| 摘要 |
A method to be used when performing drilling in a well bore, comprising: . - positioning in the well bore a drill string (6) comprising at least two pipe conduits (6a, 6b), an upper end and a lower end comprising a drilling tool (8a), thereby forming an outer annulus (11, 12) between the well bore wall and the drill string; . - drilling a well bore section comprising at least one u-shaped section; . - feeding a first fluid with a first density into the outer annulus (12) above the u-shaped section, . - providing a second fluid with a second density within the drill string (6) and around the tool (8a); . wherein the first density is larger than the second density is disclosed. . A device for performing the method is also described. |
