Monday, 26 September 2011

Monitoring a Frack Job...

Ever want to know what frack job looks like? Here's a video:

What is this video showing, I hear you ask? This is a plot of all the microseismic events occurring during a frack-job. As the fluids are pumped in, the rock begins to break and fracture. The fracturing releases seismic energy. In many ways this process can be considered analagous to earthquakes, except they are many orders of magnitude smaller. Hence they are referred to as microseismic events.

Geophysicists place geophones in the ground near to the region of interest. These geophones detect the P and S-waves produced by the microseismic events, allowing us to compute their locations. We use their locations to create a picture, showing where the fractures have gone during the frack job.

This video is a map view of event locations. The injection point is at (0,0). The events track the formation of a fracture zone approximately 300m long, with a strike of 080 degrees, over the course of the frack job (in 3 stages, over 10 hours in total, from 7 in the morning to 5 in the afternoon).

Acknowledgements for this video to Andreas Wuestefeld, my colleague at Bristol University.

If you want to ask a question about this video, do post a quick comment.