油水两相螺旋流状态下射频法测量原油含水率的方法

目前,国内大多数油田进入采油后期,原油含水率显著提高,对含水率的测量提出了新的挑战。针对原油含水率的实时测量问题,提出了一种油水两相螺旋流状态下射频法测量含水率的新方法。首先将油水两相来流通过旋流器调整成螺旋流状态,然后测量螺旋流状态下管内同心布置的天线发射的射频信号,最后通过建立含水率与射频信号之间的关系模型及两相流速度滑移模型对测量结果进行修正,得到含水率的测量结果。该方法能够消除油水两相流型分布不均匀对测量结果的影响,扩宽了含水率的测量范围。通过室内实验的方法对测量模型进行了静态标定、动态验证和优化调整。实验结果表明,在入口油水两相混合流速为0.60~1.20 m/s,体积含水率高于43.81%时,利用该方法测量含水率误差在6.29%以内。

Water content measurement by radio frequency method under the condition of oil-water two-phase spiral flow

At present, most oilfields in China have entered the late stage of oil recovery, and the water content of crude oil has increased significantly, which has brought new challenges to the measurement of water content. For the problem of real-time measurement of water content of crude oil, this paper proposes a new method of water content measurement by radio frequency method under oil-water two-phase spiral flow. First, the oil-water two-phase flow is adjusted to a spiral flow state by a cyclone, then the radio frequency signal emitted by the antenna arranged concentrically in the tube under the spiral flow state is measured, and finally the water content ratio is achieved by establishing a relationship model between the water content and the RF signal measuring. This method can eliminate the influence of the oil-water two-phase flow pattern on the measurement results and widen the measurement range of the water content. The measurement model was statically calibrated, dynamically verified, and optimized through laboratory experiments. The experimental results show that when the inlet oil-water two-phase mixing flow rate is 0.60-1.20 m/s and the volumetric water content is higher than 43.81%, the error of the oil-water two-phase measurement using this method is within 6.29%.