The Micro Spherical tool provides a resistivity measurement in the invaded zone. This is useful in distinguishing moveable hydrocarbons. When used in combination with a deep and medium reading resistivity tool, the MST can help estimate Rt (Resistivity of the Virgin Zone). This tool also records a MicroLog with the appropriate pad attached to the backup arm. The MicroLog provides two shallow Depth-of-Investigation (DOI) resistivity values. At 1 inch DOI, the shallower INV is mostly influenced by mud cake. Normal (NOR) at 4 inches DOI is influenced by the flushed formation making this an excellent permeability indicator device.
|Pressure||20,000 PSI||1,379 bar|
|Temperature||325° F||163° C|
|Weight||200 lbs||90.72 kg|
|Tool Length||9.66 ft||2.94 m|
|Transport Length*||11.47 ft||3.50 m|
|Tool OD (MSFL Pad)||5.25 in||13.3 cm|
|Max. OD (MSFL/Micro pads)||5.75 in||14.6 cm|
|Tool OD (Micro pad)||4.50 in||11.4 cm|
* From end of top thread protector to end of bottom thread protector.
|MSFL||2 in||2.54 cm|
|Depth of Investigation|
|MSFL||4 in||10.2 cm|
|MSFL||0.2 – 2000 Ω-m|
|Caliper||4.5 – 18 in||11.4 – 45.72 cm|
|Maximum Logging Speed||45 ft/Min||13.7 m/Min|
|MSFL||±5% 0.2-200W-m, ±10% 200-2000W-m|
|Caliper||±0.2 in||±5.1 mm|
|Minimum||6.0 in||15.2 cm|
|Maximum||22 in||55.8 cm|
Open hole, fluid filled.
The MST cannot be run in non-conductive fluids such as oil-based muds or air-filled holes.