Trials in Denmark of a prototype drilling tool could give hydrocarbon exploration companies a ’game changing’ technology, its developers claim.
The Badger Explorer is described by its Norwegian inventors as an autonomous ’fly-by-wire’ exploration tool that removes the need for fixed rig drilling, bringing with it the promise of huge savings in terms of time and money and its low impact on the environment.
Originally conceived in 1999 by Sigmund Stokka of Norway’s RIS-International Research Institute, up to eight Badgers will be taken to sea by boat, lowered over the side and guided to a drilling template by a remotely operated underwater vehicle (ROV).
The ROV takes Badger’s 10kV power and communication cables, which are spooled inside the tool, and secures them to a subsea power supply located near the drilling template. A further connection attaches the cables to a communications buoy. Continuous data from Badger’s sensors can be relayed via satellite to a receiver anywhere in the world, providing operators with a 3D survey of the area being explored.
Badger is lowered into a seabed-mounted drill jig or launch platform and it drills into the rock using an electrically-powered bit to loosen and crush the formation ahead of it.
It then drills vertically at an average penetration rate of two metres/hour, depending on the type of rock. Crushed debris is moved through the device and deposited in the space behind it, with the excess recompacted and forced into the rock formation through any fractures Badger has created. It is estimated that the tool will take around two months to penetrate 3,000m into the sea bed.
How the badger, above, will operate in co-operation with the power source, top left, and the ROV, top right
Badger Explorer ASA (BXPL) was formed in 2003 to take the technology to full commercialisation, and partners include Shell, ExxonMobil and StatoilHydro. Last December BXPL acquired 50 per cent of Falmouth-based Calidus Engineering, a specialist downhole engineering company whose expertise in mechanical, hydraulic and electronic systems has been employed extensively in the Badger Explorer Demo50, the prototype undergoing land trials in Denmark.
Nigel Halladay, Calidus managing director, saidthat a simple cross-section of the tool reveals a very complex piece of equipment.
’The functions of the tool are such that we have to power up all the hydraulics and drive some fairly substantial electric motors,’ he said.
’The tool has to clamp itself into position and then push forward on the drill bit so it is at the bottom of the hole. The bit is then rotated by electric motor, and the cuttings pumped to the top of the tool and recompacted. This all has to be accommodated in a 5in diameter tube.’
The harsh environment in which Badger operates adds to the challenge of designing the tool. Halladay said it will have to withstand very high temperatures. Further testing next year on the Demo125 version will seek to validate its performance at temperatures up to 125º C.
Despite the challenges, Halladay and Kjell Erik Drevdal, chief executive of BXPL, are convinced that Badger offers a viable alternative to conventional drilling in terms of profit and its low impact on the environment.
Drevdal claimed it lowers the risk of disturbing the marine ecosystem and is relatively non-polluting compared with traditional drilling methods, which require ships, helicopters and a rig to operate at sea for months at a time.
The claimed savings statistics are also compelling. it is estimated that Badger could shorten the time from discovery to development, and provide savings of between 60 and 80 per cent compared with current exploration methods.
’With Badger, we will charge a margin, maybe 10 per cent of what a full rig operation would cost,’ said Drevdal.
He added that the economics of any field — subsea structures, temperatures, pressure, the presence of oil or gas, and porosity — can be understood more quickly when deploying eight to 10 Badgers in a grid-like system.
’Many of the partners are referring to this as a “game changer”,’ claimed Halladay. ’It will have a major impact on the way oil exploration is carried out in the future.’