为了实现油井开发的高效率开采、科学化经营与精细化管理，流量与含水率的准确测量非常关键，有助于更好的掌握产液剖面数据、评估油藏区储油量。目前，多相分离计量技术仍为国内油井采用的主流测量方法，依托于工艺结构复杂的多相传感器，其仪表设备占地较大，无法在井下安装实现，且受井下流体复杂多变的流态影响，其测量精度与实时性均难以满足需求。

分布式光纤声学传感技术集传感测量与信号传输功能于一体，光纤测量沿线振动信号用于计算流量与相含率，该方法被广泛用于国外高产量油井中多相流量的测量。然而，受井下安装环境限制，通常直接将光纤光缆沿油管套筒外壁直线布设，安装方便但对流量的测量精度低，尤其应用于国内小流量低产井时，因流量引起的有效振动信号几乎被“嘈杂”的井下环境噪声淹没，导致后期数据处理困难，甚至无法解析。针对上述问题，本文提出一种缠绕光纤两相流量传感结构，以缠绕方式代替直线布设方式来采集油管振动信号；然后对光纤缠绕参数进行理论计算，得出最优缠绕方式，从而提高管壁振动信号测量灵敏度，以及获取更准确的流体声波信号；最终进行油水两相流量实验，将管壁振动信号用于流量反演，流体声波信号用于含水率计算，验证了缠绕光纤传感结构对井下流量、含水率同时测量的可行性。本文的主要研究内容如下：

（1）对管道内油水两相混合流量与含水率测量理论进行研究。首先根据湍流强度理论得到压力波动与平均流量成正比，进一步分析充满湍流的管道横向振动、管壁动态应变分别与流体压力波动的关系，得到管壁振动信号标准差与管内流量之间呈二次线性关系。再基于线性模型计算得到湍流内声速与相含率之间的数学关系式，并结合多普勒频移推导了分布式光纤传感器测量声速的原理。其次对不同流速、含水率下的油水两相流体进行仿真，分析压力场情况，发现流体外表面压力受流速变化的影响大，受相含率变化的影响小，验证了由管壁振动信号测量两相混合流量的可行性。

（2）对分布式光纤声学传感（Distributed Acoustic Sensing，DAS）系统解调采集声波信号及管壁振动信号的方法进行研究。以缠绕在管壁上的光纤为研究目标，管壁受到均匀压力场作用时，对光纤的应变效应以及弹光效应进行定量分析，得到管壁压力场与缠绕在管壁上的光纤相位差之间呈一次线性关系。接着，对DAS系统进行幅频响应实验来测试DAS对振动信号的响应程度，测得有效频率范围达500Hz，光纤轴向拉伸量与DAS系统幅值之间关系系数为0.028rad/μm，为缠绕光纤结构的测量参数分析提供了理论支撑。

（3）提出了一种缠绕光纤两相流量传感结构，可同时测量油水两相的流量与含水率。首先进行缠绕方式研究，优化螺距、紧密缠绕圈数这两个参数，从而提高缠绕光纤对管壁动态应变的测量灵敏度，并使得声波的声速更易被测量，最终得到2-3 cm螺距、4-6圈紧密缠绕圈数为最优缠绕方式。然后选取了全紧密缠绕、全螺距缠绕以及最优参数下的半紧密半螺距缠绕，共三种缠绕方式，分析其缠绕特性与测量特性，证实了理论分析的可靠性与准确性。

（4）基于缠绕光纤传感结构进行油水两相流量实验测试，通过DAS解调得到的管壁振动信号与流体声波信号，流量测试范围为2-16 m³/h，含油率测试范围为10%-90%。流量测试结果表明，三种缠绕方式下均满足DAS幅值标准差与流量之间呈二次线性关系，且拟合度达90%以上；同时，在4-16 m³/h流量范围内，全紧密缠绕测量误差稳定为±5%以内，全螺距缠绕误差在±10%以内，最优缠绕方式下的误差在±6%以内。含水率测试结果表明，在含油率30%-90%，最优缠绕方式下的声速-含油率曲线与理论模型计算得到的参考曲线具有几乎相同的变化趋势，对两者进行一次线性拟合，拟合斜率为-374.1与-420.1。由此可得，缠绕光纤传感结构可同时完成油水两相流量、含水率两个参数的准确测量。

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