| 摘要 |
FIELD: well-boring equipment. SUBSTANCE: string of piping has one or more spiral pipes, which have no less than one coil with left screw line and calculated curvature radius of spiral pipe portion, which provides minimal radial space between well wall and operating string and surface of spiral pipe portion. String of piping consists of either several spiral pipes, or alternate straight and spiral pipes, when straight end portion of each spiral pipe has length of no less than 1 meters. EFFECT: better boring and well operating conditions. 2 dwg |
