Blowout (well drilling)
When these high-pressure zones were breached, the oil or natural gas would travel up the well at a high rate, forcing out the drill string and creating a gusher.
[4] One dramatic account of a blowout and fire reads, With a roar like a hundred express trains racing across the countryside, the well blew out, spewing oil in all directions.
Casings wilted like lettuce out of water, as heavy machinery writhed and twisted into grotesque shapes in the blazing inferno.
[6] The BOP valve affixed to the wellhead could be closed in the event of drilling into a high pressure zone, and the well fluids contained.
[1] Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights, and other organic compounds, found in geologic formations beneath the Earth's surface.
But if the well is not shut in (common term for the closing of the blow-out preventer), a kick can quickly escalate into a blowout when the formation fluids reach the surface, especially when the influx contains gas that expands rapidly with the reduced pressure as it flows up the wellbore, further decreasing the effective weight of the fluid.
Conversely, if the rate of returns is slower than expected, it means that a certain amount of the mud is being lost to a thief zone somewhere below the last casing shoe.
[citation needed] The first response to detecting a kick would be to isolate the wellbore from the surface by activating the blow-out preventers and closing in the well.
Then the drilling crew would attempt to circulate in a heavier kill fluid to increase the hydrostatic pressure (sometimes with the assistance of a well control company).
In addition to oil, the output of a well blowout might include natural gas, water, drilling fluid, mud, sand, rocks, and other substances.
If the flowing gas contains poisonous hydrogen sulfide, the oil operator might decide to ignite the stream to convert this to less hazardous substances.
[citation needed] Sometimes blowouts can be so forceful that they cannot be directly brought under control from the surface, particularly if there is so much energy in the flowing zone that it does not deplete significantly over time.
[24] Contrary to what might be inferred from the term, such wells generally are not used to help relieve pressure using multiple outlets from the blowout zone.
Blowout preventers (BOPs) are the primary safety devices designed to maintain control of geologically driven well pressures.
After the Macondo-1 blowout on the Deepwater Horizon, the offshore industry collaborated with government regulators to develop a framework to respond to future subsea incidents.
[32] In the event of a subsea blowout, these plans are immediately activated, drawing on some of the equipment and processes effectively used to contain the Deepwater Horizon well as others that have been developed in its aftermath.
In order to regain control of a subsea well, the Responsible Party would first secure the safety of all personnel on board the rig and then begin a detailed evaluation of the incident site.
Remotely operated underwater vehicles (ROVs) would be dispatched to inspect the condition of the wellhead, blowout preventer (BOP) and other subsea well equipment.
[33] If shutting in the well could introduce unstable geological conditions in the wellbore, a cap and flow procedure would be used to contain hydrocarbons and safely transport them to a surface vessel.
On Sep. 30, 1966, the Soviet Union experienced blowouts on five natural gas wells in Urta-Bulak, an area about 80 kilometers from Bukhara, Uzbekistan.
When the device was detonated, it crushed the original pipe that was carrying the gas from the deep reservoir to the surface and vitrified the surrounding rock.
