针对Φ88.9 mm×6.45 mm L80-13Cr油管穿孔现象,采用宏观分析、化学成分分析、金相分析、力学性能测试及扫描电子显微镜、能谱仪等手段,对规格为Φ88.9 mm×6.45 mm的L80-13Cr马氏体不锈钢油管发生穿孔的原因进行了分析.结果表明:该油管材质的化学成分、显微组织及力学性能等未见异常,但内壁存在严重的均匀腐蚀以及孔蚀,腐蚀形貌呈苔地状,腐蚀产物及腐蚀坑内填充物主要为Fe3O4、FeOOH、FeCr2O4及CrOOH.因此穿孔的发生主要是由于油管内壁的水中存在溶解氧,导致油管发生了严重的均匀腐蚀及孔蚀,孔蚀处壁厚减少,导致油管穿孔.

利用热电偶和函数记录仪等设备测定了单丝埋弧堆焊X80管线钢板的热循环曲线,获得的热循环参数包括加热速度、峰值温度、高温停留时间和冷却时间t8/5.通过进—步分析得到了电流、焊速与热循环参数之间的关系,为合理制定X80管线钢的焊接工艺提供了重要依据.

With increasing needs of SAWL pipe,the analysis and research of SAWL pipe performance properties is very important.In this paper,the X100 SAWL pipe produced by a foreign steel plant was carried out a series of analysis,including tensile,impact toughness and hardness tests for base metal and welded joint,combined with metallographic analysis,integrated assessment for microstructure and properties of steel was conducted.The results showed that the ensile strength of SAWL pipe welded joints is close to that of base metal,the microhardness of weld metal is higher than that of base metal,and the micro-hardness in HAZ is lower than that of base metal.The submerged arc weld metal is with good toughness,the ductile-brittle transition temperature is-60～-50 ℃,and the ductile-brittle transition temperature in HAZ is-30～-20 ℃.

With increasing needs of SAWL pipe,the analysis and research of SAWL pipe performance properties is very important.In this paper,the X100 SAWL pipe produced by a foreign steel plant was carried out a series of analysis,including tensile,impact toughness and hardness tests for base metal and welded joint,combined with metallographic analysis,integrated assessment for microstructure and properties of steel was conducted.The results showed that the ensile strength of SAWL pipe welded joints is close to that of base metal,the microhardness of weld metal is higher than that of base metal,and the micro-hardness in HAZ is lower than that of base metal.The submerged arc weld metal is with good toughness,the ductile-brittle transition temperature is-60～-50 ℃,and the ductile-brittle transition temperature in HAZ is-30～-20 ℃.

According to the welding procedures and heat characteristics of the submerged arc welding,the geometric model and finite element model of submerged arc welding was established by ANSYS software.The temperature field of X80 pipeline steel was simulated.The welding process parameters are I=1500A、U=33 V、v=1.7 m/min,the welding heat source model chooses the double ellipsoid model.Appliing to moving load by APDL procedures,the fusion shape,size and temperature distribution of heat affected zone were calculated.The simulation results are in agreement the experimental results.

The coiled tubing ring seam 3D welding temperature field numerical analysis model was set up by finite element software ANSYS.The double ellipsoid heat source distribution model was imported,and the corresponding APDL programs were developed.The backing welding temperature field curve was calculated.The simulation results are basically consistent with experiment results,which show that the method can accurately calculate the welding temperature field.

随着直缝埋弧焊钢管需求的不断加大,分析和研究直缝埋弧焊管各项性能指标显得尤为重要.本研究对国外某钢厂生产的X100直缝埋弧焊管进行了一系列分析,对母材和焊接接头进行了拉伸、冲击韧性和显微硬度等试验,结合金相组织分析,综合评定该钢组织性能.结果表明,直缝埋弧焊管焊接接头抗拉强度接近母材,焊缝金属的显微硬度高于母材,热影响区显微硬度低于母材；埋弧焊焊缝金属的韧性良好,韧脆转变温度为-60～-50℃,热影响区韧脆转变温度为-30～-20℃.

In drilling process, drill bit breaks the rock into cuttings of different sizes and shape that accumulate at the bottom of a well. Bits may be broken repeatedly if the cuttings could not be cleaned up on time, and thus affect drilling rate and increase drilling cost. In high angle deviated well and extended reach well, cuttings are easily to build up cutting bed, leading to pump building, bit bouncing and drill pipe sticking. Borehole cleaning is therefore a key technique for drilling of high angle deviated well. This paper detailed the danger of cutting bed and processing, analyzed the factors affecting hole angle, velocity in annular, drilling fluid performance, flow state of drilling fluid, and rotation of drilling tool, and put forward some effective methods to solve the cutting migration in high challenge directional wells. It pointed out that the most effective method to clean cuttings away was to be based on moderate use of large-displacement tools, improvement of drilling fluid performance, and with the help of the tools removing cuttings bed.

Through the analysis on the composition,properties and weldability of grade D36,the welding method and technological measures of lifting joint structure are determined.In addition,through weld procedure qualification,the optimized welding process is electrode arc welding for backing welding and CO2 gas protect flux-cored wire welding for filling and covering welding and the heat input is 2.8 kJ/mm,2.5 kJ/mm and 2.3 kJ/mm respectively.Welding materials,preheating conditions,preheating temperature are also determined.The results in field production show this optimized process is reasonable and reliable.

Wellbore temperature is significant to well program and safety drilling for deep water drilling operations. On the basis of transient heat transfer mechanisms involved in deep water drilling among wellbore and formation and sea water, wellbore temperature profile, especially near sea bed and sensitivities to drilling fluid circulating duration, inlet temperature, water depth, water temperature, riser insulation and drilling fluid specific heat capacity have been analyzed via this model. Analysis show that deep-water wellbore temperature is much lower than a land well, the temperatures above sea bed normally ranges 10-30°C, and decreases with increased circulating duration; temperature at both outlet and bottom hole decreases drastically with increased water depth, and heat generation must be considered into estimating wellbore temperature profile especially one at bottom hole.