Radiotracer method for residence time distribution study in multiphase flow system.

Area of Science:

• Multiphase flow dynamics in hydrocarbon transmission pipelines.
• Radiotracer technology for fluid flow measurement.
• Chemical engineering and process monitoring.

Background:

• Hydrocarbon pipelines often transport multiphase fluids, including water, oil, and gas.
• Accurate flow rate measurement is crucial for pipeline operation and efficiency.
• Understanding the distinct flow behaviors of different phases is essential.

Purpose of the Study:

• To measure and compare the flow rates of water and crude oil in a multiphase pipeline.
• To investigate the reasons behind observed differences in phase velocities.
• To characterize the flow patterns within the pipeline system.

Main Methods:

• Injection of radiotracers: sodium iodide ([131]I)Na into water and iodobenzene ([131]I)C6H5 into crude oil.
• Utilizing two scintillation detectors placed at 80m and 100m from the injection point.
• Analysis of residence time distribution data to calculate phase flow rates.
• Calculation of Reynolds number to determine flow patterns.

Main Results:

• Water consistently flowed faster than crude oil, contrary to expectations based on density.
• The water-dominated system and interphase friction likely cause crude oil to move slower.
• Water flow was characterized as turbulent based on Reynolds number calculations.

Conclusions:

• Radiotracer measurements provide valuable insights into multiphase flow behavior in pipelines.
• Water acts as a carrier fluid, influencing the slower movement of crude oil.
• The findings explain why crude oil is often detected after water at gathering stations.