Technology and equipment of preventing gas overrun in drilling operation of outburst coal seam

Abstract

Aiming at the problem of gas gushing hole during the construction of through layer drilling(hydraulic punching), the factors that easily cause gas overrun in the working space during the hydraulic punching operation are analyzed and determined. Starting from solving the sealing problems of the key points such as the orifice blowout preventer, drill pipe blowout preventer, gas gathering box slag discharge place and drill pipe tail, the blowout prevention device at the orifice is developed, and the automatic control of separate source drainage is adopted to solve the reasonable matching of pumping capacity. The blowout preventer innovatively adopts the integrated seal of leather pad and brush, which has a good sealing effect. The gas buffer device is designed to buffer and store gas, and effectively reduces the gas impact pressure in the blowout preventer. At the same time, according to the feedback from the site, the size, materials and other aspects are continuously optimized to improve the portability and durability of the blowout preventer, forming a perfect anti-overrun technology and series of equipment for cross layer drilling construction (hydraulic punching).

Keywords

• drilling construction
• hydraulic punching
• gas overrun
• blowout preventer
• extraction flow control