| 摘要 |
1,066,774. Boring earth &c. INSTITUT FRANCAIS DU PETROLE, DES CARBURANTS ET LUBRIFIANTS. July 23, 1963 [July 24, 1962], No. 29180/63. Heading E1F. A sub-aqueous well is drilled by means of a drilling head carried by a flexible: tubing, a substantially constant force being applied at a point B to a lower preselected length of tubing and the weight of the upper part of the tubing being supported from the drilling station N. The constant force is applied by a float E which sinks as drilling proceeds and as tubing is lowered intermittently or continuously from the station. To prevent crushing of the float the cable connecting it to the point may be extended as drilling proceeds or the float may be flexible and filled with a fluid. The lengths of the lower preselected length of tubing may be fixed, or may be adjusted continuously or intermittently as drilling proceeds.
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