Qualification of Spool Deployed Fiber Optic Gauge Array for Sand-Face Monitoring

Abstract Intelligent Completion technology benefits from integrating permanent downhole monitoring systems. Current Inflow Control Devices (ICDs) lack real-time monitoring of annulus and tubing pressures. A new global first spool-able fiber optic gauge system was developed and tested that provides cost-effective, continuous multi-point pressure-temperature monitoring at the sandface. This enables real-time well management, including zone identification, leak detection, and optimization of production efficiency. It also facilitates estimating flow rates from individual compartments, improving overall reservoir management. To identify potential failure modes of the system, Vibration, shock, and drop tests were conducted on a spool-able fiber optic gauge system to identify potential failure modes. The goal was to expose the device to extreme environmental conditions beyond what it would encounter during normal use or transportation. By doing so, any inherent weaknesses should become apparent faster, allowing for quicker identification of potential issues. The tests aimed to detect both operational failures (compromised gauge function) and destructive failures (total loss of function or physical damage). This helps ensure the reliability and durability of the gauge system and its components. The gauge systems were subjected to vibration, shock, and drop tests at operating temperatures to identify potential operational and destructive failure modes. Resonance frequency sweeps indicated no significant resonance frequencies within the jig assembly. Long-term random frequency vibration tests conducted over two weeks did not reveal any potential failure modes, and the performance of both the temperature compensation sensor and the pressure sensor remained uncompromised. Additionally, vibration and shock tests at operating temperatures were performed. No discontinuities in Fiber Bragg Grating (FBG) wavelength were observed during these tests, and sensor functionality was consistently maintained without any apparent failure modes. Drop testing also did not indicate any failure modes in the gauge sensor assembly. Following bench testing and qualification, the system was deployed in a test well to demonstrate that the spool-able array could be installed, and that the system accurately reflects real well conditions. A novel spool-able type of monitoring system uses Bragg-Grating fiber optics to track pressure and temperature changes in oil wells. This system could make it cheaper and easier to monitor wells in real time, reducing the need for expensive logging tools. With accurate readings, we can estimate how much fluid is being produced, making operations more efficient and saving money. Overall, this innovation could lead to big cost savings and fewer disruptions to production activities.