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Application filed by Dale ParkerfiledCriticalDale Parker
Priority claimed from PCT/AU2015/000276external-prioritypatent/WO2015172179A1/en
Publication of MY184746ApublicationCriticalpatent/MY184746A/en
A survey tool (1) for attachment to a drill string (108) for inserting the survey tool into a borehole, the survey tool comprising a housing having a proximal end adapted for attachment to the drill string and a bore traversing the housing adapted to receive fluid from the drill string, and a piston (20,80, 129, 109) adapted to be received within the bore, the piston being adapted to be selectively displaced between at least a first condition and a second condition, wherein in the first condition the fluid exists the housing at a first location and in the second condition the fluid exists the housing at a second location. (Figure 1)