Down Hole Enthalpy Measurement

Abstract

A project investigating ways to measure enthalpy down hole, either by constructing a device specifically for that purpose or expanding the use of existing measurement technologies is now underway at Stanford University. So far three different methods have been investigated in an effort to sense flow rates and void fraction in segmented air-water flow. The three sensors being considered are a thermocouple, a resistivity electrode and a photo sensor. So far the thermocouple measurements have not proven successful but the resistivity and photosensors have shown good response. Thus far a method has been devised to determine the air and water flow rates (assuming no slip) and void fraction in this given segmented flow case.

Current research efforts are in measurement of the same properties in dispersed bubble flow. These measurements are being done using the well bore modeling tube that has been built at the Stanford Geothermal Lab. So far the velocity estimation is looking good but the void fraction probably requires more sensors for an accurate estimate.