Conditions inside an oil well are pretty intense with temperatures from 120°C–300°C and pressures to several thousand psi. However, monitoring the temperature inside the well is important to understand and control well behavior to achieve the best yield.
THE CHALLENGE Monitor temperature along the entire length of an oil well
A major oil manufacturer uses Agilent's distributed temperature sensing (DTS) system in their oil wells. The system links a sheathed fiber-optic cable to an optical read-out unit, which can be placed outdoors, next to the well, powered by a solar panel. The temperature measurements from the optical fiber allow you to correlate the known geothermal gradient with the mea-sured temperature and known well flow to identify which portions of the well are producing and which are experiencing diminishing flow.
Two-thirds of the world's oil is so-called heavy oil and to get this stuff moving up and out, steam is injected. Sometimes water can break through the strata around the well and cause localized cooling, at which point the oil can get stuck. Monitoring temperature along the entire length of the well allows you to spot when a breakthrough happens and take corrective measures.