Patent ID: 7552890

Claim:
A wheel tensioner assembly for applying tension to a string of coiled tubing during its injection into and withdrawal from a wellbore, the wheel tensioner assembly comprising: (a) a selectably rotatable tensioner wheel having a circumferential contact surface for interacting with a first side of the coiled tubing; (b) a holddown device comprising (i) two side frames, wherein each side frame mounts a set of plate guides, and (ii) a plurality of roller mounting structures, wherein each roller mounting structure mounts a contact roller, a first end sheave on a first side of the contact roller, and a second end sheave on the second side of the contact roller and wherein each roller mounting structure is reciprocably positioned between two plate guides of each side frame; and (c) a biasing mechanism for urging said contact rollers radially inwardly to bear against the second side of the coiled tubing and press the coiled tubing against the circumferential contact surface of the tensioner wheel, wherein the biasing mechanism includes a first tensioning cable in communication with the first end sheave of each roller mounting structure and a second tensioning cable in communication with the second end sheave of each roller mounting structure.