Spec Sheet:

Cased-Hole Logging

Resistance Array Tool

Resistance Array Tool (RAT)

Production logging in horizontal wells

The Resistance Array Tool (RAT) is a 12-sensor fluid identification tool determining water hold-up across the wellbore. Water is conductive, whereas hydrocarbons (oil and gas) are nonconductive. Each sensor measures the resistance of the fluid between probes at their tips.


Key Features

  • Differentiates between water and hydrocarbons
  • Cross-sectional water hold-up profile
  • Identification of water entry points
  • Water hold-up profile in any fluid regime
  • Can detect very small and fast moving bubbles
  • Independent of well deviation
  • Internal orientation sensor
  • Combinable with other GE Ultrawire™ tools
  • Memory or surface read-out operation

Technical Information

Service NameRAT
Length1310 mm / 51.4 in
Weight8.2 kg / 18.0 lbs
OD43 mm / 1.688 in
Maximum opening7 in casing
Maximum pressure1030 bar / 15 000 psi

Maximum temperature

177 °C / 350 °F


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