Use of CO2 in Statoil's Bakken hydraulic fracturing operations expected to increase oil recovery while significantly reducing amount of water used. HOUSTON, April 21, 2015 /PRNewswire/ -- Statoil, an innovative international energy company, has demonstrated environmental and economic leadership by awarding a major carbon dioxide (CO2) supply and service agreement to Denver-based Ferus LP (Ferus), the premier provider of energized…