OPEN HOLE TRACTOR WITH TRACKS

摘要

A downhole tractor (10) is provided that may be used in open or cased wells, and is also designed for use in open holes having a variety of soil/formatio n consistencies (e.g., soft, firm, rigid, etc.), varying diameters and non- uniform and irregular bore profiles. The tractor may include a track assembl y (28) including a plurality of idler wheels (34) and a continuous track (30) rotatably disposed around the idler wheels. A motor (22) may be adapted to rotate the track around the idler wheels. Upper (36) and lower (38) arms may be pivotally connected to opposite ends of the track assembly and pivotally connected to a tractor housing (26). An actuator arm or link assembly (44) m ay be provided to impart an outward force to the track assembly to move the tra ck assembly outwardly into an open position and a retracting force to retract t he track assembly into a closed position. A rotatable screw (42) may be connect ed to a second motor, or a rod may be connected to a hydraulic system, to actua te the actuator arm or link assembly.