The theft of oil from the thousands of kilometres of pipelines that criss-cross Nigeria has now got so bad that it accounts for the abstraction of 200,000 barrels a day – representing 10% of the resource-rich country’s total production.
Oil bunkering, as it is known, is a highly dangerous yet relatively straightforward criminal act. Organised gangs cut into buried pipelines with hacksaws and blades. When the companies see the pressure drop on their lines, they reduce the flow momentarily, giving thieves time to attach spigots to the lines. As the pressure is ratcheted back up, the thieves then siphon some of the oil out of the line for refining or sale abroad.
The impact of oil bunkering is three-fold. Nigeria’s oil exports and revenues are reduced, meaning less investment in areas such as health and national infrastructure. It causes enormous ecological damage, with crude gushing onto agricultural land. And then there is the human cost: there have been individual cases of oil bunkering that have resulted in the death or injury of hundreds of people at a time. No wonder the Nigerian government and the energy companies are desperate to stop it from happening, or at least lessen the impact of each incident.
Now a small British engineering company is about to take centre-stage in the battle against the thieves. TBG Solutions, a Chesterfield-based bespoke hardware and software provider employing 30 engineers, has developed a pipeline monitoring system that uses vibration sensors to pinpoint the site of oil bunkering events, so that energy companies can react more effectively.
The technology is about to be trialled on a 27km stretch of pipeline in Nigeria that has been the subject of frequent attacks. Should the trial go well, says Paul Rawlinson, co-founder of TBG, the company’s technology could be adopted across the country, resulting in tens of millions of pounds of exports.
“The budget for the trial has just been authorised by the Nigerian government and we expect our system to be deployed in the first half of next year,” he says. “It’s a huge opportunity. There are thousands of kilometres of pipelines in Nigeria, and we are talking about installing our sensing technology every 3-5km. If we get 10-15% active monitoring of the pipes, then we are talking in the order of £100 million worth of business.”
The starting point for developing TBG’s pipeline monitoring system was the limitation of existing technologies. Most oil pipelines in Nigeria are fitted with a fibre-optic cable which requires a laser source every 40km. Thieves can see the cable, making it easy to cut at both ends. “As soon as that is done, the pipeline operator has no idea where the attack has happened across that stretch of pipeline,” says Rawlinson.
TBG’s solution is more discreet, being concealed at intervals along the pipeline. In terms of hardware and software, the system comprises intelligent nodes that are spaced 3km apart along the length of the pipeline. Each node is fitted with two accelerometers that are used to detect vibration, either from its left or right, accurately distancing any events above a certain threshold to within a couple of hundred metres. The data can then be packaged on-site and sent via satellite communication to an operations centre, with a suitable fast response team being dispatched.
The CompactRio can operate in temperatures between -20ºC and +70ºC
“The sensors will be positioned every 3km, but they can measure across 20km of pipeline,” says Rawlinson. “So if for whatever reason a couple of units get taken out, there is adequate redundancy to ensure that the system can continue to send meaningful data back to the operations centre.
“Each node has two vibration sensors, and they are all time-stamped. By determining which sensor records an event first, and by analysing the amplitude of that event, we can work out where it is happening,” he says.
At the heart of the TBG system is National Instruments’ CompactRio programmable automation controller, combining a realtime processor and a field-programmable gate array (FPGA). The system uses a four-slot chassis containing the vibration modules and links to satellite communications, with analysis running on the FPGA.
“The software works really well with the hardware, because National Instruments has spent a lot of time and money making sure both sides are 100% compatible,” says Rawlinson. “It’s an embedded solution, and that means there’s a bi-directional link, so we can flash upgrades to all of the units while they are in-situ.”
Rawlinson describes the technology as having ‘deployed intelligence’. That means much of the data is analysed and packaged in the field, saving on transmission costs. “There is a real concern about the high cost of sending data over satellite communications networks, with operators keen to reduce the amount of data that is relayed back,” he says.
“The analysis is being done at the point of measurement, and, if there are no events, the system just sends an intermittent heartbeat until something actually happens. You are not sending redundant data. The calculation work is being done by the CompactRio system in the field.”
Although the Nigerian trial is yet to begin, TBG is already looking at improving the technology. Originally the system was to be provided with batteries as a power source. But these would have needed changing as regularly as every two months, presenting a significant security risk for operational staff. So an ethanol fuel cell has been identified, which will require refuelling every two-and-a-half years.
TBG is also looking at energy harvesting technologies that could provide power from the vibration caused by the transfer of the oil along the pipeline.
“Trickle charge doesn’t give us a huge amount of power but it is something that will allow us to extend periods between on-site refills,” says Rawlinson.
He is hopeful that the technology could be applied to other sectors. “There could be an application in the offshore sector, specifically the assessment of the damage caused to pipelines by trawler activities. A vibration response, using ultrasonics rather than satellite communications, to measure how much wear pipelines are taking could prove to be very useful,” he says. “It could also be used to measure pressure and temperature. You would just need to add a couple more modules and a bit more software.”
There are no major restricting temperature parameters, Rawlinson adds. “CompactRio in its normal configuration can operate between -20°C and +70ºC, and with thermal coating it could be lower or higher than that.”