Fiber Optic Sensor Based Monitoring System for Blowout Preventer

Abstract

Ultra-deep water BOP (Blowout Preventer) operation poses numerous challenges in obtaining accurate knowledge of current system integrity and component condition-a salient example is the difficulty of verifying closure of the pipe and shearing rams during and after well control events. Ascertaining the integrity of these functions is currently based on a manual volume measurement performed with a stop watch. Advances in sensor technology now permit more accurate methods of BOP condition monitoring. Fiber optic sensing technology and particularly fiber optic strain gauges have evolved to a point where we can derive a good representation of what is happening inside a BOP by installing sensors on the outside shell. Function signatures can be baselined to establish thresholds that indicate successful function activation. Based on this knowledge base, signal variation over time can then be utilized to assess degradation of these functions and subsequent failure to function. Monitoring the BOP from the outside has the advantage of gathering data through a system that can be interfaced with risk based integrity management software and/or a smart monitoring system that analyzes BOP control redundancies without the requirement of interfacing with OEM control systems. The paper will present the results of ongoing work on a fully instrumented 13-½" 10,000 psi pipe ram. Instrumentation includes commonly used pressure transducers, accelerometers, flow meters, and optical strain gauges. Correlation will be presented between flow, pressure, acceleration signatures and the fiber optic strain gauge's response as it relates to functional verification and component level degradation trending.

Research on Measurement and Prediction of Well Blowout Fluid Flow Rate based on Machine Vision

“…E. Hajidavalloo installed flow tubing at the wellhead and varied the size of the tubing to study its effect on the blowout flow rate [15]. A. Turner and P. Loustau use blowout preventers for blowout-related parameter measurements, which are fast and work consistently in complex environments [16]. M. D. Dunn predicted the blowout fluid flow velocity under freefield conditions and concluded that the jet velocity decreases with increasing jet height as the natural entrainment generated by air flows radially into the jet [17].…”