Basement Matters

One of the first geomechanics projects I ever worked on was in a fractured granite reservoir in Japan. The image logs were gorgeous. The natural fractures were abundant, and learning which ones were the most important was a (very geeky) thrill.

Tako Koning presented a fabulous poster in Calgary last week at GeoConvention 2019. It showed examples of oil and gas production from basement reservoirs in basins all around the world. It's a resource that is highly exploited in some places and virtually ignored in others. The reasons are varied - some geological, some economical, some geo-political. Fascinating stuff. One of the common criteria in exploring for these resources is that there's usually oil and gas in the overlying strata. Hmmm, sound familiar, Western Canada? What's exciting to me is the geomechanical relationship between the different reservoirs.

Basement faults are also an incredibly important aspect to understanding induced seismicity. In most places the earth's crust has been through multiple episodes of deformation, stress changes, overburden loading or unloading, glaciation and deglaciation, etc. All of this leaves a lasting mark in the form of faults and fractures. One needs to understand the geological history of an area to understand the role these faults and fractures play.

Anyhow, just some Tuesday musings. What's in your basement?