Abstract
Abstract This study examines the use of fiber-optic sensors for real-time monitoring of pressure and temperature in oil and gas wells. Unlike electronic sensors, which often fail under extreme downhole conditions, fiber-optic systems provide high accuracy, resistance to electromagnetic interference, and long operational lifetimes. The work proposes a hybrid architecture that integrates Fiber Bragg Grating point sensors with Brillouin-based distributed sensing, enabling both localized calibration and continuous profiling along the entire wellbore. This configuration allows independent retrieval of temperature and pressure by simultaneously analyzing wavelength and frequency shifts. Numerical modeling and laboratory experiments were conducted under pressures up to 100 MPa and temperatures up to 200 °C. The hybrid system demonstrated high stability, with deviations between simulated and measured values not exceeding a few percent for both temperature and pressure. Long-term testing confirmed reliable operation and minimal drift over 500 hours of cyclic loading. The results indicate that the proposed sensing configuration ensures high-fidelity real-time monitoring and is suitable for integration into Industry 4.0 smart-field platforms, enabling predictive diagnostics and improved operational safety in oil and gas production.