主动加热测温分布式光纤布里渊海底管道冲刷悬空监测与评定

Suspension scour of subsea pipeline is one of the most important problem which leads to integrity deterioration and huge loss. However, it is quite difficult to utilize current monitoring or inspection techniques to monitor the subsea pipeline suspension in real time for long term, because of their shortages, such as difficult installation, high cost, local monitoring, etc. Aiming at this problem, advantages of fiber optical Brillouin sensing technique, such as high durability, distributing monitoring ability, are considered and utilized in this proposal. And then, one novel kind of scour monitoring method base on active thermometry and fiber optical Brillouin sensing technique is proposed from the new point of view. Suspension scour length is monitored by means of heat conduction difference detection between water and sand sediment exposure of subsea pipeline. Theoretical analysis, model test, Numerical Simulation and big scale model test are used in the research work in this proposal. Firstly, scour length sensing technique and sensors will be studied and developed. Sensor packaging structure parameters optimization, sensor packaging method and temperature sensitiviy will be studied. Secondly, scour evaluation method will be established. Active thermometry temperatue reaction feature extraction, noise recognition and reduction, Support vector machine based evaluation method and two-dimension scour evaluation method will be researched. And then, one subsea pipeline scour length monitoring and evaluation system will be integrated and established. Furthermore, key engineering techniques are also researched for field application in the future. Finally, one test benchmark system will be developed for invalidation of all the research works in this proposal. The research of this proposal will provide scientific support for safe operation of large-scale subsea pipeline engineering infrastructure.

冲刷悬空是引起海底管道完整性降低并造成巨大损失的重要影响因素。目前的海管冲刷监测、检测技术，由于受到布设难度大、局部测量等瓶颈的制约，难以满足对长距离海管线性结构的分布式监测需求。为克服上述瓶颈，解决这一难题，申请人在国内外第一次提出一种基于主动加热测温法与光纤布里渊温度传感技术的新型分布式监测方法，从海管冲刷前后外部海水与泥沙介质的热传导性能差异探测这一崭新角度实现冲刷长度监测。首先，研制主动加热分布式海管悬空传感器，开展封装结构参数优化、封装工艺、传感特性研究；然后，建立海管冲刷长度评定方法，开展典型海床主动加热温度分布特征提取、噪声识别与降噪、基于支持向量机海管悬空评定与二维海管悬空评估研究；之后，集成海管冲刷长度监测评定系统。发展海管冲刷悬空监测工程化关键技术；最后，建立综合试验验证平台对本项目研究成果进行长期综合验证，为保证我国大规模海底管道工程基础设施的安全运营提供科学支撑。

冲刷悬空是引起海底管道完整性降低并造成重大损失的重要影响因素之一，针对这一难题，目前的海管冲刷监测、检测技术，由于受到布设难度大、局部测量等瓶颈的制约，难以满足对长距离海管线性结构的分布式监测需求。为克服上述瓶颈，解决这一难题，申请人在国内外第一次提出一种基于主动加热测量法与光纤布里渊温度传感技术的新型分布式监测方法，从海管冲刷前后外部海水与泥沙介质的热传导性能差异探测这一崭新角度实现冲刷长度监测。.本项目充分利用DS18B20温度传感器分布式测量等优点，国内外首次提出一种基于主动加热原理的海管悬空长度监测方法，从海管冲刷前后海水与泥沙热传导性能差异进行探测，这一崭新角度实现冲刷长度监测。研究新型海管悬空长度监测传感技术及传感器，研究悬空长度评估方法实现对海管长期冲刷状态监测与评估，发展海管冲刷悬空监测工程化关键技术，研究冲刷悬空监测系统集成技术，建立海管冲刷悬空长度监测与评估系统，为保证我国大规模海底管道工程基础设施的安全运营提供科学支撑。同时本研究提出一种基于低成本拉曼传感技术的新型分布式监测方法，并首次引入普通铠装光缆，应用光缆内部的金属线作为主动加热单元，光纤作为温度传感单元，大大提高了传感器的整体性能。此外，铠装光缆封装牢固，应用广泛，安装便捷，为现场布设提供了极大地便利性。