To reduce the surveying error in a wellbore, the creation of several reference points within a borehole is carried out by physically placing borehole markers in the borehole casing, the borehole wall or in the formation itself, and providing an accurate reference of the marker locations by either storing information specific to the borehole markers inside or on the marker itself, or assigning an identification number to the marker and storing the information relating to that identification number remotely in a database. The borehole markers may contain an electronic module which includes a microcircuit, a transponder dedicated to the transmission and reception of data to/from a detector placed on a wireline tool, a drill string or a coiled tubing. The detectors may have an additional role of interrogating the electronic modules.

 
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> Canted universal elastic polymer holster hanger with indistinguishable belt lock and flex arm to conceal holster, to produce shirt-engaging flex cam surface, and to produce flexed gun securing surface

~ 00340