Borehole Geometry

The 4-Arm Dipmeter measures microresistivity and tool orientation data.

These can be processed to determine formation dips.

Principle of Measurement:

The probe consists of a microresistivity section and a detachable verticality module. Microresistivity data is acquired by four highresolution, button electrodes mounted on motorised XY caliper arms and maintained in contact with the borehole walls. A planar formation feature that does not lie perpendicular to the borehole axis is detected by each electrode at a different apparent depth.

The four microresistivity measurements are correlated and combined with the verticality data to calculate the dip and dip direction.

Specification : 

Features

Small diameter for slim-hole operations

Operates in all orientations

Measurements

Formation dip and azimuth

Microresistivity

Borehole verticality and drift

True vertical depth

Borehole volume

Natural Gamma

Applications

Engineering/minerals

Stratigraphy

Sedimentology

Identification of faults and folding

Fracture identification

Correlation between wells

Operating Conditions

Borehole type  :  open, water-filled

Centralisation  :  non-magnetic centralisers required for inclined

boreholes and/or diameters above 150mm

Recommended Logging Speed  :  3m/min

Specifications

Diameter  :  61mm (when closed 66mm)

Length  :  5.17m

Weight  :  52kg (combined)

Temperature  :  0-70⁰C (extended ranges available)

Max. pressure  :  20MPa

Resistivity range  :  1 to 10,000 ohm-m

Borehole inclination  :  any

Caliper range  :  62-380mm

Part Numbers

I002171    4-Arm Dipmeter probe with natural gamma