Capacitance - Temperature - Flow Tool


Measures capacitance water holdup, downhole temperature, and flow in a single compact tool


  • Profiling injection and production flow
  • Detecting leaks, crossflow, fluid entry, and fluid movement behind pipe
  • Profiling two-phase production
  • Calculating water holdup
  • Performing qualitative analysis of high gas-to-oil-ratio wells

Features and Benefits

  • Three sensors in a short section of the tool obtain data typically obtained by individual sensors deployed on a standard tool string.
  • The compact tool body reduces the total tool-string length, which is especially valuable in applications with limited rig space, such as offshore operations.
  • The platinum-resistance temperature probe responds quickly and accurately to changes in fluid temperature.
  • The capacitance/temperature/flow (CTF) tool obtains precise measurements by minimizing the watering-out effect that can result in the tool continuing to read water even after hydrocarbons have replaced the surrounding fluid.
  • The tool mitigates the effects of salinity, which helps to avoid corrections and post-processing calculations.
  • The tool offers enhanced measurement capabilities in wells with water holdup values greater than 50 percent.
  • The tool operates in a wide range of downhole conditions, and it can be combined with other Ultrawire™ tools to enable simultaneous measurements and increased operational efficiency.

Tool Description

The CTF tool combines three sensors in a single, short electronics section. This design enables measurement of capacitance water holdup, downhole temperature, and flow from the same well depth.

To measure capacitance water holdup, the CTF tool identifies fluids based on the difference in dielectric constants between hydrocarbons and water. As fluid passes between the cage of the tool and an inner probe, the output frequency responds to the average dielectric constant of the fluid. From this response, the downhole water-hydrocarbon ratio can be determined.