The acoustic emission(AE)on-line monitoring tests of glass fiber reinforced plastic (FRP)specimens with fiber orientation of 0°,90°and ± 45°were carried out during tensile and bending mechanical damage.The results show that the fiber ply angle is the main factor for determing the mechanical properties and damage rules of FRP.The degree of grey relation between tensile force or bending force and amplitude can reach over 0.861.The signal amplitude and other parameters are used to judge the different damage stages of the specimen.There are obvious differences in waveform and spectrum between four typical AE signals produced by specimen damage.

针对大型储罐被动检测声发射信号弱的问题,根据声振法检测原理,选择常用的激励原材料(尼龙材料、不锈钢材料、塑料)对10 mm壁厚环氧树脂玻璃钢储罐进行主动敲击试验,筛选不锈钢作为最优激励源材料,设计了弹簧锤工装.利用设计工装对实验室玻璃钢储罐进行声振试验,对试验数据进行分析.结果表明:水平方向上的敲击信号传播速度最快且幅值衰减最小;随着方向角度增加,波速逐渐减小,幅值衰减速率逐渐增加;得到了声振信号波速传播模型、幅值衰减规律;总体上声振信号传播比被动声发射信号传播距离远,为玻璃钢储罐缺陷检测奠定了基础.

With glass fiber composite material as the research object,the regularity of frequency variation of acoustic emission wave in glass reinforced plastics was studied,and it was found that acoustic emission wave attenuation frequencies collected from different locations of the acoustic emission sources were concentrated in different areas.According to the theory of modal acoustic emission that acoustic emission signal propagation characteristics are different in different frequency ranges,acoustic emission wave was filtered by different passband filters,and the linear relationship about its time difference to each sensor were analyzed for the purpose of comparison,and hence a precise method of extracting the acoustic emission wave arrival time was obtained and it was found that the error of the mode filtering was significantly lower than the traditional time.

试验发现金属探测技术、磁应力检测技术、瞬变电磁检测技术等3种检测技术,对废弃井检测有较好的信号响应,探地雷达检测技术、PCM管道探测技术可以辅助排除金属管道等干扰信号.采用组合探测方案,应用标准化的探测流程成功定位了1201口废弃井,对其中的341口废弃井进行了开挖验证,312处井口定位准确,准确率达91.5％.

为克服瞬变电磁法检测埋地管道时局部腐蚀分辨率低、抗干扰能力差的缺点,利用磁信号聚焦技术对其进行改进.首先,给出矩形载流线圈磁场空间分布的计算公式;并利用改进的遗传算法对线圈阵列进行了设计.根据实际检测需求,设计了一种由三线圈组成的阵列.仿真结果表明阵列60％以上能量聚集于半径0.5 m的圆形区域内.阵列激励磁场测量结果表明,其聚集斑半径小于0.7 m,与传统瞬变电磁检测仪相比极大提高了管道局部腐蚀分辨率.

The leakages of buried pipelines often lead to damages of protective coatings and pipeline body.On the basis of rating of damages of external anti-corrosion protection coating of pipelines,the damaged pipelines were inspected by metal magnetic memory technique,which could effectively detect the leakages and stress concentration zone.The metal magnetic memory technique is an effective method for detecting the stress concentration zone of pipeline.To improve the signal-to-noise ratio of magnetic signals,Daubechies wavelet was applied to denoise the magnetic signals containing noise.Furthermore,the Hilbert transformation was used to analyze the signals and obtain its information features.The detection results of a leaking pipeline segment show that the error of localization of leakage position is less than ±1.0 m.

Underground metal pipeline leakage detection and positioning is an urgent technical problem. Usually,the leakage could cause the pipe wall to be deform and damage. The metal magnetic memory is an effectively method to detect the stress concentration. In order to extract the feature of pipeline leakage from the magnetic signals,a time-frequency analysis method has been proposed based on Hilbert–Huang Transform. Firstly,the Intrinsic Mode Functions(IMF,Mi(t))of magnetic signals were obtained using the empirical mode decomposed(EMD)algorithm. Then,through the separation and extraction of the different frequency components,the reconstructed signal by low-frequency Mi(t) would contain feature of pipeline leakage.Finally,the purpose has been realized to extract the feature of pipeline leakage according to analysis of the Hilbert envelope spectrum. The favorable recognition precision ratio and the validity of extraction feature of pipeline leakage were verified by the experiments. Furthermore,experimental results indicate that the pressure and leakage could not affect the extraction feature.The results of in-situ show that the accuracy of leakage positioning is less than±1.0 m.

The defect quantified classification standard for buried pipeline external coatings has not been established at home and abroad. In this paper, an accurate evaluation method for external coatings was proposed by the method of calibration data of AC voltage gradient (ACVG). Based on the principle of ACVG detection, a physical model of pipeline anti-corrosion layer detection was established. Therefore, a voltage calculation formula between poles was derived. By using the calculation formula, the ACVG data were revised for the tested pipeline. By using the corrected data of AC voltage gradient, the long-distance buried pipeline layer damage can be accessed accurately.

针对瞬变电磁法（TEM）在埋地金属管道金属蚀失量检测中,由于每个检测点覆盖的管道距离较长,难以满足实际检测精度需求的现状,对磁场信号的聚焦加载技术进行研究。基于经颅脑刺激用磁聚焦线圈技术,设计了一种适用于埋地金属管道检测的线圈阵列,并利用遗传算法对线圈阵列的电流大小及相位进行优化,给出了线圈阵列在计算区域内的磁场分布和二维等高线图,数值计算结果表明:该线圈阵列在计算区域产生的磁场具有良好的聚焦功能,可用于埋地金属管道腐蚀检测。

Based on detail analysis of possible corrosion failure in long - distance crude oil pipelines, an appropriate applicable technology, which applies PCM（ dual）, DCVG, CIPS, SCM and TEM, is proposed. Cases are studied to illustrate the application of this technology. The results show that, by this technology, the corrosion and protection status of long - distance crude oil pipelines can be completely evaluated without excavation and shutdown of pipeline operation. This will help to improve the safety of the long - distance crude oil pipeline transportation and provide guidelines for pipeline maintenance, repair and replacement.

The ultrasonic guided wave based on magnetostrictive sensor(MsS) technology was used to detect the condition of platform jackets.The results show that the MsS technology can realize rapid detection of the full length of the jacket.Because high frequency can interact with horizontal structure linked jackets,the ultrasonic guided wave using low frequency will be more helpful to analyze the data.The corrosion of the jackets focused on two regions.The first one was within the first 2 meters below the water line.The second one was close to the sea floor.

胜利油田腐蚀与防护研究所综合利用管线探测法、电流梯度法、电位梯度法、皮尔逊法、探地雷达检测法、燃气浓度比较法及红外测温法等多种检测技术,对胜利油田某位于城市繁华地段的埋地原油外输管道进行了泄漏检测抢险。本文详细介绍了检测抢险以及开挖验证的全过程,为油田类似埋地管道泄漏事故的快速抢险提供了经验借鉴。

The paper provides 3 special external inspection techniques to detect the pipe wall thickness and pipe defects for buried pipelines in oilfield, that is, pulse transient evaluation method, long-spacing guided wave inspection method and spot check with ultrasonic wave inspection. Advantages and disadvantages of these techniques are analyzed and compared. Through application of these inspection techniques at Shengli Oilfield and abroad, applicable scope of these techniques is given, which has guiding significance for pipe corrosion and defect inspection in oilfields' pipeline and warning of pipeline leaking accident.

The common leak detection methods and advanced technologies for buried pipelines both in China and abroad are introduced.In a case study,the application of leak detection technology in SINOPEC Shengli Oil Field Company is described,and appropriate combination leak detection technologies were selected for the buried pipelines of different transportation media(oil,water and gas),which are very important for the rapid response to the leak emergency in buried pipeline operation.

The work activities and years'experience of Research Institute of Corrosion and Protection of Shengli Oil Field in corrosion detection and prevention of buried oil pipelines in oil fields are studied.The common corrosion types,aging of corrosion protection layer,failure causes and corrosion of pipelines in domestic oil fields are analyzed.Effective corrosion protection and prevention measures are recommended in respect of material section,design and construction,process corrosion protection and proper operation of production equipment,etc.The development orientation of corrosion detection and prevention technologies for oil field pipelines are predicted.

The 47 subsea pipelines in Shengli Chengdao Oil Field are badly in need of corrosion detection and evaluation.Whereas the detection technologies developed for the subsea pipelines and their applications are not commercially proven.A detection and control schemes are proposed for both operating and newly-built subsea pipelines based upon the corrosion detection experience and optimization of analysis and control technologies,such as testing of corrosiveness of platform production streams and corrosion inhibitor evaluation,the internal corrosion of subsea pipelines,the detection of corrosion,damages,deformation and overhang of subsea pipelines by underwater imaging technology,and proper selection of pipeline materials and pipeline foundation liquefaction monitoring,etc.

Several analytical methods and testing means, including water quality analysis, bacteria testing, water corrosiveness testing, corrosion products, scale component analysis and corrosion rate testing, were ap- plied to study corrosion reasons of the water injection system at Dongxin Yong 921 Joint Station. The main reasons were indicated to be dissolved oxygen plus Ca2+/HCO3- system corrosion, combined effect of TGB and SRB, and speeding up subscale corrosion by large amount of Cl-. Through screening and evaluating corrosion inhibitors, IMC-07 concentration of 40 mg/L was chosen as a suitable inhibitor which could control the corro- sion rate within 0.076 mm/a and get corrosion inhibition efficiency more than 85% for deep well water, shallow well water or their mixed water.

A series of field tests including routine performancetesting, high-temperature and high-pressure dynamic corrosive test, electrochemical impedance spectroscopy measurement,and pilot test in the presence of flowing fluids in pipes were carried out to evaluate the performance of a new type nano-Ti-Ta alloy/epoxy resin anticorrosion coatings. Results indicated that the coating was qualified in terms of various properties tested according to relevant national standard methods. And it had good anticorrosionbehavior and was capable of inhibiting scales at high-temperatureand high-pressure or in the presence of flowing fluids in pipes. Hopefully, the coating would find promising application underconditions of ensured painting process and reliable operation.

The corrosion of oil pipelines in Ken-32 block of Shengli Oil Field is typical needle hole corrosion.Although it does not impose a thread to the safe operation of the pipelines,it is very difficult to deal with due to complicated formation causes.The failed pipes are analyzed and corrosion causes are studied.The study shows that the major culprits of pit corrosion are the impurities in pipe material and under-deposit corrosion inside the pipes.In addition,the possible electric potential difference in separated pipeline construction also plays a role in corrosion.

Corrosion inspections without excavation were carried out for 19.92 km oil pipeline from Chunliang first station to Shinan station at Chunliang Oil Production Plant of Shengli Oilfield. Many techniques such as detecting pipeline leakages, locating fracture spots at anticorrosion and thermal insulation layers, identifying anode corrosion tendency points and detecting assessment of remained pipe wall thickness were applied. The alignment and buried depth of the pipeline were exactly positioned. The concrete positions needed for replacement or rehabilitation as well as needed for monitor or maintenance were confirmed. The inspection provided a technical foundation for replacement, rehabilitation and maintenance of pipeline.