| 主权项 |
1. The method of automatically maintaining a relatively constant tension and a relatively constant slippage load on an umbilical, which is deployed from a spool on a reel by being clamped to a subsea drilling riser where said relatively constant tension is determined by a motor torque on a motor and said relatively constant slippage load is determined by a frictional load on one or more slip clutches, comprising:
determining an initial radius to said umbilical on said spool, the diameter of said umbilical, the distance between a first side flange and a second side flange of said spool, and a distance of said umbilical from a first side flange of said spool;
determining a direction of rotation of said spool;counting the rotations of said spool; and calculating approximately when said umbilical moves to another layer and changes a radius to said umbilical. |
