Disposable Intervention Tool for Production Logging

Abstract

Abstract Fiber optics can be readily introduced into wells to gather data at very low cost by using a novel, disposable deployment method called FiberLine Intervention (FLI). To date, FLI technology has been used to cost-effectively install bare optical fiber in wellbores to collect distributed sensing data, such as distributed temperature sensing (DTS) and distributed acoustic sensing (DAS). In this ‘passive’ sensing mode a variety of applications have been demonstrated, for example, cement assurance, leak detection, injection monitoring and vertical seismic profiling. The FLI technology has now been expanded to include "active" elements which provide additional, discrete, electronic sensing functions from within the deployed probe. This capability enables the combination of single point data with distributed sensing information to provide enhanced well intelligence and assist with a wider variety of production logging applications, including evaluating well and reservoir performance and completion effectiveness. To deploy FLI, the probe is configured on the wellhead in a small, pressure containing launcher. This releases the probe which free-falls downhole laying the fiber into the well. Following the development of "Active FLI", the probe can now be configured to house a suite of low cost, expendable electronic sensors such as a pressure gauge, a temperature sensor and a casing collar locator (CCL). The fiber transmits the digitized sensor data - in real time - to a miniature surface data acquisition system. Following completion of sensing and monitoring operations, which typically last several hours to a few days, the probe and fiber are then disposed of in the well. The active electronic sensors collect data during the probe's descent into the well and can continue with ongoing monitoring when the tool reaches its final depth. The sensors can be deactivated on demand and the same fiber can then be utilized for distributed sensing. Alternatively, two fibers can be deployed allowing for the simultaneous collection of single-point data and ongoing distributed sensing throughout the wellbore. Active FLI technology will be described in this paper and data from a representative field trial will be presented. The solution remains disposable, thereby resulting in a low cost, low risk and minimal impact method for obtaining key wellbore information during shut in, production and injection operations.