井筒内复杂流态下分布式微波传感器持水率测井方法研究

多井型井筒内流态多样性以及液滴界面拓扑变化、击碎分散与聚并等复杂非均相动态过程，给产液剖面持水率测量提出了新挑战。依据油水介质中的水极性分子不同频段电磁波作用下的介电特性，本项目开展分布式微波传感器持水率测井方法研究。为了适应井筒内油水两相流分散相空间分布复杂多变的持水率测量要求，首先，采用有限元法优化设计两种分布式微波传感器结构，即交错双螺旋式微波传感器及网状贴壁式微波谐振传感器。在研制传感器测量系统基础上，在多相流试验装置开展持水率实验测量，基于微波信号实现流型辨识，综合微波传感器幅度及相位信息联合解耦水相电导率及持水率，实现持水率测量过程中水矿化度变化自动补偿。本项目探索井筒复杂流态下分布式微波传感器持水率测井新方法，克服传统电导法或电容法持水率传感机理带来的多样性及复杂性困难，提高工作频率抑制传导电流对持水率测量影响，为井筒复杂流态下产液剖面持水率测井探索新方法，开拓新途径。

In multi-well wellbore, the complex heterogeneous dynamic processes such as the diversity of flow patterns, droplet interface topological changes, crushing dispersion and coalescence have presented new challenges to the measurement of water holdup in pruduction profile of production logging. According to the dielectric property of water polar molecules in oil-water medium under the action of electromagnetic waves in different frequency bands, this project intends to carry out the research on the measurement method of water holdup using distributed microwave sensors. In order to meet the requirements of high resolution measurement of water holdup under the complex spatial distribution of dispersed phase of oil-water flows in wellbore, firstly, the finite element method is used to optimize the design of two kinds of distributed microwave sensor structures, namely, the staggered double-helix microwave sensor and the netted wall-mounted microwave resonance sensor. Based on the development of the sensor measurement system, the experimental study on the water holdup of microwave sensor is carried out on the multiphase flow test facility. And the flow pattern identification is realized based on microwave signal. Then Combining the amplitude and phase measurement information of the microwave sensor, the conductivity and holdup of water phase are analyzed, thus the automatic compensation for the change of water salinity during the measurement of water holdup is realized. In this project, a new method for measuring water holdup in wells with complex flow patterns using distributed microwave sensors was explored. The new method we proposed can overcome the difficulty of diversity and complexity caused by the traditional conductivity or capacitance sensing mechanism, and the influence of conduction current on water holdup measurement can be suppressed via increasing the working frequency, what is more, this study will investigate a new method and way for measuring the water holdup of fluid production profile under the complex flow condition of wellbore.