Temperature is one of the most fundamental and essential measurements in the oil and other process industries, vital for both safety and efficiency of operations. To monitor and control upstream oil and gas processes, operators need robust and reliable temperature measurement.
In wellhead applications, the mixture of oil, water, and gas flowing at high speed makes the use of conventional invasive thermowell measurements difficult. Given the importance of temperature, operators resort to using clamp-on temperature transmitters to measure pipe temperature as a proxy for process temperature. However, under the challenging ambient conditions at offshore locations these measurements can be subject to unpredictable errors.
A comprehensive study and evaluation by Equinor on their Johan Sverdrup oil platform highlighted the extent of these errors in typical applications. Comparisons between invasive and conventional clamp-on temperature measurements showed that the latter is affected by factors such as wind speed, the amount and type of thermal insulation, and the design of the clamp-on sensor.
This resulted in deviations of up to 10°C with typical process temperatures of 65°C.