Distributed Temperature Sensor (DTS) System Modeling and Application

Abstract

Abstract Distributed Temperature Sensor (DTS) technology uses fiber-optic cable to measure a continuous temperature profile along the wellbore. Compared to conventional production logging tools (PLT), DTS can provide operators real-time well information without intervention. Applications, from flow profiling to gas lift surveillance, have grown steadily in recently years. DTS applications require reliable data modeling and analysis or measurement interpretation. The complexity of the data analysis has been a barrier to DTS usage. This paper presents software tools developed for DTS interpretation. The model behind the software is based on steady-state energy balance, and it is applicable for gas and oil wells in both onshore and offshore environments. The software allows users to run in two modes: forward simulation and flow profiling. The forward simulation mode calculates the temperature distribution along the wellbore for any given production profile, and this mode is critical for the model calibration. It is also very useful for emulating "what-if" scenarios, such as forecast and gas lift surveillance. The flow profiling estimates the production profile based on measured temperatures, which is the basis for the real-time well monitoring. The model is tested against other models and good agreement has been obtained. This paper presents two examples: result comparison against TIPP, a computer program package developed by Chevron Corp, and a field example to verify gas lift valve operation.