Two-Layer Contact Nonlinear Mechanical Analysis of Flexible Drilling Tool in the Wellbore

The lack of research on flexible drilling tool leads to limited application of ultra-short radius horizontal wells.The flexible drilling tool is different from the conventional drilling tool.The flexible drilling pipe involves a mutual transition between the structure and the mechanism during the deformation process.At the same time,the flexible drilling pipe and the eccentric guide tube,the guide tube and the wellbore generate random contact.In this paper,3-D beam elements,universal joint elements,rigid beam elements and the beam-beam contact elements are combined to establish a two-layer contact nonlinear finite element model of the flexible drilling tool in the wellbore.The dynamic relaxation method is introduced for numerical solution.The feasibility of the model and the algorithm is verified by an example.The mechanical analysis of flexible drilling tool under the four hole inclinations in the oblique section is carried out.It is found that the flexible drilling pipe has a“folded line”deformation.The contact force between the flexible drilling pipe and the guide tube is randomly distributed.The contact force between the guide tube and the wellbore in the oblique section is greater than that in the vertical section.As the hole inclinations increase,the torque and axial force transmitted to the drill bit gradually decrease.

Numerical simulation of rock-breaking and influence laws of dynamic load parameters during axial-torsional coupled impact drilling with a single PDC cutter

Axial and torsional impact drilling technology is used to improve the drilling efficiency of hard rock formation in the deep underground.Still,the corresponding theory is not mature,and there are few correlative research reports on the rock-breaking mechanism of axial and torsional coupled impact drilling tools.Considering the influence of the impact hammer geometry and movement on the dynamic load parameters(i.e.,wavelength,amplitude,frequency,and phase difference),a numerical model that includes a hard formation and single polycrystalline diamond compact cutter was established.The Riedel-Hiermaier-Thoma model,which considers the dynamic damage and strength behavior of rocks,was adopted to analyze the rock damage under axial and torsional impact loads.The numerical simu-lation results were verified by the experimental results.It was found that compared with conventional drilling,the penetration depths of axial,torsional,and axial-torsional coupled impact drilling increased by 31.3%,5.6%,and 34.7%,respectively.Increasing the wavelength and amplitude of the axial impact stress wave improved the penetration depth.When the bit rotation speed remained unchanged,increasing the frequency in the axial and circumferential directions had little effect on the penetration depth.However,as the frequency increased,the cutting surface became increasingly smooth,which reduced the occurrence of bit vibration.When the phase difference between the axial and circumfer-ential stress waves was 25%,the penetration depth significantly increased.In addition,the bit vibration problem can be effectively reduced.Finally,the adjustment of engineering and tool structure parameters is proposed to optimize the efficiency of the axial-torsional coupled impact drilling tool.

万米深井上部大尺寸井眼钻柱动力学特性研究

油气勘探已向更深、更复杂的超深层的万米勘探新领域推进,但上部大尺寸井眼给万米深井的钻井提出了巨大挑战:岩石硬和返速低导致钻速慢,大尺寸井眼内剧烈振动导致钻具裂纹多发,钻压小则钻速慢,钻压稍大则下部振动快速加剧从而导致大尺寸钻具使用寿命远低于预期。为此,在对比研究了深地川科1井(以下简称SDCK-1井)和毗邻8000 m超深井上部井段钻柱振动问题基础上,基于全井钻柱系统动力学模型和数值仿真方法,针对性研究了大尺寸井眼中的钻柱动力学特性。研究结果表明:①井眼尺寸越大,钻头和下部钻具的振动越剧烈,SDCK-1井二开大尺寸井眼与邻井中等尺寸井眼相比(井深500 m处),其钻头及下部钻具振动强度均值分别增加了48.0%和41.5%,比SDCK-1井三开中等尺寸3000 m井深的钻头及下部钻具振动强度均值分别高了29.0%和2.9%;②相同井眼尺寸和岩石特性情况下,下部钻具组合比钻柱整体长度对钻头振动的影响更大,优化下部钻具组合能够明显改善钻头振动,保护钻头,同时还可以提高钻头破岩能量利用效率实现钻井提速;③在大尺寸井眼中钻头破岩激励向上传播,横向振动衰减慢于轴向振动衰减,大尺寸钻头扭矩更大且钻压和扭矩波动更加明显,因此从保护下部钻具的角度出发,大尺寸井眼钻具组合对抑制横振更加有效;④大尺寸井眼中下部钻具弯矩和弯矩波动更大,现场频繁出现的钻具裂纹除受控于整体振动强度较大以外,交变弯矩是裂纹发生的重要原因。结论认为,该研究成果揭示了超深井大尺寸井眼中钻柱的动力学特性,指出了应着重控制横振和交变弯矩,该认识可以为超深井上部大尺寸井眼钻井提供技术指导。

Tillage Effect and Development Prospect of Fenlong Farming Tools with"Drill"

In this paper,farming and crop cultivation effects of farming tools with"drill"which are invented independently in China are clarified firstly,containing horizontal cutting of soil,super deep ploughing,deep loosening and not disturbing soil layer,granular soil,soil not easy to bond and harden,and one-time land preparation.It is a significant path to deeply develop and use the"five natural resources"not fully utilized by human beings(soil resources at plough bottom and below,saline-alkali land,natural rainfall,solar energy,oxygen)and realize"mitigation"of five natural disasters(flood,drought,high temperature,low temperature and climate warming).In the past 10 years,the farming tools have been applied in 40 kinds of crops in 26 provinces of China.Compared with vertical breaking of soil by traditional"plow",the amount of loose soil,water storage and dissolved oxygen in cultivated land increased by more than one time,and yield increased by 10%-50%.They have been applied in transformation of saline-alkali land in 10 provinces,and yield increased by 30%-150%.After Fenlong treatment for 1 and 2 years,biomass of sugarcane increased by 68.9%and 50.1%respectively.Net photosynthetic rates of Gramineous crops were improved by 6.82%-11.94%,while net photosynthetic rates of Legume crops were improved by 20.32%-32.08%.After"spiral drill","vertical two-knife drill","vertical three-knife drill"and other hollow series of Fenlong farming toolss were invented newly.They were the most advanced farming tools with large soil discharge and small resistance,and could be equipped in large-,medium-and small-size modern Fenlong agricultural machinery as key technology,thereby setting up a new"standard stalk"for world agricultural reform and bringing benefit to mankind.

煤矿防冲钻孔机器人全自主钻进系统关键技术

针对高地应力矿井钻孔卸压作业智能化程度低的技术难题,总结分析了国内外钻孔卸压技术和装备的研究现状,指出研发高性能、高可靠、高效率的防冲钻孔机器人全自主钻进系统是破解冲击地压防治难题的重要发展方向。为此,凝练了影响钻进系统性能的“孔位精准识别、钻具姿态精确感知、无线电磁随钻智能检测、钻具运行状态智能识别和钻进系统精确控制”五大关键技术,并给出了解决思路和方法。针对在复杂恶劣环境下卸压孔的精确识别问题,设计了融合图像尺寸调节和多阶段训练模式的卸压孔图像样本扩充SinGAN模型,引入多层特征融合优化的FasterRCNN,构建了基于改进SqueezeNet轻量级网络架构的孔位识别模型,以实现卸压孔位的准确快速识别;针对钻具姿态精确感知问题,提出了基于改进梯度下降法算法优化无迹卡尔曼滤波的惯性测量单元(Inertial Measurement Unit,IMU)初始对准方法,设计了多个IMU的空间阵列布局方式,研究了基于BP神经网络的钻具姿态误差补偿方法,旨在提高钻具姿态的解算精度,实现精准钻孔卸压;针对复杂地质环境下钻进工况的精确检测问题,搭建了煤矿井下随钻测量无线电磁传输系统架构,探讨了微弱电磁波信号自适应调制和随钻高速双向电磁传输技术原理,研究了孔底地质参数、几何参数和工程参数的测量原理和实现过程;针对钻进系统运行状态识别问题,构建了钻进信号时域、频域、时频域的多域特征和深度网络高级特征提取架构,提出了钻进系统关键零部件健康状态评估和故障诊断技术,构建了基于改进蝙蝠优化长短期记忆网络的卡钻风险因子预测模型,实现对卸压钻具卡钻状态的准确预测;针对钻进系统的精确控制问题,分析了钻进系统的液压系统工作原理,构建了考虑煤岩性状的钻进系统精确控制方案,探讨了基于转矩和位置的钻进系统最优控制参数求解原理,旨在实现钻进回转系统和给进系统的智能协同控制和并行作业。

Design and Fluid-Dynamic Analysis of a Flushing Nozzle for Drilling Applications

The actuator is a key component of the creaming tool in drilling applications.Its jet performances determine the effective reaming efficiency.In this work,a new selective reaming tool is proposed and the RNG k-εturbulence model is used to calculate its internal and externalflowfields.In particular,special attention is paid to the design of theflushing nozzle.The results show that the jet originating from theflushing nozzle has a significant influence on rock cutting and blade cooling effects.In turn,the jet performances depend on geometric structure of the creaming actuator.In this framework,a conical-cylindrical nozzle with a diameter of 7 mm is initially considered as a basis to implement a strategy to optimize the structural parameters of the reaming actuator,and improve the related side tracking reconstruction technology.

Analysis of Tool Wear Rate in Drilling Operation using Scanning Electron Microscope (SEM)

Hole making had long been recognized as the most prominent machining process, requiring specialized techniques to achieve optimum cutting condition. Drilling can be described as a process where a multi-point tool is used to remove unwanted materials to produce a desired hole. It broadly covers those methods used for producing cylindrical holes in the work piece. However, high production machining and drilling with high cutting velocity, feed and depth of cut is inherently associated with generation of large amount of heat and high cutting temperature. Such high cutting temperature not only reduces dimensional accuracy and tool life but also impairs the surface integrity of the product. In this case, high pressure coolant (HPC) is very effective to reduce temperature. When temperature is increased a large amount of tool wear appears at the drill bit. In this situation, high temperature either affects roundness of the hole or chip shape and color of chip. HPC is applied in the same direction as the drill bit. HPC has reduced temperature as well as improving roundness and also provide lubrication in the tool tip and surface interface.

SDTK1井钻铤接头二次上扣特性分析与井下等效冲击扭矩预测

基于8"(203.2mm)钻铤接头三维弹塑性有限元模型,分析复杂载荷条件下NC56钻铤接头内、外螺纹的受力特征和井下二次上扣特性,通过有限元分析,根据接头内、外螺纹台肩处相对偏移量计算井下等效冲击扭矩,形成井下等效冲击扭矩的预测模型,利用塔里木盆地GT1井井下实测结果验证该模型正确性,并应用于中国第1口超万米特深井——深地塔科1井(SDTK1井)。结果表明:复杂载荷作用下钻铤接头应力分布不均匀,台肩处和靠近台肩的螺纹牙处vonMises应力水平相对较高;对于按API(美国石油学会)标准上扣的203.2mm钻铤接头,当井下等效冲击扭矩超过65 kN·m时,钻铤接头的上扣预紧平衡被打破,钻铤接头发生二次上扣;随井下等效冲击扭矩的增大,内、外螺纹台肩处相对偏移量增加。SDTK1井井下存在较大冲击扭矩,井下载荷环境复杂,需要采用双台肩钻铤接头以提高接头的抗冲击扭矩能力或优化作业参数来降低井下冲击扭矩,从而有效防止钻具失效。

水平井尾管完井与钻井一体化设计控制技术

针对水平井尾管导向钻井技术存在的钻机旋转系统负载大、地面扭矩传动效率低、使用与维护成本高等问题,提出了水平井双管柱尾管差速旋转钻进新方法,揭示了相应的技术原理,设计了双管柱差速旋转传动、复合旋转导向及悬挂器等井下专用工具,优化了相关工艺流程;提出了导向钻具组合工具面控制方法,建立了水平井双管柱尾管差速旋转钻进延伸极限计算模型。结果表明:水平井双管柱尾管差速旋转钻进技术配备常规随钻测量仪器和螺杆钻具,通过调节钻柱转速可以控制导向钻具组合的工具面,实现了水平井双管柱尾管差速旋转导向钻进;基于鄂尔多斯盆地东缘深部煤层气水平井工程案例计算水平井双管柱钻进延伸极限,与常规尾管钻井方式相比,采用双管柱尾管差速旋转钻进方式显著增大了水平井延伸极限,为水平井尾管完井与钻井一体化设计控制提供了参考。

BH-N型不提钻换钻头钻进技术研究与应用

地质钻探施工时起下钻更换钻头,需要占用大量时间,且存在一定的安全隐患,大大影响钻探效率,采用不提钻换钻头钻进技术可以很好的解决这个问题。以N规格绳索取心钻杆为使用平台,沿用BH-75钻具基本结构,并针对其存在问题,研制BH-N规格的不提钻换钻头钻具,同时根据N规格钻具的具体结构完善BH-75钻具,提高了钻具的承压能力和钻具收敛(投送)稳定性,增设了自动除沙机构等。在山东乳山金青顶金矿ZK43-1钻孔进行了现场应用,在孔深2081.20~2211.40米实现了不提钻换钻头,钻具岩心采取率达到100%,岩心质量好,最大限度减少起下钻次数,有效预防起下钻引发孔内事故。不提钻换钻头钻进技术为深孔地质勘探中钻进强研磨性、打滑、软硬频繁交替等地层,提供了及时优化钻头使用方案,降低能源消耗,有效的保护孔壁安全和减少劳动强度。

全旋转指向式导向钻井工具结构设计与仿真

为了提高全旋转指向式导向钻井工具的设计效率,缩短研发周期,笔者首先设计了该钻井工具的导向执行机构,简化导向执行机构的空间机构模型,通过自由度的计算,得出了该机构具有确定的运动。再对该钻井工具的结构组成和导向原理进行分析,得到了其导向控制方法是通过控制全旋转指向式导向钻井工具的双偏心环和旋转外套的角位移关系,调节其工具角和工具面角,实现导向钻井。最后利用SolidWorks和ADAMS软件对钻井工具虚拟样机进行三维实体建模及运动仿真,仿真结果表明该钻井工具可以实现工具面角(0~360)°和工具角(0~5)°的无级调节,验证了所设计的全旋转指向式导向钻井工具结构和导向原理的可行性,为原理样机的加工奠定了基础。

旋冲钻具凸轮-滚轮冲击机构工作特性分析

旋冲钻具能有效提高深层、硬地层的破岩效率,具有广阔的应用前景。凸轮-滚轮是实现冲击动作的关键机构,但复杂多变的井下环境导致机构损伤严重,进而影响破岩效率。基于旋冲钻具多井次的试钻数据,建立凸轮-滚轮动力学模型,通过显式动力学(Autodyn)分析不同冲程、转速、钻压下的工作特性,总结机构的形变特征提出优化方法。分析结果与试验数据和理论数值对比,验证了计算模型的准确性。结果表明:冲程增大可提高冲击效果,但高于10 mm冲程的滚子实际运动轨迹受钻速、滚轮尺寸、凸轮轮廓曲率影响其轨迹将变平缓。转速在9~18 rad/s时轴向加速度波动幅度较大,对钻具的稳定性具有一定影响。钻压增大凸轮内缘处形变特性明显,其形变量与钻压成正比,25 kN钻压下凸轮的形变量约是10 kN的2.6倍。凸轮齿顶、滚轮内缘处为易变形点,在齿顶处安装可换滚筒同时改变滚轮为鼓轮构型并对抛物线-直线-抛物线、2次多项式、摆线、7次多项式4类凸轮轮廓线型进行特性分析。选用摆线及7次多项式凸轮座轮廓和鼓轮可提高冲击效果,计算结果可为旋冲钻具设计提供参考依据。

冲击螺杆钻具结构设计与参数优化

为了高效钻进硬岩地层,将螺杆钻具的大扭矩与轴向冲击工具的高频低幅冲击特性相结合,研制了一种冲击螺杆钻具。在工具结构原理讨论的基础上,建立了轴向冲击短节的冲锤运动控制方程,分析了冲锤的运动特性,并以工具冲击功和最大能量利用率为评价指标,采用正交试验方法对主要工具结构参数进行了优化研究。研究结果表明:冲锤往复运动过程为加速度逐渐减小的非线性加速运动,节流喷嘴直径和冲锤运动行程是影响冲击功的主要因素,而冲锤质量、承压面积和腔体通孔面积是次要因素。节流喷嘴直径和冲锤承压面积是影响最大能量利用率的主要因素;而冲锤运动行程、冲锤质量和腔体通孔面积是次要因素。所得结论可为对冲击螺杆钻具的进一步优化设计和现场应用提供参考。

推靠式旋转导向系统钻具组合力学性能分析

针对基于动力学特性的旋转导向钻具安全性能研究较少。为此,综合考虑钻具结构、钻井参数、钻柱与井壁接触等参数,基于Lagrange方程建立了全井钻柱系统动力学模型,采用有限单元法对模型离散,并采用Newmark-β求解,根据旋转导向钻具结构和钻具属性,研究了扶正器安装位置、柔性节尺寸、钻压影响因素下的旋转导向钻具组合动力学特性和安全性能。研究结果显示:安装扶正器能显著降低旋转导向钻具组合的横向振动;柔性节的长度对旋转导向钻具组合的安全性能影响很大,合理的长度能显著降低横向振动,反之则会起到相反的效果;增加钻压会增加底部钻具组合的横向位移,工程上不建议在使用旋转导向工具时采用高钻压提高钻井速度。研究结论可为旋转导向工具研究和应用提供理论支撑。

胜利西部探区哈山地区组合钻井技术研究及应用

为解决胜利西部探区哈山地区中深层石炭系、二叠系坚硬地层可钻性差、地层倾角大、井斜难控制、井壁易失稳等技术难题,实现油气储量的高效勘探、效益开发,在现用常规钻井技术的基础上,通过分段组合钻井技术适用性研究与工艺优化,针对石炭系、二叠系的云质岩、火成岩难钻地层,提出气体钻井相关提速及安全施工配套技术,形成了地区施工规范;在气体钻井转钻井液施工后,优先选用“气体钻井+‘孕镶钻头+涡轮钻具/高速螺杆’”组合钻井技术,并针对地层特点研发了不同尺寸的高效孕镶钻头系列,实现井斜控制与机械钻速双提高。该组合钻井技术在哈山3和哈山2等井成功应用,取得了良好的效果,其中哈山3井气体钻井机械钻速达到5.2m/h,较常规钻井方式提速3倍以上,转钻井液施工后采用孕镶钻头+涡轮钻具/高速螺杆施工,地层倾角为30°,井斜控制良好,机械钻速接近1m/h,较常规钻井技术表现出良好的区域应用效果。现场应用表明,“气体钻井+‘孕镶钻头+涡轮钻具/高速螺杆’”组合钻井技术是实现胜利西部探区哈山地区中深层钻井提速提效的一种有效手段,但该组合钻井技术也存在瓶颈,结合对粒子冲击钻井技术的适用性研究,建议下步引进并完善粒子冲击钻井技术,力争实现区域钻井提速提效再突破。

顺北油气田二叠系火成岩钻井技术研究与应用

塔里木盆地顺北区块二叠系火成岩地层厚度大、硬度高、裂缝发育、非均质性强,导致机械钻速低与堵漏耗时长,相比邻区平均钻井周期增加达1.5倍。近几年,通过持续强化钻井液堵漏技术与优选高效钻井工艺,漏失量与堵漏时间逐步缩短,钻井指标逐年提高。本文分析了影响堵漏时间长与机械钻速低的主控因素,提出堵漏浆中加入竹纤维、变形颗粒以改善堵漏工艺技术,明确了冲击工具的适用条件,优选攻击性与抗冲击性的PDC钻头,改进混合钻头结构以及配套大扭矩、长寿命螺杆等技术对策,提速降本成效显著,为加快顺北油气田的高效勘探开发提供了指导。

螺杆钻具十字万向轴运动副球面磨损规律

螺杆钻具十字万向轴是传递扭矩和转速的关键结构,其运动副中锁紧轴与球座之间产生相对滑动而导致本体结构加速磨损,显著降低了万向轴的使用寿命。为研究锁紧轴与球座的圆弧面半径对滑动磨损的影响规律,建立多种圆弧面半径的三维磨损仿真物理模型;基于赫兹接触理论和Archard磨损理论研究不同半径条件下的体积磨损量、最大变形量、最大滑移距离和最大穿透深度的变化规律;借助现场试验进一步研究非密封十字万向轴的锁紧轴和球座之间滑动磨损后所呈现的结构形态和易磨损区域分布。结果表明:在一定范围内,随着圆弧面半径逐渐增大,体积磨损量呈现先减小后增加的趋势,最大滑移距离和最大穿透深度逐渐减小,最大变形量受圆弧面半径的影响较小,推荐最优半径为28~30 mm。仿真分析和现场试验结果表明,锁紧轴和球座侧滑会导致锁紧轴圆弧凸面沿圆周方向出现明显的磨损且边沿处出现“尖角”,球座圆弧凹面边沿厚度减小,形成环形凹槽且呈“卷曲变形”。该研究可以为十字万向轴的运动副的结构优化设计及耐磨性的提高提供参考。

万米深井SDCK1井超大尺寸井眼钻井技术

万米深井SDCK1井上部超大尺寸井眼段钻进过程中,面临着钻具安全风险高、井眼清洁效率低、井身质量控制难、PDC钻头磨损快、超大尺寸超重套管下入难等技术难点。为解决这些技术难点,开展了钻具安全保障技术、超大尺寸井眼井筒清洁工艺优化、耐大排量冲蚀测斜工具研制、“个性化PDC钻头+大扭矩中空螺杆”优选及超大尺寸超重套管下入技术措施优化等关键技术研究,形成了万米深井超大尺寸井眼安全高效钻井技术。SDCK1井ϕ812.8 mm和ϕ593.7 mm超大尺寸井眼钻进过程中应用了该技术,确保了钻具安全、井眼清洁和井身质量控制(井斜角不超过1°),同时提高了单只进尺和机械钻速,使超大尺寸超重套管顺利下至设计位置。SDCK1井超大尺寸井眼段的顺利完钻,为四川地区超大尺寸井眼段的安全高效钻进提供了技术借鉴。

随钻超声阵列测井仪激励电路设计

通过随钻超声阵列测井仪获得的井壁反射特性可实时跟踪井身剖面,获取裂缝地层信息。随钻超声阵列测井仪激励电路的稳定性直接决定声波数据的质量。采用双极性脉冲激励的方式设计了一种随钻超声阵列测井仪激励电路,介绍了该电路的软、硬件设计,并进行了电路性能测试和实际测井试验。试验结果表明,该电路激励能量强,波形调节灵活,能够有效压制后续拖尾信号;同时测井信号清晰稳定,能够有效反映地层性质,为随钻阵列超声测井提供了技术参考。