题名 | 新型井下超声石油流量计的设计与实现 |
作者 | 王德龙 |
学位类别 | 博士 |
答辩日期 | 2003 |
授予单位 | 中国科学院声学研究所 |
授予地点 | 中国科学院声学研究所 |
关键词 | 超声流量计 井下仪器 |
中文摘要 | 声波方法是测井的重要手段之一。在井下石油流量测量中,要求测流装置具有较宽的动态范围和很高的测量精度,同时井下原油勃度大,不导电,不能使用传统的涡轮式或电磁式流量计。而超声流量计因为具有可进行非接触式测量和测量精度高等优点,适合用于井下特定环境下的石油流量测量。而传统井下超声流量计的超声换能器采用正对布放方式,这种方式可以获得较高信噪比的超声信号,但它对流场的改变很大,同时当被测流体为赫度较高的油时,换能器表面会有粘附,这些均会影响测流的精度。本文设计了一种新型的井下石油超声流量计,超声换能器布放方式采用新型的内置倾斜式布放方式,利用时差法的测流方法,减小超声石油流量计对流场稳定性的影响,提高测量精度。在井下石油超声流量计的井下仪器设计中首次使用了一种新型的车用温度级(-40℃至+125℃)CPLD(complexProgammableLogicDevice)器件代替分立元件,简化了超声波流量计的电路设计,解决了井下仪体积和温度的要求,提高了系统的稳定性和测量精度。同时采用曼彻斯特编码技术很好地解决了井下特殊环境下超长距离信息采集处理及传输等问题。 |
英文摘要 | Acoustic Logging is regarded as one of the most important techniques of logging. In the measurement of flux of petroleum downhole, a wide dynamic range and an extraordinarily high precision are needed for the measuring instrument. In the meantime, the high viscosity of crude oil downhole and its dielectric characteristic lead to the inapplicability of traditional turbine flowmeter and electromagnetic flowmeter. However, ultrasonic flowmeter can accomplish untouched measurement and a measurement with high precision, which lead to its widely application in the measurement of flow of petroleum downhole. For traditional ultrasonic flowmeter, the ultrasonic transducers are placed face to face. In this way, signals with high SNR (Signal Noise Ratio) can be obtained. However, the placement of transducers itself also brings on great influence to the flow field, and the crude oil with high viscosity will stick to the surface of transducers, introducing the deflection of precision of measurement. In this thesis, a new downhole petroleum ultrasonic flowmeter is designed and fabricated, in which the transducers are deflected with an angle. The influence of flowmeter to the stability of field is reduced, and the precision of measurement is improved by adopting Traveling Time Difference Method. In the designing of the downhole petroleum ultrasonic flowmeter, for the first time discrete devices are substituted with a new type Automatic Temperature (-40°c~125°c) CPLD (Complex Programmable Logic Device), which simplifies the circuit designing of the flowmeter, and leads to the satisfaction of volume and temperature demands, and the improvement of stability of the system and the precision of measurement. Also, the adoption of the method of Manchester Coding helps to settle commendably the problem of signal collection and transmission over long distances in the special downhole environment. |
语种 | 中文 |
公开日期 | 2011-05-07 |
页码 | 40 |
内容类型 | 学位论文 |
源URL | [http://159.226.59.140/handle/311008/1092] ![]() |
专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
推荐引用方式 GB/T 7714 | 王德龙. 新型井下超声石油流量计的设计与实现[D]. 中国科学院声学研究所. 中国科学院声学研究所. 2003. |
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