What is a Blowout?
In this video, we define what a blowout is, causes of a blowout, mitigation techniques, effects, and more. In case you don’t have time to watch the video, below is a summary:
- A blowout occurs when any amount of oil or gas is released uncontrollably from the well.
- In today’s times, a BOP or Blow out preventer is installed on every well during drilling operations to prevent from such blowout from happening.
- There are several factors that contribute to causing blowouts, all of which drillers to mitigate and detect early.
- The first thing to realize is that the formations we drill through have a natural pressure to them and some of the most dangerous ones are over pressured compared to the other formations around it. So, when we drill through pressurized formations, we commonly counteract this pressure through the use of drilling mud, which applies a hydrostatic pressure to the reservoir rock. If this balance is upset, water, gas, or oil can infiltrate the wellbore itself – a phenomenon known as a “kick” – and this can quickly escalate into a blowout if not promptly identified and addressed. If a kick is detected, the first thing that must be done is to shut in the well, thus reducing the chances of a blowout. A heavier fluid will then be introduced to try and raise the hydrostatic pressure and achieve a balance. Meanwhile, the fluid or gas that infiltrated the wellbore will slowly be evacuated in a controlled and safe manner. If a kick goes uncontrolled, then it can lead to a blowout.
- There are three main types of blowouts that you may hear about in the oil and gas industry.
- Surface Blowout: most common type of blowout. Damage is seen on the rig and can cause major damage.
- Underground Blowout: an uncommon blowout where fluid from deep, high-pressurized formations flow upwards to a shallow, low-pressurized formation (can occur where the casing has not been set)
- Underwater Blowout: blowouts that occur offshore. (BP Macondo in 2010) due to their location, these are very difficult to deal with.
- Why do we care about blowouts? Blowouts can lead to great disasters that include personnel loss and environmental destruction.
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