Critical Analysis and Application of Optical Fiber Sensors in Oil and Gas Industry . Arsalan Ahmeda Godio Albertob a(MSc Petroleum Engieering, DIATI, Politecnico di Torino) b(Supervisor, Associate Professor, DIATI ,Politecnico di Torino) Abstract Optical fiber sensors application in oil and gas industry both in upstream and downstream sector have very importance from measurement of temperature, pressure to vibration. Some of the most prominent examples, and its usage: in seismic measurement causes by Hydraulic Fracturing. And the usage of optical fiber in oil and gas industry apart from measuring seismicity is very prominent and already in practice like Haliburton 1 (FiberPoint) which is the pressure gauge provide reliable point pressure at temperature results up to 300C.