Edwin Lawrance's blog

Usually
when the well reaches its economic limit the operator plugs and abandons it.
But the risks and hazards that can happen due to this are neglected. Gas leak
from one of the plugged wells of Elgin gas field shows that abandoned wells can
cause serious threats. With this incident which occurred recently shows that, accidents
can happen even if we have methods to completely seal or plug a well. No human
life was threatened by this accident, but oil and gas leaks from the abandoned
wells can cause serious environmental impacts. Reason for the gas leak in Elgin
field was due to the outdated plugging method used to seal the well by Total.

In this energy demanding world the need for fossil fuel never declines. Depletion is an unavoidable part of hydrocarbon production and all the reservoirs around the globe faces this. Depletion due to hydrocarbon production can also pose threats that can even make a scar on the earth's face. 

1) Land subscidence

2) Fault reactivation

3) Earthquakes

4) Casing damages

5) Formation damage

and further more...