【作者】 杨少鹏；

【导师】 董惠娟；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2013， 硕士

【摘要】 石油是国家战略性资源，在石油开采中，生产井动液面是一项重要的油井管理基础资料，动液面反映井底流动压力、液柱高度和泵的沉没度，动液面高度、泡沫段长度及性质对于采油过程有着十分重大的指导意义。但是目前动液面监测技术有着重大缺陷：对于无泡沫段井，监测精度较低，不能实现实时在线监测；对于含泡沫段井，无法准确监测动液面位置，也无法得知泡沫段性质。本文基于光纤传感理论，利用光纤抗电磁干扰、耐腐蚀、安全性好、长距离监测、可实现分布式传感等优点，针对无泡沫段井和含泡沫段井分别提出一种动液面监测方案，结合两种方案实现动液面位置和泡沫段长度、密度、含气量等多参数的实时在线监测。针对无泡沫段井，设计了一种平膜片—等强度梁动液面监测传感器，建立了动液面高度与光纤布拉格光栅（Fiber Bragg Grating，简称FBG）中心波长变化量之间的关系。设计的传感器可实现温度自补偿，各项性能满足设计指标。利用ANSYS软件对传感器进行了静力学仿真，传感器力学性能符合要求，仿真值与理论值相符。针对含泡沫段井，提出了一种伴热带辅助加热法监测动液面方案。利用传热学原理推导了热源发热时间与周边介质温度响应之间的关系。基于光纤拉曼散射（ROTDR）只受温度解调的原理，监测热源发热后不同周边介质的不同温升，实现动液面位置和泡沫段长度的监测。利用ANSYS软件对伴热带加热模型进行非稳态传热仿真，验证了伴热带辅助加热法监测动液面的可行性。结合两种方案，建立分布式光纤拉曼传感系统和准分布式传感器系统，推导了泡沫段各层段平均密度、含气量的理论公式，从而实现了动液面位置、泡沫段长度、泡沫段各层段密度、泡沫段各层段含气量等信息的实时在线监测。最后，进行了实验。研制的平膜片—等强度梁动液面监测传感器尺寸小巧、线性度良好、灵敏度高。针对空气和水进行了气液两相伴热带辅助加热法实验，实验结果与理论推导、ANSYS仿真结果相符，存在的误差不影响此方法对于动液面的监测，可以较好的满足动液面监测要求。更多还原

【Abstract】 Oil is a national strategic resource. In the oil exploitation, production wellworking fluid level is an important fundamental date of well management. Workingfluid level reflects bottom hole flowing pressure, height of liquid column,submergence depth of well. Height of working fluid level, length and properties offoam section have a very important guiding significance in the oil extraction. Butthe current monitoring technique for working fluid level have significant deficiency.For wells without foam section, monitoring accuracy is low, and unable to achievereal-time on-line monitoring. For wells with foam section, unable to accuratelymonitor the position of working fluid level, and unable to know properties of thefoam segments.This article is based on the theory of optical fiber sensing, on the basis ofoptical properties, such as, electromagnetic interference resistance, corrosionresistance, safety, long-distance monitoring, enabling distributed sensing, etc,presents monitoring programs for no foam segment wells and wells containing foamsection. Combination of two solutions is able to achieve the real-time on-linemonitoring of the position of working fluid level, the length, density and gascontent of foam segment.This article designs a flat diaphragm-equal strength beam sensor to monitor theworking fluid level of wells without foam segment. Establishing the relationbetween height of working fluid level and the centre wavelength of FBG (FiberBragg Grating, FBG for short). Designed sensor has the function of temperatureself-compensation, the performance can meet the design specifications. The staticsanalysis of sensor is made using ANSYS, mechanical properties meet therequirements and the simulation agree well with the theoretical value.For wells containing foam section, proposing a method of electric tracing bandauxiliary heating to monitor the working fluid level. Derived the relation betweenheat source heating time and temperature response of surrounding medium usingheat transfer theory. Based on principle that Raman Optical Time DomainReflectometer (ROTDR for short) only demodulated by the temperature, monitoringdifferent temperature rise in different surrounding medium can monitor the positionof working fluid level and the length of foam section. Non steady heat transferanalysis using ANSYS proved that electric tracing band auxiliary heating to monitorthe working fluid level is feasible.Combining the two programs to create distributed fiber Raman sensor systemand the quasi-distributed sensor system, derived theoretical formula of average density and gas content of foam section. Then the real-time on-line monitoring ofthe position of working fluid level, the length, density and gas content of foamsegment can be achieved. At last, the experiments are made. Designed sensor isvery small in size, its linearity is well and sensitivity is high. Gas-liquid experimentof electric tracing band auxiliary heating is made for air and water, experimentalresults and theoretical analysis, ANSYS simulation results generally in line, theerror does not affect the result of this method for monitoring of working fluid level,and the method can meet the monitoring requirements.更多还原