高时效金刚石钻头的研究现状

在金刚石钻头应用研究过程中,高效率与长寿命经常是互相矛盾的,为协调两者的关系,研究者往往把如何提高钻进时效作为首要解决的问题.国内外学者对此进行了多方面的研究,如金刚石钻头人工出刃处理、优选金刚石参数、改变胎体耐磨性,以及研制出各种异形唇面钻头和弱包镶金刚石钻头.     

金刚石钻头钻进过程中摩擦磨损性能研究现状

金刚石钻头钻进破碎岩石的过程是一个钻头表面与岩石表面相互接触相互运动的过程,钻头破碎岩石的同时,必然因岩石的反作用而发生磨损.研究表明,该过程进行中,金刚石可能出现不同的磨损形态,这些形态出现的比例直接影响着钻头的使用情况.因此,根据不同胎体性能的钻头钻进不同岩性地层后的形貌观测,结合金刚石出刃状况,进一步研究分析金刚...     

老挝纳勐铜多金属矿区坚硬“打滑”地层钻进方法

在老挝纳勐铜多金属矿区存在一层坚硬致密的弱研磨性的"打滑"地层,钻头消耗极大,钻进效率极低,严重影响了施工进度。文章结合项目的生产实际情况,对钻进参数进行优化,选取适宜于该地层的金刚石钻头进行钻进试验,经过实践验证,大大提高了钻进效率,在该地层取得了良好的应用效果。总结了生产实践中取得的成功经验,对以后在该类型地层进行钻探施工,可以起到很好的指导作用。     

适合于石油钻井地层岩石研磨性测定的标准磨损件研制

为了准确地测定石油钻井地层岩石的研磨性,设计了一种标准磨损件,通过室内试验,研究了不同胎体配方及金刚石参数对试件钻进深度和磨损量的影响规律,优化了试件配方参数。标准磨损件设计为微型取心钻头结构,以酚醛树脂和铜粉为胎体主要材料,以金刚石为磨削元件,采用热压工艺烧结合成,标准试件的磨损能够反映金刚石钻头的磨损实质。以标准试件研磨破碎单位体积岩石的磨损体积作为岩石研磨性指标,试验测定了石油钻井地层代表性岩石的研磨性指标,将石油钻井地层岩石的研磨性分为6级。结果表明:标准磨损件的金刚石体积分数为25%、粒度为60目,胎体配方为:酚醛树脂55%、Cu25%、Cr2O38%、ZnO6%、SiC5%、空隙1%。     

孕镶金刚石钻头的设计和使用

本文通过介绍国外硬、软胎体金刚石钻头的使用情况，提出了设计与使用孕镶金刚石钻头过程中一些值得注意的问题。     

人造金刚石在建筑施工中的应用

阐述了人造金刚石的基本性能和在建筑施工中的作用，分析了热压烧结对金刚石强度的影响，薄壁金刚石钻头对胎体的耐磨性、强度、冲击韧性、合金组分与金刚石在高温热结时的关系进行了探讨，并做了生产试验，取得良好的使用效果。     

润渭冲洗液对胎体材料的润滑作用

本文用试验的方法证实了润滑剂对胎体的润滑性是影响金刚石制品工作效率与寿命的一个重要因素，并得出结论：钻进硬岩时，润滑剂应对胎体的润滑性较差，以保证新金刚石不断出露、提高时效；而钻进研磨性较大的岩层时，所用润滑剂对胎体的润滑性应较好，以减少胎体的磨损达到提高寿命的目的。根据以上结论本文提出了一种新型、高效润滑剂—Ｓ－１型润滑剂，并在室内进行了试验，证实了Ｓ－１型润滑剂有明显提高时效的作用。     

电镀薄壁金刚石钻头性能的试验研究

本文研究了电镀薄壁金刚石钻头胎体性能和胎体与钢体间的结合强度。试验结果表明：电镀薄壁金刚石钻头钻孔速度快，成本低，有较好的经济和社会效益。     

孕镶齿切削效率数值模拟及实验研究孕镶齿切削效率数值模拟及实验研究

PDC钻头和牙轮钻头在深部难钻地层中钻进时出现钻头钻进效率低、磨损速度快、寿命短等现象,相对而言,孕镶金刚石钻头凭借其特殊的破岩机理和“自锐性”在此类地层中具有良好的钻进性能,已成为提高深部难钻地层破岩效率的重要手段之一。本文以金刚石浓度、粒度、钻压、转速与孕镶齿的切削效率内在影响规律研究为目的,利用离散元软件PFC3D建立孕镶齿磨削砂岩的物理模型来进行数值模拟,然后进行孕镶齿磨削实验,实验数据与模拟结果的对比,验证了孕镶齿选取平行黏结模型来进行模型建立及仿真的正确性,从而粒度、钻压、转速、浓度对切削效率的影响逐渐降低,同时为孕镶钻头工作性能分析、个性化设计、地层适应性评价及钻头选型提供了依据。     

真空中频热压在金刚石制品的应用研究

本文介绍了一种制造金刚石钻头的工艺，该工艺是在热压基础上，应用了真空技术，彻底改变了热压烧结气氛，使动力真空系统与升温，加压过程有机地联系起来，其本身特点是：烧结体在真空条件下施加高温和机械压力，使烧结过程产生了脱氧，排除杂质，净化与活化烧结等作用。所制造的金刚石钻头，可以明显地提高金刚石高温热稳定性，提高胎体综合性能和对刚石的包镶能力。     

Drilling detritus and the operating parameters of thermally stable PDC core bits

A single rock type was drilled using two types of thermally stable polycrystalline diamond compact (PDC) and an impregnated diamond core bit using a fully instrumented laboratory drilling rig at a fixed rotational speed, and over a range of weights on bit (WOB). Operating parameters of the bits such as WOB, rate of penetration (ROP), rotational speed (RPM), torque and drilling specific energy (SE) were continuously monitored during the drilling trials. The effects of these parameters on the performance of the bits were examined. Relations between the drilling variables are also described. At each set WOB for each bit, the drilling detritus were collected. The detritus sizes between 1180 and 53 microns were analysed using wet sieving and sub 53 micron was analysed using a Malvern particle size machine. Both data were combined to obtain a particle size distribution at set WOBs for each bit. The relations between the particle size of the drilling detritus and operating parameters, cutter size and wear of the PDC and impregnated diamond core bits, and original rock grain size were established. An increase in WOB, ROP, wear rates, pins or diamond size increased the drilling detritus size for the bits. No relation was found between the drilling detritus and the rock grain size due to the regrinding effect and the high proportion (> 30%) of matrix material in the rock.     

坚硬地层金刚石钻进参数的选择

针对坚硬地层金刚石钻进参数的选择问题，从钻压、转速与泵量三方面作了分析，提出了合理选择钻进参数的方法，以保证正常生产施工的需要，提高钻探进尺效率。     

弱风化硬岩中大口径旋挖钻机钻进新工艺实例分析

对旋挖钻机在硬岩(如弱风化砂岩、灰岩)地层中进行大口径钻进的方法进行了研究。设计了筒式和螺旋式两种截齿钻头,创新并应用了以截齿钻头为主的多钻头组合工艺方法。工程实践证明,这些方法成功地解决了上述条件下弱风化硬岩中大口径钻进的难题。     

单牙轮钻头井底切削仿真分析

单牙轮钻头在小井眼钻井中具有良好的经济效益 ,本文通过在单牙轮钻头上分别建立钻头坐标系、牙轮坐标系及牙齿坐标系 ,建立起单牙轮钻头井底切削仿真模型。用计算机绘制出反映单牙轮钻头结构参数和钻井参数的井底轨迹和井壁刮痕 ,对单牙轮钻头的设计和钻井参数选取具有重要意义。     

Use of digital image processing techniques for evaluating wear of cemented carbide bits in rotary drilling

This paper presents the use of image processing techniques in monitoring of bit wear, especially, WC/Co cemented carbide bits that are commonly used in rotary drilling in mining, civil and petroleum engineering. Image of the bits was acquired using a CCD camera. The background was subtracted from the image to reduce noise effects. A Laplacian filter has been used to enhance edge contrasts. Structural elements have been applied to dilate, erode and close boundary edges. Edge detecting was conducted using a canny edge detector. Image processing approaches; first order surface metrics, gray level co-occurrence matrix (GLCM) based texture analysis and minimum distance based classifiers have been used to estimate wear of tricone drill bits in rock drilling. A digital balance was used to obtain weight loss of the bits and also wear of their heel row and gage row (dimension loss) was measured using a micrometer in different directions. Results showed that, of the surface metrics, bit area and major length axis could be good measures for bit wear estimation. The entropy and contrast features of the GLCM method showed good correlations with bit weight loss. Of the minimum distance based classifiers just Euclidean, City block and Chebychev distances had reliable correlations with weight loss and heel row wear rather than other features.     

Analysis of steering in horizontal directional drilling installations using down-hole motors

Horizontal directional drilling is becoming an increasingly popular technique for the installation of pipes in urbanised environments or in locations where trenching is difficult, such as under rivers or railways. This technique utilises down-hole bits to create the bore before it is expanded with back-reamers to allow installation of the product pipe. Controlling the path of the bore is critical to the success of many horizontal directional drilling installations and the potential inability to maintain such positional control is a factor that prevents the widespread adoption of this technique in place of traditional open cut methods.Two types of drill bit are commonly used in horizontal directional drilling; shaped jet-cutting bits and bits mounted on bent-subs and driven by mud-motors, the former being utilised in weak ground conditions and the latter in stronger formations. This paper analyses a dataset of survey data from pilot bores for fifty-four HDD installations that used mud-motors to investigate the parameters that impact upon the control of the position of the drilling bit. The drives are broken down into sections of rotary and slide drilled borepath and these are investigated separately. Drilling practice, drilling equipment, length of drive and the geology in which the bore is being established will have an effect upon the ability to control the position of the drilling bit.     

卵石层金刚石钻进技术

介绍卵石层采用金刚石钻进的成功经验,提出了卵石层金刚石钻进技术,论述了卵石层结构特征及金刚石钻进的可行性。该钻进技术在工程勘察中可以推广应用。