Distributed Fiber Optic Sensing – A Technology Review for Upstream Oil and Gas Applications

Real-time downhole measurement is essential for monitoring and optimizing well performance. For advanced wells, this enables zonal flow evaluation which leads to production control adjustments and ultimately closed loop optimization. The challenge is to turn these real-time measurements into real-time decisions for effective reservoir and production management. Optical fibers provides a great opportunity to achieve this in an economic and safe manner. This is because fiber optics is a non-intrusive tool that has the ability to detect acoustic and thermal effects anywhere along the well with very high frequency sampling both in terms of space and time. The paper will establish the basic understanding of distributed measurement principles. Then, it will cover the different installation methods based on the parameter of interest. The fiber deployment can occur during initial well construction, or after completing the well as an intervention. The remainder of the paper focuses on different possible application of Distributed Acoustic and Temperature Sensing (DAS and DTS) that strive to solve day-to-day oil field challenges. The task of using real-time fiber optics measurements to monitor well performance is very complex and requires involvement from several disciplines within an organization. To illustrate the complexity of this task, we discuss the application of using distributed measurements for production and injection profiling as an example. An overview of algorithms commonly used to interpret flow from DAS and DTS measurements is presented. Furthermore, the use of DAS and DTS for sand detection and wellbore integrity applications is explained. Each application is supported with examples with the aim to provide reservoir and production engineers guidance to identify appropriate solutions for their challenges.