| 摘要 |
Apparatus for performing rotary or cutting operations in a subterranean borehole or conduit, particularly sealing operations, comprises a downhole assembly connected to a cable (6). The downhole assembly comprising at least one of a rotary tool (18, 19, 21) coupled to an electric motor or fluid motor (39), a rotary tool (22, 23, 24, 161, 180) coupled to a fluid motor (39), or an axial cutting tool (20) coupled to a piston. The fluid motor or piston (64) is operated by differential fluid pressure created within the bore. Methods of sealing a subterranean borehole are also provided, in which one or more cuts (170, 170A/170B, 170C) are made with a cutting assembly in one or more conduits (96, 98, 101, 103, 144, 145, 167, 168, 177) to remove at least a portion of a conduit and concrete is deposited in the resulting space. The space is free of debris which could otherwise form leakage paths in the concrete seal. In a variant the space is created with a downhole crushing apparatus (18, 19). |
