Resistance Array Tool


Determines the cross-sectional water-holdup profile in wellbores of any deviation and in any flow regime


  • Water-holdup measurement in deviated or horizontal wellbores
  • Identification and mapping of multiphase fluid segregation

Features and Benefits

  • Cross-sectional water-holdup profiling provides a radial fluid-phase measurement to build a more complete fluid profile in deviated wells.
  • Distribution of sensors around the circumference of the the resistance array tool (RAT) provides a complete cross-sectional profile of fluid distribution for building an accurate flow profile.
  • Memory and surface readout operations allow running the toolstring on a variety of conveyance platforms, which enables deployment using the most costeffective method.
  • The RAT can operate simultaneously with Sondex™ and Ultrawire™ tools that measure other aspects of the flow stream, such as fluid makeup, to ensure that all measurements are obtained at the same moment for more reliable data.

Tool Description

The RAT has 12 microresistance sensors that are deployed on bow springs and used to determine the water-holdup profile across the complete wellbore. The RAT differentiates between conductive water (brines) and hydrocarbons (which are nonconductive) and detects very small, fast-moving bubbles. This enables operators to determine the cross-sectional water-holdup profile in wellbores of any deviation, from vertical to horizontal, and in any flow regime.

Combined with the spinner array tool (SAT) and capacitance array tool (CAT), the RAT delivers precise quantitative estimations of the volumetric flow rate for each phase. With more accurate flow-rate data, operators can make better reservoirmanagement decisions.