What causes a well blowout?

What we call oil well blowout,may be a phenomenon during which fluid from the formation spew to the bottom or flows into other formations within the well, mostly within the oil and gas extraction site. Uncontrolled blowout refers to a blowout that can’t be controlled even with a capping device. An uncontrolled kick can quickly deteriorate into a blowout. Blowout may be a normal phenomenon, but the occurrence of blowout accidents, gas and oil ejected after friction with air, contact with fire susceptible to combustion, will burn equipment and burn staff; If a blowout occurs during a sulfur well , sulfide gas within the formation diffuses into the air, which isn’t easy to regulate and can cause great harm to the physical body , so it’s very dangerous.

There are many reasons for a blowout:
1. First direct explanation for blowout
(1) Decrease of kill fluid density caused by gas invasion or water injection;
(2) Weak sense of control and paralysis of thought;
(3) The well wasn’t enclose decisively after the kick was found, leading to the injection potential was too fierce to enclose the well
(4) No blowout preventer is installed at the wellhead;
(5) The installation of blowout preventer system is unqualified;
2. Second geological reasons
(1) Lack of adequate understanding of the oil and gas content of underground strata, especially the distribution of gas layers. within the current widely used balanced pressure operations, there’s a big safety risk if the drilling hits the gas zone.
(2) Formation pressure changes caused by upward migration of manufacturing gas because of casing damage, fracturing operation or forced injection and production during oilfield development, especially within the later stage of oilfield development.
3. Thirdly management and technical reasons
(1) Insufficient attention has been paid to the first monitoring of kick;
(2) the power of the crew to cater to emergencies isn’t strong;
(3) Post responsibility Well control measures haven’t been effectively implemented on site.
I use method,is to fill the well with dense barite powder to extend pressure and stop the blowout.