What is Fracking?
Fracking is the short form derived from the term hydraulic fracturing. The term fracking refers to how the rock is fractured apart by the high pressure mixture. This is a type of drilling that has been . Thanks to major technological advances , is responsible for swelling U.S. oil and natural gas production. Since the US began intensively using it since 2010, the oil produced has increased from 5mb/d to 9mb/d. The process is being considered in the UK and is mostly at its exploration stages having faced much opposition from environmental pressure groups.
How does it work?
Once a shale rock is identified, hydraulic fracturing is combined with horizontal drilling to tap oil from shale and other tight rock formations. This is done by drilling a mile or more below the surface before gradually turning horizontal and continuing several thousand feet more. There therefore can be multiple wells accommodated on a single surface site.
After drilling, the well is cased and cemented and thereafter perforations are made on the horizontal part of the well pipe. A mixture of water, sand and additives (in a ratio of 90%:9.5%:0.5% respectively) is then pumped at high pressures to create micro fractures within the rock. The additives perform the following tasks.
– Reduce friction (hence reduced pump pressure)
– Prevent corrosion of the pipe (hence improved well efficiency).
Stay tuned next week for the next series on why fracking is done!