# Photoelectric Composite Three-Phase Flow Sensor for Complex Oil and Gas Wells

## TL;DR

A new sensor for oil and gas wells combines electrical and optical methods to accurately measure complex three-phase flows.

## Contribution

A novel photoelectric composite sensor is developed for high-precision three-phase flow measurement in oil and gas wells.

## Key findings

- The sensor accurately measures gas holdup and phase velocities with high sensitivity to bubble-flow structures.
- It achieves stable water holdup calibration from 0% to 100% with effective temperature and salinity compensation.
- The sensor offers higher integration and resolution compared to existing technologies, especially in low-saturation areas.

## Abstract

Reliable measurement of multiphase flow is fundamental to production evaluation in complex oil and gas wells. However, conventional sensors often suffer from low integration, limited measurement capability, and potential environmental impact. To address these challenges, a photoelectric composite three-phase flow sensor is developed, integrating multiple electrode rings for water holdup and liquid-phase velocity measurement, with dual optical-fiber probes for gas holdup and gas-phase velocity detection. A slip model is further applied to quantify the dependence of slip velocity on liquid holdup based on measured phase rates. Experimental results demonstrate high sensitivity to bubble-flow structures, accurate extraction of gas holdup and phase velocities, and stable full-range water holdup calibration from 0% to 100% at 5 V and 15 V with effective temperature and salinity compensation. And compared with existing technologies, the sensor designed in this paper has the advantages of high integration, a simple structure, multiple measurement parameters, and higher water-holding capacity resolution in low-saturation areas, providing more advanced technical means for conventional profile three-phase flow logging.