| 摘要 |
<p>The present invention discloses an apparatus and method for controlling a power tong unit having a power spinner and, in a preferred embodiment, three power jaws (12). The control system (10) controls grip pressure applied by a selected power jaw (12) to a first wellbore tubular to provide a relatively reduced grip pressure when the power spinner is activated to thereby rotate a second wellbore tubular at a relatively high rotation speed but with a relatively low torque. The control system (10) applies a relatively high grip pressure to two selected power jaws (12) used for applying high torque but a relatively slow rotation speed for final making up or initial breaking out of the wellbore tubulars with respect to each other.</p> |
