Safety under-well short joint for air drilling well

• Main Author: RUOMING,LI CHEN
• Format: Patent
• Language: English
• Published: 25.07.2007
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

A safety short section used in underground of air drilling well comprises a body(1), a valve base(2), a thermal sensitive valve stem(3) and a spring(4), and a baffle(5) with the valve base (2) and a baffle(5) arranged inside of an internal cavity of the body(1) by screw thread, the thermal sensitive valve stem(3) of a semi-spherical upper end arranged between the valve base (2) and the baffle(5) and the upper end of which is matched with inner cone surface of a lower end of the valve base(2). A step is arranged at circular-shaft shape bottom end of the thermal sensitive valve stem(3) and the lower end of which is connected with the inner hole of the baffle(5) by way of clearance fit. The utility model has advantages of simple structure and convenient use. When the underground temperature of the well reach a preset temperature, rigid steps of the thermal sensitive valve stem(3) extends to an upper surface of the baffle(5) and at the same time the upper semi-spherical surface of the thermal sensitive valve stem(3) and the lower inner cone surface of the valve base(2) are in a seal formation in order to shut an air way to assure an automatic flameout because of hypoxia and guarantee underground safety.