PDC实钻性能的测试与评价

在总结分析国内外有关PDC切削齿性能测试方法的基础上,采用常规检测方法对不同生产厂家的5种PDC产品的磨耗比、冲击韧性和热稳定性进行测试、评价和优选,并对优选出的2种PDC在微钻试验平台上进行实钻性能测试。结果表明:用微钻试验的钻进效率衰减系数和钻进效率均峰值来评价PDC实钻性能,方法科学,数据准确,结果实用,可作为煤矿用PDC钻头切削齿选型的参考依据。      

X射线衍射测试PDC表面残余应力的实验研究

作者采用DIMAX2500型X射线衍射仪,通过对入射光狭缝尺寸进行调整,使X射线的照射光斑尺寸缩小为1.5×5 mm,从而实现了对PDC表面沿径向的四个不同位置的应力测量.测量采用sin2ψ法,不但测出了PDC表面不同位置的残余应力,还由此得到了PDC表面应力沿径向的分布规律,而且这一测试结果与通过有限元分析计算出的应力分布趋势基本吻合.作者还对测试值与有限元分析计算值出现偏差的原因从测试方法、有限元分析参数取值及样品表面加工方式等几方面进行了分析讨论.     

对金刚石复合片的自锐性、耐磨性、抗冲击韧性测试的探讨

本对测试金刚石复合片(简称PDC片)的自锐性、耐磨性、抗冲击韧性的方法进行了探讨。本方法采用自制的台架测试装置对PDC片的性能进行测试，并对该测试装置的原理、结构、测试方法及测试情况作一介绍。     

界面结构对PDC抗冲击性能的影响

本文采用重陀倾斜式方法测试了不同界面结构的PDC的抗冲击韧性,并对PDC冲击破坏机理进行了讨论,对界面结构以及其它因素对PDC抗冲击性能的影响进行了探讨和研究.结果表明:重陀倾斜式方法能够较好地反应PDC钻头工作时的实际受力情况;在同一工艺参数下,PDC层与硬质合金基体之间的界面结构对PDC的抗冲击性能影响很大;随着界...     

石油天然气钻采用PDC切削齿的最新发展

本文介绍了近年来PDC钻头的设计理念和PDC切削齿的最新技术动向,PDC切削齿的若干关键技术,以及国际上最新采用的测试技术。通过提高金刚石含量,加强D-D键结合,优化界面几何形状,减少内应力,精细控制各种原辅材料的质量,最终提高PDC切削齿的综合性能。文中介绍了PDC超声波逐行扫描探伤技术,最新的重负荷检测耐磨性能,以及耐热性和抗冲击性的检测技术。最后还对石油钻井市场现状进行了介绍。     

基于热性能分析的PDC切削齿选型试验研究

为提高PDC切削齿选型的可靠性,从热性能角度出发,分别对不同厂家的PDC切削齿进行常温激光拉曼、高温激光拉曼及热重等分析,并结合其高温磨耗比测试,分析PDC切削齿的残余应力、石墨化转变、热稳定性以及高温耐磨性等,综合评价不同厂家的PDC切削齿性能;同时,制作?94 mm四翼弧角PDC钻头并进行现场钻进试验.结果表明:现...     

PDC钻头浸渍工艺评定研究

为了评定PDC钻头胎体的烧结浸渍工艺,设计了16只以不同的烧结温度和保温时间制造的PDC钻头,对钻头试样的烧结浸渍胎体进行了力学性能测试和组织结构金相显微分析,结合试验结果,分析了烧结温度和保温时间对PDC钻头浸渍工艺的影响。试验结果表明:采用烧结温度为1 180℃和保温时间为95 min时胎体试样的各项测试结果均达到最优,其具体力学性能参数为平均硬度HRC 47.33,平均冲击韧性9.20 J,平均抗弯强度593.33 MPa,其显微组织均匀,结构完整。     

钻探用聚晶金刚石复合片的显微组织及性能

采用上层为细粒度金刚石、下层与硬质合金接触的为粗细度金刚石的分层设计理念，制备钻探用多金刚石层的聚晶金刚石复合片（PDC），对比不同粒度的单层金刚石PDC与多层金刚石PDC的显微组织与性能的差异。利用超声波扫描、扫描电子显微镜（SEM）表征每种PDC的内部缺陷和表面形貌等，并分别对PDC的耐热性、抗冲击性和耐磨性进行测试。结果表明：多层金刚石PDC的综合性能良好，其表层耐磨，下层更耐冲击，且其具有更加均衡的耐热性、抗冲击性和耐磨性。细粒度金刚石层PDC的耐磨性更高，但耐热性和抗冲击性较低，而粗粒度金刚石层PDC的耐热性和抗冲击性能更好，但耐磨性较差。     

聚晶金刚石复合片无损检测方法的探讨

本文在分析聚晶金刚石复合片（PDC）无损检测技术（NDT）的基础上,针对POC复合片的主要缺陷,探讨了利用便携式超声波探伤仪对PDC进行无损检测的可能性。得出了实验条件下PDC分层、裂纹缺陷的超声波测试波形图和主要技术参数如下。工作方式：单探头（单一发射,强度不变）;检波方式：双波;频段：中等;声压：2dB。扫描量程：10mm;脉冲移动位置：8．82mm。实验结果表明：本方法对PDC的分层、裂纹等缺陷有明显的特征反应。     

PDC钻头焊接工艺的研究

聚晶金刚石复合片(PDC)钻头钻进的岩层越来越复杂,在复杂地层及硬岩钻进中时有掉齿、崩刃等现象发生,造成钻头失效.研究表明,焊接工艺是影响PDC钻头的最主要原因.本文以φ94 mm三翼内凹式PDC钻头体为试验样品,对影响PDC钻头焊接质量的主要因素进行了分析,研发出一种新的PDC钻头焊接工艺.试验结果表明:采用该工艺制...     

PDC抗冲击性能测试及测定仪的研制

本文在研究分析现有ＰＤＣ抗冲击性能测试方法的基础上，模拟ＰＤＣ在钻井过程中的实际受力状态，研制出了ＤＦＺＹ型ＰＤＣ抗冲击性能测定仪，并对仪器进行了可靠性验证及实测试验，取得了满意的效果。     

Tribocorrosion properties of polycrystalline diamond compact in saline environment

Tribocorrosion properties of polycrystalline diamond compact (PDC) in solution containing sodium chloride were investigated using a modified pin-on-disc wear test rig. Tests were conducted at various salinities (0–20%) for a better understanding of the abrasion-corrosion interaction. The corrosion behavior was examined through a three-electrode electrochemical cell. The contributions of pure abrasion and pure corrosion as well as their synergy to the total volume loss were calculated. The influence of cathodic protection on the abrasion-corrosion performance of PDC was also evaluated. Experimental data in this paper shows that the PDC suffers more severe damage as the sodium chloride concentration increases gradually and the applied potential of −1.0 V vs. SCE can suppress the corrosion-related effects to a negligible level. Both electrochemical measurements and SEM micrographs of worn surfaces were used to detail the degradation mechanism. Despite the fact that it is the mechanical wear that dominates the abrasion-corrosion mechanism, results reveal that the interaction between the abrasion and corrosion plays a significant role. Moreover, an effective volume calculation method based on three dimensional point cloud was proposed to determine the wear volume of PDC. Validation studies demonstrate that the measurement method is feasible and accurate with an error of no more than 5%.     

PDC磨耗比检测中称重问题的探讨

本文简要介绍了在金刚石复合片(PDC)磨耗比检测过程中一个应注意的重要问题：就是如何对PDC进行准确地称量以减少检测过程中产生的误差，并提出一些解决问题的思路。     

适合吐哈油田西山窑地层的PDC钻头提速研究

吐哈油田西山窑地层具有高硬度、研磨性强等特点。该地层采用过多种PDC钻头,但机械钻速提高不甚明显,为此,研究分析了PDC切削齿磨损对机械钻速的影响,提出了以加强PDC钻头的耐磨性为目标来提高机械钻速的设计观点,对PDC钻头的冠部形状、切削齿尺寸、切削齿排布、切削齿工作角等进行优化设计,设计的钻头在吐哈核3井进行了钻井试验。结果表明：设计的新钻头机械钻速与使用过的两种PDC钻头相比分别提高了29%和92.5%,且钻头钻时60 min以上时,有轻微磨损,仍可继续使用。     

聚晶金刚石复合片脱Co增强性能研究

在制备普通聚晶金刚石复合片（PDC）的基础上,将一次合成的聚晶金刚石进行脱Co处理,再重新组装进行二次合成。新合成PDC的耐磨性、抗冲击性能和耐热性等有很大提高,其平均体积磨耗比达到5.20×106,比普通产品的磨耗比高约40%;金刚石层中Co的减少并未造成其抗冲击性能的下降;耐热性能也大幅度提高。脱Co处理能有效减少金刚石层中的Co含量,并改善其结合剂分布的均匀性,抑制结合剂的局部聚积,最终使金刚石层中D-D键数量明显增多,PDC的耐磨性提高。      

Effect of cobalt content on the performance of polycrystalline diamond compacts

Cobalt was an indispensable role in the damage of a PDC cutter due to its inevitable adverse thermal effect like thermal catalysis, thermal expansion and thermal oxidation in the welding and drilling process, while the quantitative studies on its serial thermal damage effect were still seldom reported. In order to understand the damage mechanism of a PDC cutter and therefore design better products, it was quite necessary to study the roles of cobalt in the PDC cutter by a quantitative means. In present study, the total cobalt content of the PCD layer of polycrystalline diamond compacts were adjusted by blending different amount of microsized cobalt powder in the mixed diamond grains and the infiltrated cobalt from the cemented carbide cylinder during the HTHP sintering process. The sintered PDC cutters were examined by XRD, SEM, EDX, vertical lathe tests, and impact tests, and it was found that the abrasive ratios of the fabricated PDC cutters were strongly dependent on the cobalt content of sintered diamond layers. The PDC cutter without adding cobalt powder exhibited the best resistance to the abrasion, while the PDC cutters sintered by adding 4% mass of cobalt powder demonstrated the worst abrasive ratio, which was the direct proof confirming that by decreasing the content of residual cobalt in the PCD layer the resistance of the PDC cutter to the abrasion would be improved significantly. A non-destructive characterization method was adopted based on the statistical calculation was proposed by using Matlab and Image-J software to quantitatively explore the relationship between the cobalt content as well as the average size of residual cobalt in the PCD layer and the abrasion performance, which opened a new technical route for the disclosure of cobalt-dependent abrasion resistance for the PDC cutter analysis. Moreover, a cobalt-rich narrow zone was found to appear in the interface of PCD/cemented carbide, which was deduced to be the main reason to cause the delamination of PCD layer from the cemented carbide. It was also interesting to find that the percentage of added cobalt powders seemed no adverse effect on the impact performance of the PDC cutters. The conclusion of present study about the cobalt role in the PDC performance was quite good for understanding the PDC damage modes and helped for the better design and fabrication of PDC.     

Polycrystalline diamond cutting element control using high frequency C-scan image processing

The quality control of drilling tools used in the oil industry essentially consists of testing the cutting elements distributed around the petroleum tool. This study presents a nondestructive testing (NDT) method for the detection of different kinds of defects inside polycrystalline diamond cuttine elements (PDC). This ultrasonic method, based on high frequency (100 MHz) C-scan image processing, allows the detection of three major types of defect such as diamond layer debonding from the substrate, cracks and thermal defects of the diamond layers. These defects induce a perfectly quantified behaviour to mechanical abrasion resistance and fatigue tests. Experimental results show good correlation between our ultrasonic measurements and classical abrasion resistance tests. In fact, a PDC sample exhibiting defects detected by the C-scan technique has been submitted to a mechanical fatigue process and optical microscopic analysis. These tests have shown that each kind of defect has an influence on one or more mechanical characteristics. Using C-mode scanning acoustic microscopy (with a 50 μm pixel size), allows an extremely precise and quantified level of erosion resistance of the cutting elements without systematic resort to expensive destructive tests carried out during the reception of the batch. The rejection of samples showing harmful defects will eliminate the erratic and sometimes unexplained destruction of some tools which were considered to be defect-free.     

基于单片机测试系统对凿削磨损的动态测量和分析

介绍了单颗粒凿削磨损测试系统的原理、结构、测试方法以及在镁合金表面电弧喷涂锌铝合金的表面质量的检测中的应用.试验通过对试样划痕形貌尺寸数据的测量和对单片机力学信号的采集来进行计算,从而来绘制多条比能耗对应磨损体积的关系曲线,从对凿削磨损的开始到结束的整个磨损过程的动态分析,为磨损机理研究提供更多的细节,通过测试数据的处理,继而确定获得具有最佳耐磨性能的喷涂工艺参数.     

金刚石-硬质合金复合片的耐磨性测试方法研究

金刚石-硬质合金复合片的耐磨性是一个非常重要的技术指标,但迄今为止国际上尚无统一的PDC耐磨性测试标准。本文在分析我国和乌克兰评价PDC耐磨性方法优缺点的基础上进行了对比性研究,指出乌克兰超硬材料研究所按复合片在实验台上切削岩块的磨损高度和面积来评价的方法,更接近于孔底岩石破碎过程,PDC的几何磨耗量可更全面真实地反映复合片在钻探生产中的工作寿命。同时,讨论了乌克兰方法需要完善的地方。