| 摘要 |
<p>The tubing injection apparatus of the present invention includes a frame upon which is mounted a pair of opposed endless flexible conveyor members (50,52). The conveyor members have opposed elongated parallel runs spaced apart to form a path for engagement with the tubing by gripper blocks disposed on the conveyor members. The conveyor members are trained over spaced apart drive sprockets (58,60) and idler wheels (54,56). Rollers (170) are reciprocally disposed on the frame adjacent that side of the opposed elongated parallel runs opposite the path and adapted for engagement with the gripper blocks. The conveyor members include two strands of chain having projecting pins. The gripper blocks are mounted on the projecting pins such that the surface of the projecting pins is coincident with that surface of the gripper blocks which engages the rollers. Hydraulic piston and cylinder assemblies (172,174,176,178) inserted on the frame have rams (182,184,186,188) adapted to engage the rollers (170) so that the rollers may engage the gripper blocks upon actuation of the hydraulic piston and cylinder assemblies. The piston and cylinder assemblies are connected to a common fluid pressure source. The rollers apply a varied force against the gripper blocks such that the gripper blocks grip that portion of the tubing along the path adjacent the well with less force than that portion of the tubing on the path further away from the well. <IMAGE></p> |
