Design and simulation of a novel multi-diaphragm cable for distributed pressure sensing in oil and gas applications

This paper introduces the design framework and corresponding simulation-based validation of a novel fiber-optic distributed pressure sensing (DPS) cable developed for real-time pressure monitoring in harsh downhole environments. The cable employs a square-shaped structure that optimizes diaphragm flatness, enhancing fabrication feasibility and measurement consistency. A single optical fiber runs through multiple pressure locations, with specific segments stretching in response to diaphragm deformation, achieving a pressure sensitivity of 1.7 µstrain/MPa over pressures up to 137.9 MPa. A second fiber, dedicated to temperature compensation, passes through the same region while remaining decoupled from diaphragm deformation, ensuring accurate pressure readings with a temperature sensitivity of 7.6 µstrain/°C. Although the achieved sensitivity is moderate compared with discrete FBG or Fabry–Perot sensors, it remains appropriate when considering the wider pressure range, structural robustness, and distributed configuration. The proposed cable establishes the foundation for assessing accuracy, resolution, and noise in future prototype validation. Designed as a multisensory platform, it can incorporate Distributed Acoustic, Strain, and Temperature Sensing while maintaining parameter decoupling offering a scalable solution for distributed pressure monitoring in energy and geophysical applications.