Considering the way in which we are so immersed in the fact that we are an oil producing country, one would have thought that any prospect of discovering more oil within our borders would be one that the government would jump at. The acceptance by academic experts and geologists in the oil and gas sector that hydrocarbon deposits are believed to be heavily present in the Lake Chad Basin and the Benue Trough has for years been treated with complacency by the Nigerian government.
The Lake Chad Basin found in Central Africa, covers an area of almost 8% of the continent and spreads over seven countries, with Nigeria occupying at least 21% of it in Maiduguri state. The Benue Trough is a major geological formation underlying a large part of Nigeria and extending about 1,000 km northeast from the Blight of Benin to Lake Chad. It is documented that the Chad basin has been forming for thousands of years and for all that time, evidence of crystalline rock has been found under the more recent deposits.
A couple of years of ago, it came to light that the Republic of Chad and Niger, countries that have contiguous landmass with Nigeria had found substantial deposits of crude oil and commercial exploitation of the mineral is ongoing in its own sector of the Lake Chad Basin. This prompted Nigerians living along Lake Chad to question why more effort was not made by the Nigerian government to commit to exploring for oil and gas in commercial quantities on its side of the basin. This was seen as an encouraging pointer to the prospects of oil discovery in the Nigerian side of the basin. Oil prospecting in those countries had lasted for close to two decades, but the companies had remained steadfast in their belief that the geology of the territory held tremendous promise. Instructively though, the cost of the prospecting activities had been borne by the oil firms without any injection of funds by government.
Although in the past oil exploration in the Lake Chad had been commissioned by the Nigerian government, it is believed that the wells dug did not reach the required depth and it was effectively stopped under controversial circumstances. The NNPC which carried out the search for oil in the Lake Chad from 1976 had said that the drilling campaign was halted because of the low success rate in the discovery of hydrocarbon deposits in commercial quantity. But researchers and experts of oil exploration in northern Nigeria have in the past been quoted as saying that there is 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 meters below the earth surface. However, the deepest wells drilled by the oil companies reached depths of less than 3,000 meters.
The argument of the exploration companies is that, they submitted a work programme in which they proposed to drill not more than 3,000 meters. 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 as to the depth of wells and their locations. If the geo-physical survey report indicated a 6,000 meters sedimentary pile for the region, why approve work programmes allowing only 3,000 meters drilling depths by the oil prospecting companies?
In March 2003, in an effort to resume the search for oil in the area, the Federal government commissioned a consortium of indigenous and international consultants to carry out what it described as an integrated study in order to evaluate the large volume of data generated over the years and to provide a guide for future exploration activity in the Chad Basin and Benue Trough. The integrated study was aimed to review the entire exploration strategy and come up with new exploration approach considering all the geological peculiarities of the Basin. But not much information has been publicised as to what the study has uncovered.
Geologists in the Nigerian Universities have expressed the view that even though there is limited data on the exploration activities in the Chad basin and the Benue Trough, available evidence suggests that the Nigerian side of the Chad Basin and the Benue Trough has positive drillable prospects. With the prospect that the geology and the structural setting of the Nigerian side of the Chad Basin and the Benue Trough and looking at all the parameters of the exploration for the hydrocarbon, the conditions are there for the presence of commercially viable hydrocarbon.
On the other hand, some experts in the field refer to the uncertainty of drilling in the areas due to what is referred to as the “oil window” for each sedimentary basin. Apparently, indications are that the oil window is in the 3,000 metre range for both the Chad Basin and the Benue Trough. This would indicate that drilling deeper at 6,000m might not yield huge amounts of oil and gas. Nonetheless, whatever found, no matter how small would be beneficial and significant.
For a while, doubts have been expressed especially in the north as to whether the Federal Government and the NNPC have the commitment and the capability to carry out this project. Questions surrounding whether the NNPC invested enough funds in seismic data acquisition and drilling in these areas or whether the cessation of oil exploration in the Lake Chad Basin and Benue Trough is related to geopolitical issues in the country will continue unless more effort is made.
Nigeria needs a fresh programme for interested oil prospecting companies that would insist that drilling depths must reach deeper meters, coupled with the employment of the most modern and latest technologies to reappraise all the fields that had been earlier written off as uneconomical based on 2-D seismic data computation. Ghana’s recent oil discovery after 20 years of failed attempt is a clear example where the employment of the latest technology in oil exploration endeavours has yielded positive results, despite initial claims of non availability of hydrocarbons in the area. It is therefore safe to conclude that the non implementation of the recommendations suggested will only confirm the politicisation of oil exploration activities in the Chad Basin and Benue Trough, through the lack of political will and inadequate application of resources to the search for hydrocarbon in all parts of the country
Without doubt, finding oil in the Chad Basin and Benue Trough area will require new thinking and the re-focusing of the entire efforts of the NNPC. Any new strategy will involve addressing the presently identified constraints which primarily is the residency of the project within a small department in the NNPC, among so many other schemes. If any commitment made beyond the prolific Niger Delta Basin towards the exploration of oil in these areas and basins with good sedimentation is successful, in addition to the Niger Delta, other oil producing states could include, Maiduguri, Niger, Anambra, Adamawa, Benue, and Sokoto basins which are located alongside the Middle and Lower Benue Trough. If oil is discovered in these areas, it will be able to be exploited for the benefit of all Nigerians. And collectively we can all sing, ‘oil, oil everywhere in the South-South, East, West, Middle Belt and North’.