Suleiman Muhammad Odapu
26 July 2008
The recent move by some senators to revive oil and gas exploration in the Benue Trough and Chad Basin has once again brought to limelight the need to revisit the quest for a viable oil exploration in the two areas. The need is not only to diverse oil exploration and increase input but to find replenishment for the dwindling reserves in the troubled Niger Delta region.
But the big question begging for an answer is why the lack of political will to drill deep in the North? The first move began shortly after the first oil exploration in the Niger Delta and since then, the feasibility studies have been unsuccessful. Many saw the intermittent suspension of the exploration to political factors.
Senator Salisu Musa-Matori, one of the leading campaigners for the new move to revisit the exploration, attributed it to inability of the government to facilitate proper exploration in Benue Trough and Chad Basin and lack of political will to execute the project to its logical conclusion.
"In May, 2001, when I was in the Senate, I raised a motion that brought the new attention of the Senate, the fact of the sudden stoppage of oil exploration in the Benue Trough and Chad Basin. I maintained at that time that though, I am neither an oil engineer nor a crude oil expert, but the stoppage was premature and lacking in both scientific and historic basis," Matori told Weekly Trust.
How it started
Weekly Trust investigations revealed that when the decision was taken to explore the possibility of finding hydrocarbon deposits in northern Nigeria, several factors influenced the commencement of oil exploration activities in the Benue Trough and the Chad Basin. The most compelling of these factors was the discovery of oil and gas in the neighbouring countries of Chad and Niger Republics.
These countries share with Nigeria the stretch of the depression referred to as the central African rift system. In geological circles, the central African rift system is well known for its commercial hydrocarbon accumulation that spreads along its entire length.
Another factor, the diversification of Nigeria's exploration programme as a means of increasing her oil reserve base. The conviction of the Federal Government on the presence of oil in the Benue Trough and the Chad Basin, based on the similarity of features in the basins and sub-basins within the African rift system in geological setting, structure, age, faunal assemblage and organic matter quality, and quantity, led to the approval and allocation of 21 prospecting blocs. As a result, Shell, Chevron and Elf began oil exploration activities in the Benue Trough, for instance, on a production sharing basis in 1994.
The issue is not in contest that hydrocarbon exploration is a capital intensive project which requires very high level of technology and expertise. What is, however in contention, is the extent of exploration activities undertaken by the oil companies and the Nigerian National Petroleum Company (NNPC) in the Benue Trough and the Chad Basin.
Professor E.F.C. Dike of the Geology programme in Abubakar Tafawa Balewa University, Bauchi, disclosed that exploration in the Benue Trough, for instance, started when Shell Nigeria Exploration and Production Company limited (SNEPCO), Chevron and Elf, acquired acreages. According to him, these oil companies drilled one borehole each and abandoned them as dry holes. He also asserted that the SNEPCO well, Kolmani-1, was suspended and capped, which was an indication that the company found oil and gas.
The question here is: How possible is it, by any exploration standard, to conclude on the prospects of the Benue Basin, with just one well drilled in one concession area? There is also available evidence which suggests that all the companies involved in the oil exploration enterprise in the Benue Trough and the Chad Basin, drilled only shallow wells whose depths were not consistent with the average sediment thickness in the area.
Scientific studies have conclusively indicated that sedimentary rocks in the Benue Trough and the Chad Basin lie 6,000 metres below earth surface. However, the deepest wells drilled by the oil companies were less than 3,000 metres. The argument of the exploration companies is that, they submitted a work programme in which they ought to drill not more than 3,000 metres.
The pertinent question here is, who approved work programmes for the prospecting oil companies in such a highly technical project, without relying on the preliminary geological map and geo-physical survey report, which are supposed to guide the decision, particularly the depth of wells and their locations? If the geo-physical survey report indicated a 6,000 metres sedimentary pile for the region, why approve work programmes for only 3,000 metres drilling depths by the oil prospecting companies?
The long stretch of the Central African rift system contains sedimentary rocks that are said to be capable of generating and expelling oil and/or gas. The sandstones in Borno, Gombe, Yobe and Bauchi states in this long rift and marine depression are described in some reports, as hydrocarbon source rocks.
Another problem was the level of technology employed in the Benue Trough and the Chad Basin. The oil companies, according to source, employed the two dimensional method of seismic data acquisition (2-D) in the Benue Trough and the Chad Basin. They were the same technology employed in the Niger Delta with sedimentary pile of only 1,500 metres. However, in the 2-D method, which technology is one with least precision, highest error margin and low resolution lines are manually blended to produce seismic structures.
Yet, seismic operations have advanced from the error-prone 2-D through multi-components 3D, 3C, 4D, 4C to the very latest Q-system launched by Schlumberger. In these new systems, it is the computer which directly analyses the data to show structures which could be spotted for drilling.
The question then is, why employ the 2-D technology used in the Niger Delta where the basement rock can be accessed after 1,500 metres in the Benue Trough and the Chad Basin where the basement rock can only be accessed after 6,000 metres? Why employ the 2-D technology used in the Niger Delta where the age range of the rocks is 3 to 35 mm years in the Benue Trough and the Chad Basin where the age range of the rocks is 65 to 145 mm years?
From all available evidence, the oil companies could not encounter hydrocarbon deposits in the Benue Trough and the Chad Basin because of inadequate deployment of technology and the faulty work programme which sanctioned 3,000 metres drilling depth instead of 6,000 metres.
As such, Matori said the inability of the oil companies to strike oil in the North has nothing to do with the non-availability of hydrocarbon in the area. He said the exploration failed because of lack of modern technology and faulty work programme that sanctioned a drilling of less than 300m in a basin of over 500m of sedimentary rock thickness.
These are some of the unanswered questions which must have motivated the sixth Senate to revisit the issue as Senators Bala Mohammed, Abubakar Sodangi, Maina Lawal, Joseph Akaagerger, Gbemi Saraki, Smart Adeyemi, Mohammed Nazif, Muhammad Bello, Ayogu Eze, Mohammed Umar, Bukar Abba Ibrahim, A. Tafida and Munirudeen A. Muse lent their support to it.
Their demands included a request that the Federal Government include a supplementary budget in the 2008 fiscal year to cater for any financial commitment for research, consultancy, advertorial and other services that would lead to actual generation of public interest.
On the path of the House of Representatives, the Senate is on track. Honourable Shuaibu Hashimu Abdullahi, whose constituency (Awe, Keana and Doma in Nasarwa State) falls in the Benue Trough, said what the Senate was doing was in the interest of the country.
He said oil exploration in the North has gone beyond the "lack of political will" as held by some people, adding that it requires a collective approach by all stakeholders.
While geological findings reveal the prospects of oil and gas in the North, many still wonder why not much has been done to explore it.
Politician and Geologist, Alhaji Jibril Sabo Keana JSK, stated that there was no spirited effort at harnessing the resources in the North. The North, he argued has the largest basin in the country and scientifically, the basin allows for the trapping of substances for oil and gas.
The New Nigeria Development Company (NNDC) seems to be the only financial institution interest in the exploration. According to findings, it has spent over 400 million in the past two years on the four wells it acquired in the region, the amount; experts say is a tip of the iceberg in such ventures.
The company, Weekly Trust gathered, is also in to talks with Russian firm, Gazprom to the quest for the exploration of gas in the region.
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