A blowout occurs when a formation of fluids, like water, gas, oil, or a mixture of the three, flows in an uncontrolled fashion from a well.  Would a large scale containment berm be useful? Remediation at the locations of blowouts cost an exploration company millions of dollars to deal with.  There are companies that do blowout spill containment and remediation for sites that have experienced an uncontrollable spill situation.  Blowouts require large scale spill containment and remediation.  Backflow is a good symptom that indicates a blowout may happen. A good example of a blowout is seen in this video.