Resistivity imaging devices

Class of borehole imaging tools that works on the principal of varying formation resistivity.  Electrodes make resistivity measurements of the borehole wall as function of depth and orientation; these resistivity determinations are processed to form an oriented resistivity map of the borehole wall.  Resistivity imaging tools fall into three categories.  Multi-arm pad devices with tight arrays of microresitivity buttons; rotating electrodes fitted to a drill-collar and laterolog sensors arranged circumferentially.  Most resistivy imaging devices require a conductive mud environment, but technological developments allow some newer tool types to function in oil-based fluids.

 

LUTHI, S. M.  2000.  Geological Well Logs.  Springer, Berlin, p373.

 

PRENSKY, S. E. 1999.  Advances in borehole imaging technology and applications.  In: LOVELL, M. A., WILLIAMSON, G and HARVEY, P. K. (eds.).  Borehole Imaging: Applications and Case Histories.  Geological Society Special Publication No. 159, 1-43.

 

See also borehole televiewers and density and photoelectric effect imaging devices.

 

 

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