Monday, January 30, 2017

KFSM Earthquake Insurance Interview

Just finished an interview with Charlie Hanna of KFSM channel 5 in Ft. Smith, AR. Topic was earthquake insurance. It will air sometime in the next couple of days. Below is my whiteboard drawing made for the interview.

Explanation of the figure: In N and NE Oklahoma horizontal wells are drilled into unconventional reservoirs, typically the Mississippian Lime. These wells produce vast quantities of formation (salt) water mixed with a small percentage of oil. The oil is separated and the water needs to be disposed. For this purpose a deeper nearby vertical salt water disposal well pumps the water down into the 500 million year old Arbuckle formation that sits on granite basement rocks. The basement and Arbuckle often have ancient inactive faults from continental collisions that formed the North American continent. Salt water injection that is too rapid, at too high a pressure or from wells too close together can reactive the faults and be felt as earthquakes. The earthquake waves radiate out from the fault and, sometimes, can be felt 100 miles away in Fayetteville, AR where I live. The hilly terrain of NW Arkansas scatters and focusses the earthquake waves so that the felt effect varies widely from one neighborhood to the next.

Sketch of NE OK earthquake as felt in Fayetteville, AR

1 comment:

wandreef said...

I saw the graph on LinkedIn and followed you here to this story. It's very interesting.
Has no one ever criticised you for it? It's an area of "vigorous discussion" in the geoscience. I would like to hear your interview and ask you why local topography may change how an earthquake is felt. A simple explanation is fine but if you have a paper or online reference I'd like to look at it. I completed an undergrad in Calgary in Geology in 2001 but just-made-it through the geophysics requirements. I've been researching and learning about intracratonic earthquakes in my local area in the Peace River Arch area of northern Alberta. Love your books as well. I'm also a collector of old books but not of geotexts.