Intelligent well completions enable production and/or injection to be controlled and optimized across multilateral reservoir zones. The Distributed Acoustic sensor (DAS) is a promising technology for a number of wellbore monitoring applications such as distributed flow profiling. The DAS system can provide real-time monitoring across several zones equipped with Inflow Control Valves (ICVs) and Inflow Control Devices (ICDs) that are used to optimize the production and extend the life of the reservoir.
The new intelligent Distributed Acoustic Sensor (iDAS) uniquely allows the simultaneous recording of acoustic energy along many kilometers of optical fiber deployed along the wellbore. The system uses a novel digital optoelectronics detection technique that captures the amplitude and phase of the acoustic waves generated and propagated along the wellbore over a wide frequency (8mHz – 100kHz) range with a high dynamic range (>120dB). A number of signal processing techniques have been developed for processing a large array of acoustic data that can be recorded along the wellbore for monitoring the inflow at different zones.
There are a number of intelligent well completions with fiber optic cable installations in Saudi Arabia. The DAS system described here can be retrofitted to the existing installations both with the multimode fibers, which were originally installed for the Distributed Temperature Sensor (DTS), and with single-mode fibers that are used for telemetry to point optical sensors.
The paper will report on the first survey results of the DAS measurement in an intelligent well that is equipped with ICVs. The results will show how the DAS system can be used to monitor the completion components such as by listening to the inflow noise across ICVs and ICDs and indicate the inflow contributions from different zones. The paper will present the first DAS survey using multimode fibers that was installed for the DTS measurements.