Oloibiri Oilfield was discovered on Sunday 15 January 1956 by Shell Darcy.^[10] It was the first commercial oil discovery in Nigeria; this discovery ended 50 years of unsuccessful oil exploration in the country by various international oil companies and launched Nigeria into the limelight of the Petro-State.^[11]

Following the discovery of oil in commercial quantities in Oloibiri, Shell stepped up exploration in the Niger Delta and by 1958 Shell Darcy had discovered oil in twelve areas in the Niger Delta of which Oloibiri, Afam and Bomu were the most promising.^{[citation needed]}

The discovery well Oloibiri −1 was spudded on 3 August 1955 and drilled vertical to a total depth of 108 feet (3660m).^[12] The well was tested and it flowed at the rate of about 5,000 barrels (790 m³) of oil per day and it was deemed to be a commercial discovery. Some gas was also discovered with the oil. The oil discovery was made in the Tertiary Agbada.^[10]

Between 26 June 1956 and 28 October 1958, 11 appraisal wells were drilled vertical to the appraisal of the extension^[13] of the reservoir to different sections of the field.^{[citation needed]} The first appraisal well was Oloibiri-2, it was spudded on 26 June 1956 and drilled vertically to a total depth of 2932m and it encountered oil in the Agbada Formation.^{[citation needed]} Six of these appraisal wells were a success and encountered oil pay.^[14]

An appraisal well Oloibiri-17 was spudded on 9 June 1967 after 9 years of production and drilled deviated to a measured depth of 12520 feet (3816 mD) but the result was not encouraging.^{[citation needed]} Oloibiri-17 was plugged and abandoned. The field production was on depletion from its peak production and the well was drilled to appraisal another section of the field so as to increase production.^[15]

Another appraisal well Oloibiri-18 was spudded on 21 April 1979 and drilled to a vertical depth of 9616 feet (2931 m) but the result was also discouraging.^{[citation needed]} The field was almost depleted at that time.^{[citation needed]} The main objective of the Oloibiri-18 was to appraise a new section and improve the drainage of the reservoir but the well was dry with shows and so it was plugged and abandoned.^{[15][citation needed]}

Following the successful completion of the appraisal of the field, four development wells were drilled in 1958 (between 17 June 1958 and 27 November 1958) for the development of the field.^{[citation needed]} The four development wells and the six successful appraisal wells were completed as oil production wells.^{[citation needed]}

The discovery well, Oloibiri-1 was completed on 5 June 1956 as a commercial oil production well. Thus, Oloibiri-1 made history as the first truly commercial oil well in Nigeria. This brings the number of completed production wells on field to eleven.^{[16][citation needed]}

The field started oil production between late 1957 and early 1958 and the first oil production from the field came at the rate of 4,928 barrels per day (783.5 m³/d).^{[citation needed]} The field produced at an average rate of 5,100 barrels (810 m³) of oil per day for the first year. The production increased thereafter as more wells were completed and put onto production and reached its peak in 1964.^{[citation needed]} The field was drained from eleven production wells.^{[citation needed]} The oil produced from the field is sour and heavy and has an API of 20.6.^{[citation needed]} The gas produced with the oil was flared off as a result of lack of gas processing and utilisation facility in the country then, so the gas was not considered necessary.^{[citation needed]}

Royal Dutch Shell laid the first crude oil pipeline in the country from the Oloibiri field to Port Harcourt on Bonny River to access export facilities.^{[citation needed]} Nigeria exported its first crude oil in February 1958 from the Oloibiri oil field, initially at the rate of 5,100 barrels per day (810 m³/d).^{[citation needed]} The oil was being pumped from the field via the country's first pipeline, laid by Shell.^{[citation needed]}

The Oloibiri oilfield produced over 20 million barrels (3,200,000 m³) of oil during its 20 years life cycle.^{[citation needed]} Oil production finally stopped in 1978 and the field was abandoned the same year.^[17] The Oloibiri oilfield was abandoned without any improved recovery to drain some of the 21.26 million barrels (3,380,000 m³) of hydrocarbon still left on the field.^{[18][citation needed]}

General references edit

• Chuks Onyems, Nigeria Oilfields Encyclopedia.
• "HISTORY OF THE NIGERIAN PETROLEUM INDUSTRY". Archived from the original on 26 July 2009.
• "Nigeria - History of Oil Exploration. - Free Online Library". www.thefreelibrary.com.