November 12, 2018
ST1 Lähienergia rents Y35 compressor to drill 7.2 kilometers of 500–600-meter deep wells.
Housing company, Asunto Oy Niittykumpu 3, in Espoo consists of three buildings with 124 apartments in total. Their annual district heating consumption used to be 1,200 MWh. The lifetime of the heat exchanger, utility service rooms and other technology was about to expire, and the housing company wanted to switch to more affordable, emission-free renewable energy. However, traditional solutions were out of the question due to the West Metro project.
Together with the client's consulting firm Sweco, St1 Lähienergia found a solution — a combination of deep wells, heat pumps and heat recovery ventilation (HRV). They drilled a total of 7.2 kilometers of 500–600-meter deep wells using St1 Lähienergia's own deep drilling equipment. Some of the wells were drilled diagonally underneath the metro tunnel. By using a combination of diagonal drilling, deep wells, and HRV, they were able to reduce the surface area of the well site to one third of the traditional size, explains Kristian Savela, CEO of St1 Lähienergia.
They used Atlas Copco Rental's Y35 oil-injected air compressors, which are specifically designed for supporting drilling equipment. Drilling with a pressure of 35 bar allows more meters to be drilled per hour, with lower overall costs per meter. By using a DrillAir Y35 compressor, daily drilling depths can reach 500 meters. St1 Lähienergia has even drilled holes that are 1.5 km deep by utilizing Atlas Copco Rental's high-pressure boosters, which can produce pressures of up to 155 bar.
We have been very satisfied with Atlas Copco Rental's compressors. They have enabled us to minimize drilling hours, which is important when drilling at a housing company site. By using different boosters, we have been able to pilot various deep-drilling techniques and equipment combinations. The rented equipment has always been reliable, and we have always received support when needed.”
The Y35 compressor produces oil-injected air in streams of up to 35 bar and 40 m3/min. The compressor is equipped with a powerful Stage IV motor that helps to reduce harmful emissions. The Stage IV motor reduces particle emissions and NOx content by 50–96% more than previous models. It also consumes significantly less fuel, and can provide air for various industrial uses while maintaining optimal efficiency regardless of streaming speed.
Learn more about the Niittykumpu project (in finnish language only)