Photos & Diagrams

$Thermally-degradable Zonal Isolation Material (TZIM) swirls into AltaRock’s injection hopper, or DIVA (diverter injection valve assembly). Used during EGS stimulation, biodegradable plastic TZIMs block open fractures in the EGS reservoir, forcing water out into new zones during stimulation.$

$The hydroshearing process: Prior to stimulation, natural fractures in a geothermal well are kept tightly closed by the pressure from surrounding rock. During stimulation, high-pressure water pumped into the well induces very small amounts of slip along these fractures. The rough texture of fracture surfaces causes them to “self-prop”, or remain open, enough for water to flow through after stimulation.$

$AltaRock’s environmentally safe, thermally-degradable zonal isolation materials (TZIMs, or ‘diverter’) help isolate zones within a reservoir during stimulation. High-pressure water pumped into the well induces hydroshearing, opening up existing fractures in hot rock. Once a zone has extended around the wellbore, TZIMs are pumped into the fracture openings to block the zone. Continued pumping opens another zone of fractures. Once several zones have been created, pumping stops. As the well heats back up, TZIMs biodegrade and the fracture zones are opened to the wellbore. The result: a multi-zone EGS reservoir.$