| Deployment | Borehole | ||
|---|---|---|---|
| Log Name | HEX | ||
| Math Symbol | \delta T_{\rm hex} | ||
| Model | Fluid flow velocity along the tool | ||
| Sensor Type | Thermoanemometer | ||
| Units | SI | Oil Metric | Oil Field |
| °C | °C | °F = 9/5 T [°C] + 32 |
Applications
- Assesing donwhole flowrate
Sample Logs
Tool Schematic
One sensor is measuring the intake fluid temperature.
The other sensors is heated with constant power.
The difference between heated and unheated temperature sensors depends on fluid velocity and fluid type:
| HEX = T_{\rm heated} - T_{\rm intake} |
Mathematical Model
| H_{exf} = S_{\rm slope} \cdot ( v - v_{th}) |
where S_{\rm slope} is some constant depending on tool construction and well completion , v_{th} a critical value of the flow speed which can initiate spinner rotation, v – flow velocity.