Chemical marker injection

{
  "id": "MLC-T-OAG-000649",
  "term": "Chemical marker injection",
  "field": "Oil and gas",
  "definitions": [
    "A production logging technique for measuring fluid velocity and identifying flow paths by injecting a small volume of a distinct, detectable chemical into the wellbore stream. Sensors positioned along the tool string or at different well depths record the marker's arrival time and concentration as it moves with the produced fluids. The velocity is calculated from the transit time between two detectors, and this method can also locate leaks behind casing or in tubing.",
    "A production logging method for determining fluid velocity and diagnosing flow problems by introducing a small quantity of a unique chemical tracer into the production flow. Detectors placed at known distances apart record the passage of this tracer, and the time difference is used to calculate the speed of the fluid phase carrying it. This technique is distinct from radioactive tracer injection, which uses a gamma-ray emitting isotope instead of a chemical compound."
  ],
  "subject": "Production Logging",
  "url": "https://mlchart.com/terminology/oil-and-gas/chemical-marker-injection/"
}