energy alternative

AnTech sets sights on clean energy alternative
by: OilOnline

AnTech Ltd is exploring alternative sources of clean energy, particularly underground coal gasification (UCG).

The Role of Drilling and Well Completion
Recently, Toni Miszewski, Managing Director of AnTech, presented a session entitled "Drilling processes for UCG: coiled tubing drilling and well completion" at the Underground Coal Gasification training conference sponsored by the UCG Partnership in association with Imperial College London. The week-long event, which was limited to just 25 participants, took place at Imperial College London, and was attended by individuals from a range of disciplines and industries.

The Clean Energy Alternative
As the quest for energy alternatives continues to rise, UCG is considered one of the cleanest resources in development. It is the process of converting un-worked coal into a combustible gas, which can then be processed to provide a source of clean energy with minimal greenhouse gas emissions. The process involves drilling two wells into the coal. The first well is drilled for the purpose of injecting oxidants that allow the chemical reaction to occur within the coal. The second well is used to extract the gas.

UCG Offers Wide-ranging Benefits
Not only does UCG create the potential to extend coal reserves, it makes it possible to exploit reserves that were previously thought to be uneconomic using conventional methods of extraction, or because the reserves were inaccessible due to depth or the geological make-up of the location in which the coal was situated. According to Miszewski, operating costs and the amount of capital required to carry out UCG is potentially much lower than traditional extraction methods. "Because less human interaction is required to carry out the process, it means that health and safety levels are higher," said Miszewski. "In addition to reduced costs and improved safety levels, perhaps the most dramatic benefit of UCG is the impact on the environment, which is minimal. With UCG, there is no need to stockpile the coal, dispose of waste produced as a byproduct, and the amount of CO2 released into the atmosphere is typically well within the strictest of environmental regulations."

AnTech COLTÔ BHA Offers Drilling Accuracy Required for UCG
How does AnTech's downhole technology fit into the picture? Currently, there are two different methods of UCG that have evolved, both of which are commercially available. The first method, which is based on technology developed in the former Soviet Union, uses vertical wells and a method similar to reverse combustion, which opens internal pathways in the coal. The process was tested using air and water as the injected gases in Chinchilla, Australia from 1999 to 2003. The success of this five-year testing programme led to a great deal of interest in UCG, particularly in light of the controlled shutdown programme in 2003, which involved the gasification of 35,000 tonnes of coal.

The second method, which has undergone extensive testing in European and American coal seams, lends itself particularly well to the use of AnTech's COLT, the company's award-winning bottom hole assembly. This approach creates dedicated inseam boreholes using drilling and completion technology adapted from the oil and gas industry. The drilling technology features a moveable injection point known as a CRIP (a controlled retraction injection point), which typically uses oxygen or enriched air for gasification. The inseam borehole must be drilled with great accuracy, and as close to the bottom of the coal seam as possible. By drilling the borehole along a specific line, it makes it possible to precisely control the reaction process, thereby ensuring that maximum production is achieved. Because the COLT is compact and easy to control, it can be manoeuvred in such a way that accurate drilling of the inseam borehole is achieved, effectively and economically. Coupled with the reduced cost of UCG, using the COLT to drill the borehole seams makes the solution commercially viable. A further benefit of using the COLT is that rapid build rates and extremely quick set-up mean that the overall cost of the UCG operation could be further reduced.

Call for UCG Drilling Partners
AnTech is currently conducting a search for companies interested in the possibility of using the COLT to carry out field tests or for commercial operations. Given the renewed enthusiasm and range of research trials carried out around the world in Asia Pacific, Europe and North America, AnTech is keen to work in cooperation with a forward-thinking partner to take the UCG process to the next level.