基于内检测数据的天然气管道腐蚀缺陷评价

以内检测数据为基础，对腐蚀缺陷的评价方法进行了梳理与应用。腐蚀缺陷评价流程包括数据采集、内检测数据统计与分析、腐蚀缺陷剩余强度评价及维修决策。基于工程实例，对某天然气管道进行腐蚀缺陷评价，分析了腐蚀缺陷数量、长度、深度沿检测里程的分布及腐蚀数量与管道高程的关系，掌握了需重点关注的管段。对此管道进行剩余强度评价及维修策略制定，结果为目前不需要立即维修，但在12年后，腐蚀缺陷不能满足管道安全运行，需进行计划维修。     

井下油管的防腐措施

井下油管腐蚀受诸多因素影响,其中最主要腐蚀形式是H2S腐蚀和CO2腐蚀,并且以H2S、CO2共存时的腐蚀最为普遍,过程也最为复杂。针对目前油气田井下油管腐蚀现状,对其腐蚀机理及防腐措施进行了探讨。     

高压大通径井下安全阀功能检测

在石油设备及工具的设计、制造及采购过程中,满足API规范的产品得到了广大客户的认可.井下安全阀[1]是防止井喷、保证油田安全生产的一种重要井下工具,其功能是否完好,直接决定海上油气田的生产安全,因此,井下安全阀产品在出厂或按标准[2]维修后,需要严格遵守API Spec 14A井下安全阀规范[3]要求进行功能检验.随着中海油南海高油气田的开发,对高压大通径油管回收式井下安全阀[4](SCSSV)的需求也逐年递增.主要讲述高压大通径油管回收式井下安全阀(SCSSV)产品进行功能检测的项目和测试结果判定.     

油管杆防腐防垢的研究与应用

在对油管杆腐蚀状况进行调查和研究的基础之上,总结出了油管油杆腐蚀的一般规律以及相应的典型性。并对油管油杆腐蚀类型腐蚀机理以及腐蚀的影响因素的研究基础之上,提出了有效的防腐蚀防垢技术措施,从而能有效提高油气田防腐工艺技术水平,有一定的使用以及参考价值。     

数字化磁性无损油管检测技术在大港南部油田的应用

由于腐蚀、磨损等原因,在用油管中不同程度存在孔洞、裂纹、锈蚀、磨损等缺陷,这些缺陷长期受交变载荷作用,容易产生疲劳损伤,导致油管的泄漏甚至断裂,使采油成本大幅度上升,近年来在大港南部油田试验应用了数字化磁性无损油管在线检测技术。通过对52240根油管的现场检测试验,检测出有缺陷油管12455根,该技术对油管内、外壁的腐蚀坑点、孔洞及管壁偏磨等缺陷均做出了准确定性分析,对油管进行选择性更换提供了科学依据。     

海上油气田硫化氢防治工艺优化实践

硫化氢对油气田设备、管道具有较强的腐蚀作用,影响生产安全。本文对海上油气田硫化氢的腐蚀机理以及当前主要综合防治方法进行分析,重点研究了负压闪蒸法脱硫的技术原理及应用情况,为海上油气田脱硫找到一条经济适用、高效率的途径,可为海上油气开采运输过程中的脱硫提供借鉴。     

浅谈油管偏磨腐蚀研究

近些年来,各个油田出现油管偏磨腐蚀的情况越来越严重,偏磨导致正常的工作时间受到影响,维修投入的增加,最终导致企业的综合效益无法提升。所以需要对油管偏磨腐蚀的原因与机理进行研究,对避免或者降低偏磨腐蚀的对策进行分析,才能缓解油管偏磨腐蚀带来的不利影响。     

水平井腐蚀油管打捞工艺研究

气井作业过程中井内流体对井内油管存在腐蚀现象,导致油管出现管壁变薄、穿孔甚至断裂现象的发生,严重影响气井正常生产及后期的施工作业,同时也会对天然气开采的施工安全带来重大影响,需要将已腐蚀油管打捞出井筒。选取国内某气田发生油管腐蚀的水平井为研究对象,通过分析打捞施工过程中存在的问题,总结打捞过程及技术要点。     

庆哈输油管道腐蚀规律研究

由于长距离输油管道的长度较长,跨度较大,各管段周围土壤环境及类型不尽相同,导致各段的腐蚀类型和腐蚀速率也会有所区别。对长距离输油管道进行不同管段下的腐蚀规律研究分析,为现场管道腐蚀防护及维抢修提供理论指导,对确保管道安全运行具有重要意义。     

气密封BGT合金油管推荐做法探讨

松南气田含CO_2气井开发生产中出现套压异常升高问题,对生产套管、采气树、工具存在酸性腐蚀,影响安全生产及开发。通过生产井进行了统计和分析,对现场操作进行了调查和跟踪,结合BGT合金油管生产厂家的要求和普光气田下油管的做法进行了研究和探索,结合松南气田的实际生产情况,提出BGT合金油管推荐做法。     

Fracture Criterion for Alumina Ceramics Subjected to Triaxial Stresses

Triaxial stress tests of alumina ceramics were conducted by pure bending under hydrostatic pressure, and by internal pressurization of an open-end thin-walled tube under hydrostatic pressure. The fracture stresses plotted in the principal stress space did not conform to existing fracture criteria. So, for fracture of the material, the flaw model consisting of randomly oriented penny-shaped cracks was assumed. The fracture criterion obtained from a statistical viewpoint by taking account of flaw distributions could explain well the experimental results.     

新型结构蒸发器的制造

蒸发器管程为蛇形加热管线。管束是蒸发器的核心部件 ,制造管束的关键是控制异径管以及异径管与封头管板的焊接质量。加热管线通过异径管的套管与封头管板相连接。异径管的套管与管板的连接是挠性结构 ,改善了连接点的应力状况 ;U形管的中心距和管板、支持板的中心距必须保持一致。加热管的对接焊缝必须进行 10 0 %射线探伤。由于管孔和U形弯头的中心距较小 ,异径管与封头之间的空间有限 ,为方便换热管与异径管、封头管板与异径管的焊接 ,采取从上到下 ,按排组焊、无损探伤的组装方法     

Strength Evaluation of Reaction-Bonded Silicon Carbide Radiant Tubes after Long-Term Exposure to Combustion and Endothermic Gas Ambients

The strengths of reaction-bonded silicon carbide radiant tubes were examined after a 14-month campaign at 800°–950°C in an industrial heat-treating furnace. The inner tube of the single-ended radiant tube (SER) burner system was exposed to a combustion gas environment, and the outer tube was exposed to both a combustion gas (inner surface) and an endothermic gas (outer surface) environment. Diametral compression testing of C-rings and O-rings was employed to assess the effect of exposure on the strengths where failure initiated from the outer and inner surfaces of the tubes, respectively. Comparisons of strengths obtained on exposed versus as-received tubes revealed that exposure to the combustion ambient yields an apparent moderate strengthening, with a concurrent increase in strength variability. No significant difference in strength distribution was observed for tubes exposed to combustion versus endothermic gas ambients. Failure most often originated at silicon-rich regions remaining from silicon infiltration of macroporosity in the slip cast tubes during reaction sintering. Specimens sectioned from the outer tube exhibited unexpectedly high strengths (based on predictions from Weibull statistics) compared to those sectioned from the smaller inner tube after the same exposure. These results indicate that the larger tubes have flaws with characteristics different from those present in smaller tubes, and underscore the need to use data from the same material, with the same flaw populations, in making predictions of the effect of component size on strength distributions and reliability in service.     

Time-Dependent Strength of Siliconized Silicon Carbide under Stress at 1000° and 1100°C

The time-dependent strength of a fine-grained siliconized silicon carbide under stress at 1000° and 1100°C was investigated. Both macroscopic stress redistribution and localized flaw blunting were found to contribute to the strengthening of siliconized silicon carbide in bending tests. Strengthening through macroscopic stress redistribution involved nonlinear creep behavior which decreased the maximum outer fiber stress in the bending beam. Localized flaw blunting processes were determined to be operative in this material through artificial flaw tests using a prestress to prevent flaw healing. The sharp artificial cracks were blunted during static load tests by localized deformation processes at the crack tip.     

用于细颗粒分离的水力旋流器的压力特性研究

对用于细颗粒分离的水力旋流器的压力特性 (压力降及压降比 )与流量、分流比、旋数、溢流口和底流口直径及气液比等主要参数之间的关系进行了深入的研究与分析。研究发现 ,水力旋流器内部压力降分别随流量、分流比、旋数及气液比的提高而加大 ,压降比则分别随流量、分流比、旋数的提高而降低。随着溢流口直径的加大 ,水力旋流器的溢流压力降减小 ,而压降比也随之降低 ;随着底流口直径的加大 ,底流压力降减小 ,压降比随之升高。分析可知 ,减少旋流器能耗的有效方法是降低旋数 ,或者减少混合介质中的气液比     

超声波全自动探伤电气控制与应用

在超声波探伤工艺中为了减少检测盲区,主要由传感器对现场的信号进行采集,用PLC编程软件实现钢管追尾、自动分选等工艺步骤,由变频器对辊道电机传动加以速度控制。采用变频调速后产生的电磁干扰加上生产现场其他各种干扰,引起超声探伤仪出现误报警,因此采取了一系列抗干扰措施。     

Discrete element simulation of SiC ceramic containing a single pre-existing flaw under uniaxial compression

A model of a SiC ceramic containing a single pre-existing flaw was established based on the discrete element method. The effects of the flaw inclination angles, which ranged from 0° to 75°, on the mechanical properties of the specimen under uniaxial compression were studied. The evolution of the force-chain field, displacement field and stress field around the pre-existing flaw in the process from the load to failure was also analysed. The results showed that the flaw inclination angle affected the mechanical properties of the specimen as well as the initiation and propagation of the first crack. Based on the investigation of the force chain field, it was found that the distribution curve of the normal force carried by the parallel bond in the specimen with the corresponding angles under compression is similar to the “peanut” rose diagram, while the shear force distribution curve is similar to the "butterfly wings" rose diagram. In addition, in the analysis of the displacement field and the stress field, the displacement field around the flaw can be divided into four types in the process from specimen loading to its failure. Meanwhile, it was found that initiation of the first crack was affected by tensile stress. With the propagation of the first crack, the tensile stress concentration region at the flaw tip moved and dissipated correspondingly.     

基于连续小波变换的输油管道裂纹缺陷漏磁检测研究

在分析埋地输油管道裂纹漏磁检测现状的基础上,研究了连续小波变换能量法在管道裂纹漏磁检测信号处理上的应用。设计了裂纹缺陷漏磁检测实验方案,利用连续小波变换分析了裂纹缺陷不同特征参量(长度和深度)对漏磁检测信号的影响,得出了不同特征参量的裂纹漏磁信号的连续小波变换能量变化图谱,表明了漏磁检测信号特征与裂纹缺陷之间有特定的定量关系及用漏磁方法检测裂纹缺陷存在着一定的局限性。     

Microstructure, Flaw Tolerance, and Reliability of Ce-TZP and Y-TZP Ceramics

Ce-TZP and Y-TZP ceramics were heat-treated for various times and temperatures in order to vary the microstructure. Flaw tolerance was investigated using the indentation–strength test. Reliability was quantified using conventional two-parameter Weibull statistics. Some Ce-TZP specimens were indented at slightly elevated temperatures where no transformation was observed. Results indicated that the Ce-TZP specimens were extremely flaw tolerant, and showed a relatively high Weibull modulus that scaled with both R -curve behavior and flaw tolerance. Y-TZP, on the other hand, with very little if any R -curve behavior or flaw tolerance, had a low Weibull modulus. The results also show that flaw history, i.e., whether or not a transformation zone exists along the wake of the crack, has a significant influence on strength. Strength was much less dependent on initial crack size when the crack had an associated transformation zone, whereas strength was highly dependent on cracks typical of natural processing defects. It is argued that the improvement in reliability, flaw tolerance, and dependence on flaw history are all ramifications of pronounced R -curve behavior.     

中温固化复合材料层压板分层缺陷注射修补工艺研究

通过预埋石英砂,制备了复合材料层压板分层缺陷试样。采用注射修补法对分层缺陷试样进行了修补。使用电钻在缺陷试样单侧打注胶孔,通过注胶孔将DG-8胶黏剂注入缺陷区域,利用热补仪将注胶后的试样固化。对修补后的试样进行了无损检测、力学性能测试和微观结构分析。结果表明,修补后的试样拉伸和压缩强度恢复率均达85%以上,试样修补区的DG-8胶黏剂固化良好。