Abstract: This invention concerns the production of very deep boreholes. A rotary drilling tool is suspended at one end of a very long line of supporting elements such as a cable. During at least the entire duration of the drilling operation, the borehole is filled at least partly with at least one substance which remains in a liquid state and has a density greater than the mean density of the drilled ground strata. Thus any infiltrations in the borehole and the drilling debris move naturally upwards to the free surface of the liquid substance filling the borehole.
Type:
Grant
Filed:
May 24, 1978
Date of Patent:
January 29, 1980
Assignee:
Coyne & Bellier, Bureau d' ingenieurs Conseils
Abstract: This invention concerns the production of very deep boreholes. A rotary drilling tool is suspended at one end of a very long line of supporting elements such as a cable. During at least the entire duration of the drilling operation, the borehole is filled at least partly with at least one substance which remains in a liquid state and has a density greater than the mean density of the drilled ground strata. Thus any infiltrations in the borehole and the drilling debris move naturally upwards to the free surface of the liquid substance filling the borehole.
Type:
Grant
Filed:
December 10, 1976
Date of Patent:
September 26, 1978
Assignee:
Coyne & Bellier, Bureau d'ingenieurs Conseils