Unpowered casing gas recovery structure

• Main Authors: ZHAO SONGHE, WANG XIAOJUN, SUN QUANYOU
• Format: Patent
• Language: Chinese; English
• Published: 16.11.2018
• Subjects: BLASTING; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; POSITIVE DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS; WEAPONS

The invention provides an unpowered casing gas recovery structure. The unpowered casing gas recovery structure comprises a first cylinder barrel, an intermediate, a second cylinder barrel, and a hollow piston rod, wherein the first cylinder barrel, the intermediate and the second cylinder barrel are connected, and a hollow piston rod is arranged in the first cylinder barrel, the intermediate and the second cylinder barrel in a penetrating mode. First and second pistons are arranged on the two ends of the piston rod, an air pressure balance duct is arranged on the intermediate, and an air filter which ensures the air communicating with a rod cavity of the second cylinder barrel is arranged on the side, away from the rod cavity of the second cylinder barrel, of the air pressure balance duct;a gas outlet and a gas inlet are arranged on the intermediate, a first non-return valve for controlling the casing gas in a rod cavity of the first cylinder barrel discharging is arranged in the gasoutlet, and a second non-r