Method and apparatus for surveying the direction and inclination of a borehole
FR1531767A
Method and device for recording temperatures during drilling
GB1170487A
Fluid Temperature Logging While Drilling
US3381215A
Measurement of electrical resistivity by variation of magnetic flux
US3374669A
Drilling rate logger
US3377549A
Coil assembly structure and mounting forming an annular chamber to be mounted and sealed on a drill collar
US3345867A
Method and apparatus for measuring rock bit wear while drilling
FR1408977A
Measurement of the resistivity of formations during drilling
US3327527A
Fluid temperature logging while drilling
IE27348L
Snow blower.
US3264763A
Snow blowers
US3305771A
Inductive resistivity guard logging apparatus including toroidal coils mounted on a conductive stem
US3408561A
Formation resistivity measurement while drilling, utilizing physical conditions representative of the signals from a toroidal coil located adjacent the drilling bit
US3115942A
Method of earth borehole in vestigation
FR1420251A
Method and apparatus for measuring the wear of a rock drill bit during drilling
