BOREHOLE LOGGING APPARATUS FOR DEEP WELL DRILLINGS WITH A DEVICE FOR TRANSMITTING BOREHOLE MEASUREMENT DATA

摘要

In a borehole logging apparatus (1) for deep well drill- ings having a device for transmitting measured data obtained while drilling from a borehole through the drilling fluid to the earth's surface, there is arranged in the upper end of a housing (2) a signal transmitter (13) comprising a beaker- shaped rotor (24) and a stator sleeve (25) surrounding said rotor. Fluid impinges on the signal transmitter (13) through a central feed pipe (15) surrounded by an exchangeable bypass ring (14) to which the complete current of drilling fluid is routed through a filter pipe (3) and through which part of the drilling fluid current is routed back into the drill string (6). From a set of bypass rings (14) of different by- pass cross sections it is possible to select one suited for the particular on-site conditions and insert it into the logging apparatus (1) in order to obtain a significant signal through the signal transmitter (13).