts) on Berambang Island (Figure 1.1) were exploited between 1902 and 1924.
In 1911, a geological survey was made on behalf of the British Borneo Petroleum Syndicate. This company, which also explored the whole of Sabah, subsequently acquired oil prospecting and mining rights over parts of the Belait district. It drilled four wells (Belait-1 to Belait-4) near and on the Belait anticline in the Labi area from 1912 to 1916, but without commercial success (see Belait; exploration history). During this same period, a Singapore consortium, the Shanghai Langkat Company, obtained oil mining rights over a small area at Jerudong and drilled five dry exploration wells during 1913-1917 (see Jerudong; exploration history).
Meanwhile, Shell was active across the border in the Miri area. Oil seepages in northern Sarawak were first reported by C. de Crispigny, resident of the Baram district of the Sarawak government, in the middle of the 19th century. They were brought to the attention of Shell by his successor, Charles Hose (Hose, 1927). Shell investigated the seeps and mapped the area. Subsequent drilling resulted in the discovery of the Miri field in 1910, the first commercial oilfield in Northwest Borneo. Stimulated by this discovery, Shell increased its exploration activities in the adjacent parts of Brunei Darussalam.
In 1913, Shell's affiliate the Anglo Saxon Petroleum Company, which later became the British Malayan Petroleum Company (in 1922), acquired concessions near Tutong. Another Shell company, the Asiatic Petroleum Company Limited, obtained rights in 1922. These rights were later also transferred (1924) to the British Malayan Petroleum Company. Early shallow drilling in the Tutong, Jerudong and Belait districts was not successful. Anglo Saxon obtained the concessions in the Labi hills from the British Borneo Petroleum Syndicate and the company took over ongoing drilling operations. Well Belait-2 was the first well to strike oil, albeit non-commercial, in Brunei Darussalam at a depth of 560 metres (TD). By 1924, Shell had acquired additional acreage in the Belait district. The company embarked on a exploration campaign, using newly introduced geophysical methods (gravity), which led to the discovery of the large Seria field in 1929 (see Seria; exploration history; Harper, 1975; BSP 1989).
Brunei Darussalam saw little exploration efforts during the global economic recession. A seismic party was introduced as early as 1939, when it was a new exploration method. Deep (rotary) drilling became possible at this time and a new drilling campaign started by drilling a deep well at Jerudong in 1939-1940. Operations were halted by World War II and could not be resumed until the early 1950's, with the drilling of deep wells in the Seria-Rasau areas, the Belait anticline (Belait-11 to Belait-14) and Jerudong. Extensive exploration field studies before and after World War II, notably in the 1950's, resulted in the first detailed geological description of North Borneo (Liechti, 1960).
Following the extension of Brunei's boundaries to include the Continental Shelf in June 1954, BSP acquired offshore rights. After a marine seismic survey campaign, the first offshore well was drilled in 1957 from a fixed platform at Ampa Patches (see SW Ampa; exploration history). The well did not find hydrocarbons, and offshore drilling was suspended because of the high drilling costs. The introduction of mobile offshore drilling units (Orient Explorer and Sidewinder) and rapid improvement in marine seismic technology in the late 1950's and early 1960's provided new impetus for offshore exploration. Brunei Shell discovered the Southwest Ampa gas/oil field and the nearby '21 Area' in 1963 and 1966, respectively, and the Champion oil field in 1970. The smaller Fairley fields were discovered about the same time (1969-71) while Magpie was found in 1975. The Iron Duke accumulation was discovered in 1984, although the first Iron Duke well had been drilled in 1961 (see oil&gas fields).
Figures 5.1 and 5.2 summarise the exploration history of Brunei Darussalam. Scherer (1981) gives an interesting account of exploration activities in the adjacent territories of Sarawak and Sabah.
From 1965 to end-1995, over 47,500 kilometres of 2D seismic has been shot in Brunei Darussalam. Since the late 1980's BSP has acquired mainly 3D seismic surveys with more than 8,600 km2 shot to end 1995. From 1913 to 1995 BSP and its predecessors drilled 154 exploration wells; 96 offshore and 58 onshore. From these activities, 12 commercially exploitable oil and gas fields including the major accumulations - Seria, Southwest Ampa and Champion - have been found (Figure 5.3). The oil and gas from the developed fields is transported via pipelines to BSP's Seria oil and Lumut Liquefied Natural Gas (LNG) terminals.
During 1995, BSP's daily production averaged some 27,800 m3 of liquids and 30 million m3 of gas.
Periodically, non-Shell companies have drilled exploration wells in Brunei Darussalam, for example the British Borneo Petroleum Syndicate, Sunray, Elf Aquitaine, Jasra Jackson, Jasra Elf and Fletcher Challenge. Up to 1995 they drilled 14 offshore exploration wells and 15 onshore wells (mainly in the first half of this century) and discovered three offshore hydrocarbon accumulations: Perdana, Juragan and Maharaja Lela. Currently only Maharaja Lela is considered for development.
Figure 5.3 shows the oil and gas accumulations, infrastructure and the current concession areas in Brunei Darussalam.
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