油气井多相流核磁共振在线检测新装置与新方法研究

Rapid quantitative detection of multiphase flow in oil & gas wells and pipelines is one of the common problems faced by the oil & gas industry of the world, with great potential. The accurate measurement of high water content and gas production fluid has been the direction of academic and industrial circles. In order to solve this problem, the existing instruments must be divided the multiphase fluid into three phases: oil, gas & water, and the problems such as narrow measurement range, large error, poor anti-interference ability, complex process and so on. This project is aimed at the difficult problem on the quantitative detection of multiphase flow in oil & gas wells and pipeline, proposing an innovation for online nuclear magnetic resonance detection (NMR), exploring the following 3 key issues: "Magnetization efficiency and signal loss rate control in flow state", "Fast acquisition of NMR signal and pulse sequence" and "Data processing and quantitative interpretation of multiphase flow online detection". Then, verified the experimental results by a prototype to obtain a novel rapid online technique for quantitative detection of multiphase flow in oil & gas wells and pipelines. NMR is an efficient and accurate technique for the detection of fluid, it is widely used in the determination of fluid composition and properties. Through the innovation of this project, the application of NMR in the real-time and quantitative detection of multiphase flow in oil & gas wells and pipelines affected by flow state and adverse environment. The proposer's pre-research work obtains Gold Award of Beijing Innovation Contest and the National Excellent Doctoral Dissertation Nomination Award of the China Instrument and Control Society, with the foundation and the ability to carry out related research.

油气井及管道多相流流量的快速、准确、定量检测是世界油气工业共同面对的难题，潜力巨大。对高含水、含气生产流体的准确计量，一直是学术界和工业界努力的方向。现有仪器装置大多需先进行油、气、水三相分离，而且存在量程小、误差大、抗干扰能力差、工艺复杂等问题。本项目针对上述难题，提出多相流核磁共振在线检测的新装置和新方法，对“流动状态下的磁化效率与信号损失率控制”，“核磁共振信号快速采集脉冲序列”，“多相流在线检测数据处理与定量解释”等3个关键问题进行探索，研制原理样机，对新方法进行验证，形成油气井和管道多相流快速定量检测新技术。核磁共振可以对流体进行高效、准确探测，确定流体组分与性质，信息独特、用途广泛。本项目首次把核磁共振应用于受流动状态和恶劣环境影响的油气井及管道多相流的实时定量检测。申请人预研工作获得北京发明创新大赛金奖和中国仪器仪表学会全国优秀博士论文提名奖，具备开展相关研究的基础与能力。

油气井及管道多相流在线流量计量及流体性质化验是油气井管理、油藏动态分析及优化的基础，具有重大生产需求。针对目前油气田现场广泛采用的多相流分离检测及采样化验技术存在的效率低、精度差、数据延迟、环境污染等问题，研究并提出基于磁共振技术的多相流在线检测技术，包括：（1）磁共振多相流在线计量及化验方法，具体涵盖在线磁共振信息采集脉冲序列，磁共振多相流量及组分解释算法，磁共振多相流流体性质在线化验方法；（2）流动在线磁共振探头设计方法，具体涵盖多段式在线磁共振磁体设计方法，双天线设计方法，一体式谱仪设计方法；（3）应用于油田现场多应用场景的磁共振多相流在线计量及化验系列化装置，具体涵盖应用于生产井、试油试气井的磁共振多相流在线检测装置，便携式小型化磁共振多相流在线检测装置。该技术的实现突破了多相流非分离检测，磁共振在线测量，复杂工业环境下的磁共振装备等一系列技术难题，率先形成新方法及新装置。目前，系列化装置已在长庆油田、吉林油田、华北油田开展现场应用680余井次，应用场景包括：单井计量及化验、平台井计量及化验、试油试气计量及化验，实测液相流量计量误差小于3%，气相流量计量误差小于6%，同时可进行多相流密度、粘度、温度、压力等参数的实时检测。该技术的成功实现及应用，为油气多相流的高效、准确、绿色原位、在线检测提出了全新的方法，助力油田数字化、智能化转型，同时也标志着磁共振技术继石油测井之后在石油工业领域的又一个全新的应用方向。