Tools We Use: AltaStim
One of the most important steps in the EGS demonstration process comes after we’ve created the EGS reservoir, that network of water-filled cracks below the surface, which will be used to heat injected water. We need to drill production wells into that reservoir in order to get the water out. But determining exactly where to drill it can be quite complicated.
In advance of stimulation (the process that creates the cracks), we can only model the shape and size of the EGS reservoir. A model is necessary in order to help with planning initial production well paths and estimate the amount of water to inject.
To do that, AltaRock has developed a modeling software program called AltaStim. AltaStim uses information we’ve collected about the geothermal, geochemical, mineralogical, and strength attributes of the rock within the demonstration site to create a model of what the fracture network underground looks like.
AltaStim maps the projected fracture network and generates a hypothetical microseismic event map around the well bore, showing us the size, location, and orientation of the predicted fracture system. As with any modeling tool, the results won’t match reality, but they are a scientifically-based approximation.
After stimulation, the microseismic array (MSA) we will provide an actual microseismic event map around the well bore. This actual map will help refine the current plans about where to drill the production well into the fracture network. The MSA will be the topic of a future blog post.