| 摘要 |
A derrick assembly (1) is described, the derrick assembly (1) including a derrick (11) and a gripping deck (13) which includes a holding device (131) for holding a casing (2), the derrick assembly (1) being characterized by further including a lifting device (12) arranged to lift the gripping deck (13) together with the casing (2). A method of loosening and pulling a casing (2) with said derrick assembly (1) is described as well. |
