新型射流提高机械钻速机理及研究进展

在油气井钻井中，喷射钻井技术能够较大幅度地提高钻井速度，其实质是喷嘴射流辅助钻井破岩，提高了井底破岩效率。为此，文章在如何向井底输送能量和充分利用井下水力能量研究的基础上，进行了多种新型射流的研究与应用。文章对断续射流、自激振荡脉冲射流、自振空化射流和它激振荡脉冲射流4种形成新型射流的理论和方法，提高机械钻速机理进行了分析。现场应用结果表明，新型射流能够较大幅度地提高机械钻速，具有广泛的研究和开发应用前景。     

超高压射流辅助钻井技术研究进展

超高压射流辅助机械破岩钻井是提高深井钻井速度的一项前沿技术，关键技术包括井下增压器、超高压射流辅助破岩机理和钻头、超高压射流钻井参数和工艺等。主要介绍了超高压射流破岩机理、井底流场和辅助破岩钻头研究进展，在此基础上提出了超高压水射流辅助钻井技术的研究方向。     

利用井底超高压射流提高钻速研究

近10年以来,机械辅助高压射流破岩技术再次获得钻井界高度重视,被认为是提高硬地层、深井机械钻速的根本途径之一。利用井底超高压射流钻井技术是指基于水力与机械联合破岩方法和水力增压原理,开发一套具有射流式井底增压装置(DPS-1)和新型双流道高效破岩钻头(DCB-1)。创新点包括:开创了超高压水力与PDC机械联合高效破岩理论;研究开发了一套具有射流式井底增压装置;研究开发了一种新型双流道高效破岩PDC钻头。在温5-212井进行了现场试验,井段465.56~814.49m,进尺348.93m,纯钻11.33h,机械钻速30.79m/h,与同区块同井段牙轮钻头同比,机械钻速提高72.11%,钻头出口压力为70MPa。所以该技术是一个极富挑战性和可以充分发挥创造性的研究领域,这种技术潜在的经济效益是巨大的,也是目前可能有较大突破的一种联合破岩方法。     

���������꾮��Ч���һ����о�

现代旋转钻井破碎岩石是以机械破岩为主导方式，射流辅助机械破岩的目的是提高机械钻速。文章论述了牙轮钻头与岩石相互作用过程及岩石剪切破坏的内在规律；重点研究了射流的水楔作用对岩石裂纹产生、扩展、贯通及破坏的机理。实验结果表明，射流辅助钻井的门限压力是岩石抗拉强度的4.1倍，是抗压强度的26%；还与井底压差及其它岩石物理力学性质有关。同时指出，超高压射流的研究与应用是辅助钻井高效破岩的重要发展趋势。     

超高压射流辅助钻井技术研究进展

近年来,中国石油大学(北京)针对射流式井下增压器和超高压双流道PDC钻头先后开展了相关理论研究,并取得了突破性进展.综述了截止目前研究中重要的研究成果,包括射流式井下增压器增压原理和公式、射流换向元件水力结构特性(附壁特性和切换特性)、超高压双流道PDC超高压喷嘴结构设计、超高压射流辅助机械齿联合破岩机理,上述四项研究成果丰富和发展了超高压射流理论和PDC钻头超高压射流破岩机理理论,为射流式井下增压器今后的研究和优化奠定了重要的理论基础.     

水力喷射径向水平井钻井关键技术研究

水力喷射径向水平井技术可在垂直井眼内沿径向钻出呈辐射状分布的一口或多口水平井眼,从而增大与储层的接触面积,建立高导流通道,是一种经济高效的油田挖潜和增产增注技术,其关键技术包括射流破岩钻孔能力、水力参数计算、射流钻头自进与井眼延伸能力、井眼轨迹测量与控制等。针对上述关键技术开展了深入系统的研究:分析了目前应用于径向水平井钻井的各类型射流钻头的基本原理,建立了射流破岩比能模型,通过对比分析认为旋转多孔射流钻头综合破岩效果最佳;建立了径向水平井喷射钻进系统压耗计算模型,对比分析了不同直径连续油管的循环压耗,分析了相关参数对系统压耗的影响规律,为水力参数设计提供了依据;建立了旋转多孔射流钻头自进力计算模型与径向水平井延伸极限计算模型,对比了不同作业条件下径向水平井的延伸极限,为装备优选和径向井眼设计提供了依据;探讨了微机电惯性元件测量径向井眼轨迹的方法原理,为径向井眼轨迹测量提供了一种可行的方法。该研究成果可为形成水力喷射径向水平井技术体系与推广应用奠定基础。      

自激振荡式旋转冲击钻井工具在胜利油田的应用

摘要 :自激振荡式旋转冲击钻井工具安装于钻头上部 , 钻井液高速流经自激振荡器,形成水力脉冲作用于冲击传递杆,产生低幅高频机械冲击力传递至钻头,提高钻头破岩效果;所产生的水力脉冲再向下传递,经钻头水眼喷出形成脉冲射流,改善井底流场,提高井底净化和清岩效率,同时井底瞬时负压脉冲产生局部瞬时欠平衡,改变井底岩面破岩应力状态,可明显提高机械钻速。在胜利油田沙三和沙四段地层进行了钻井试验,无论是牙轮钻头还是 PDC钻头都有明显的提速效果,试验井段的机械钻速都提高了 30%以上,可成为钻井提速的新途径。     

利用定向自激振动射流提高机械钻速

在三牙轮钻头上,依据自振射流原理、水力辅助破岩原理和井底漫流场理论设计的一种新型的定向式风琴管自激振动射流喷嘴,提高了射流辅助破岩的能力,改善了井底漫流场,使清岩和破岩效率大幅度提高。8只钻头在河南双河油田和下二门油田的现场应用(相同的地层、相同的钻井机泵设备和相同的钻井施工水平)中,与其它类型钻头相比,单只钻头提高进尺20%以上、机械钻速15%以上,取得直接经济效益1.1万元,具有良好的应用前景。     

超高压射流辅助钻井钻头设计

水射流作为一种新型切割工具运用于石油钻井中,与机械联合破岩可提高破岩效率.根据破岩机理、井队设备与地面条件,不改变原来三牙轮钻头的结构,设计了超高压射流辅助钻井钻头.钻头的设计主要包括高压合金管的设计、定心夹具的设计、喷嘴的设计以及超高压连接体的设计.     

�꾮��Ч�����½�չ

钻井工程作业要破碎厚达数千米厚的岩石，其破岩效率的主要影响因素是井下地层岩石性质、破岩工具和方法。文章对岩石性质进行了基本分析，进行了喷嘴射流水力冲蚀辅助破岩门限压力的实验研究。提出了在现有旋转钻井方式下，钻头的机械破岩、喷嘴射流的水力辅助破岩和降低井底压差是提高钻井破岩效率的三个重要途径。分别阐述了它们能够提高钻井速度的机理、方法、关键技术和研究方向。同时介绍了激光钻井和电热能钻井新方法的研究与发展趋势。     

Investigation and Application of Self-Resonating Cavitating Water Jet in Petroleum Engineering

The paper presents the investigations of a unique jet as self-resonating water jet including the modulating principles, characteristics of impact pressure and rock erosion, and field applications in petroleum engineering in China. The research showed that jet nozzles designed with organ pipe structure could generate significant self-resonating cavitating water jets. As compared with conventional cone-shaped nozzle with 120° taper angle, the amplitudes of pressure fluctuation and maximum impact pressure of self-resonating cavitating water jets increase by 24 and 37%, respectively, and rock erosion efficiency increases by 1 to 2 times. Self-resonating water jets have been successfully applied in petroleum drilling engineering, with enhanced average rates of penetration of tricone bits by 31.2% and improved bit footages by 29.1%. Treatment of near wellbore formation and self-excited oscillating water injection with self-resonating water jets have resulted in economic efficiency.     

自振空化射流提高钻井速度的实验研究

空化射流用于提高钻井速度的可行性研究结果表明，在钻进作业中，利用空泡破裂产生强大破坏作用来提高钻探的效率，其效果显著，可行性高。室内实验表明，自振空化射流在比普通喷嘴射流更深的井底或更高的围压条件下，有更大的起始空化数和更强的空化能力。自振空化喷嘴起始空化数大都在1.0以上，最高达到1.67，而锥形喷嘴最高仅为0.43，围压下其冲蚀效率是锥形喷嘴的1~2倍。现场试验同样证实设计的自振空化射流喷嘴在保护钻头、减少钻头磨损及增加进尺、提高机械钻速方面有显著作用。     

CURRENT STATUS AND FUTURE PROSPECTS OF WATER JET TECHNOLOGY IN PETROLEUM ENGINEERING IN CHINA

ABSTRACT

This paper reviews the developments of investigation and application of high pressure water jet technology in both deep drilling and oil production including jet-bit drilling, extended nozzles and their combination to enhance hydraulic effectiveness at bottomhole, combined jet and mechanical drilling, new efficient jets (self-resonating cavitating jet, self-excited oscillation jet, swirling jet) used in drilling, horizontal well drilling by water jet, near wellbore plug removal with water jet, and high pressure water jet penetrating. Laboratory investigation and field application have coherently shown that high pressure jet drilling can increase the penetration rate. The hydraulic power of rock bit with extended nozzles and with crossflow hydraulics can increase by 30～40 percent, the bit footage by 40 to 50 percent and dynamic pressure by 90 to 110 percent compared with conventional bit. Combined jet and mechanical drilling can increase drilling rate by a factor of 3 in deep wells than conventional drilling method. New efficient jets can improve the penetration rate of bit with 20 to 60 percent higher, owing to the enhanced cutting and cleaning action. High pressure water jet drilling system can be used to drill multiple ultra-short-radius (0.3 m) radial horizontal wells at the same level without tripping the whipstock. Near wellbore plug removal with hydraulically rotating and pulsating water jet can increase oil production by 20 to 50 percent and increase water injection by 30 to 90 percent. New penetrating system by using high pressure water jet cutting can produce unobstructed radial tunnels with 3 meters in length and 14-25 mm in diameter information rocks and can be used in new well completions, recompilations, and workovers of older wells to enhance the production and injection efficiency. The paper shows the brilliant prospects of development and application of water jet technology.     

CURRENT STATUS AND FUTURE PROSPECTS OF WATER JET TECHNOLOGY IN PETROLEUM ENGINEERING IN CHINA

This paper reviews the developments of investigation and application of high pressure water jet technology in both deep drilling and oil production including jet-bit drilling, extended nozzles and their combination to enhance hydraulic effectiveness at bottomhole, combined jet and mechanical drilling, new efficient jets (self-resonating cavitating jet, self-excited oscillation jet, swirling jet) used in drilling, horizontal well drilling by water jet, near wellbore plug removal with water jet, and high pressure water jet penetrating. Laboratory investigation and field application have coherently shown that high pressure jet drilling can increase the penetration rate. The hydraulic power of rock bit with extended nozzles and with crossflow hydraulics can increase by 30∼40 percent, the bit footage by 40 to 50 percent and dynamic pressure by 90 to 110 percent compared with conventional bit. Combined jet and mechanical drilling can increase drilling rate by a factor of 3 in deep wells than conventional drilling method. New efficient jets can improve the penetration rate of bit with 20 to 60 percent higher, owing to the enhanced cutting and cleaning action. High pressure water jet drilling system can be used to drill multiple ultra-short-radius (0.3 m) radial horizontal wells at the same level without tripping the whipstock. Near wellbore plug removal with hydraulically rotating and pulsating water jet can increase oil production by 20 to 50 percent and increase water injection by 30 to 90 percent. New penetrating system by using high pressure water jet cutting can produce unobstructed radial tunnels with 3 meters in length and 14-25 mm in diameter information rocks and can be used in new well completions, recompilations, and workovers of older wells to enhance the production and injection efficiency. The paper shows the brilliant prospects of development and application of water jet technology.     

塔河油田深井脉冲空化射流钻井试验研究

塔河油田深井钻井水力能量利用效率低、机械钻速低、钻井成本高,严重制约了勘探开发速度。针对该油田钻井实际情况,结合二开φ241.3 mm井眼地层、钻具组合和水力参数,利用水力脉冲空化射流钻井技术提高机械钻速。该技术配合常规钻具和复合钻井钻具组合使用,脉冲空化射流发生器耦合脉冲射流和自振空化射流,改善井底流场及岩面应力状态,提高钻速。该技术在塔河油田进行了4口井5井次的现场试验,在常规泵压、排量、钻井液密度等参数条件下试验井深达6 162 m,试验井段与邻井相近井段在相近工况下机械钻速平均提高33.3%~74.3%,单套钻具纯钻时间超过260.0 h。试验结果表明,塔河油田二开井段砂岩、泥岩等地层配合PDC钻头应用水力脉冲空化射流钻井技术,能够很好地提高机械钻速。      

自振空化射流钻头喷嘴研制及现场试验

在风琴管谐振腔模型的基础上，给出了自振空化喷嘴的设计模式。用硬质合金为主要材料研制出了石油钻井用自振空化射流喷嘴。现场试验表明。自振空化喷嘴钻头与普通中长喷嘴钻头相比，钻井速度提高10．5%～49．3%，平均机械钻速提高31．2％．钻头进尺也相应增加29．1％。自振空化射流喷嘴具有广泛的应用前景。     

水力脉冲空化射流钻井机理与试验

在分析水力脉冲与空化射流调制机理的基础上,设计出一种新型水力脉冲与空化射流耦合的水力脉冲空化射流发生器,通过流体脉冲扰动和自振空化效应耦合,使进入钻头的常规连续流动调制成振动脉冲流动.钻头喷嘴出口形成脉冲空化射流,产生水力脉冲、空化冲蚀和局部负压效应,从而提高井底净化和辅助破岩效果.塔里木盆地6口井的现场试验结果表明,水力脉冲空化射流钻具对钻头类型、地层特性、钻井液密度、排量、动力钻具等具有良好的适用性,机械钻速提高10.1%～53.4%.水力脉冲空化射流发生器具有性能稳定、效果好、使用寿命长等特点,完全可以满足现场的需要.水力脉冲空化射流技术将为提高深井钻速提供一种切实有效的途径,具有较好的推广应用价值.图4表4参12     

Hydraulic Pulsed Cavitating Jet-Assisted Drilling

Abstract

How to improve drilling rate in deep wells has been a hot subject. Based on modulating pulse jet and cavitating jet, a new drilling tool is designed which couples advantages of both pulse jet and cavitating jet. When drilling fluid flows through the tool during the drilling process, fluid is modulated to pulse and cavitate. Thus, pulse cavitating jet is formed at the outlet of the bit nozzle. Because of jet pulsation, cavitating erosion and local negative pressure affect bottomhole rock. Cleaning and breaking is enhanced and penetration speed is improved. Oil field tests in five wells show good applicability of the tool to bit types, formation, drilling densities, flow rates, and dynamic hydraulic drilling motors, etc. As a result, penetration rates are improved ranging from 10.1 to 31.5%; the maximum working time is about 235.5 hr in downhole. Pulse and cavitating jet coupling will afford an effective means to improve drilling rate for deep wells.     

自进式旋转射流钻头破岩效果

利用有限的排量实现高效的破岩效率并尽可能增大径向水平井眼的延伸能力是实施新型径向水平井技术的关键,射流钻头的性能是该关键技术要解决的首要问题。在多孔射流钻头的基础上,设计研制了自进式旋转射流钻头,分析了其工作原理,并通过试验对自进式单孔旋转射流钻头、自进式单孔直旋混合射流钻头、自进式多孔旋转射流钻头以及自进式多孔直旋混合射流钻头随时间、射流压力和喷距的破岩钻孔规律进行了研究。研究结果表明:当喷距范围为9~12 mm、射流压力为20~35 MPa时,在相同的射流压力和喷距条件下,自进式多孔直旋混合射流钻头的破岩效果优于自进式多孔旋转射流钻头,其中1+4孔的多孔直旋混合射流钻头的破岩效果最好。设计得到的新型射流钻头可以提高径向水平井的钻进速度。     

水力脉冲空化射流欠平衡钻井提高钻速技术

研究了水力脉冲空化射流欠平衡钻井破岩、清岩、提高机械钻速机理,并在准噶尔盆地金龙3井进行了水力脉冲空化射流欠平衡钻井现场试验。研究结果表明,井底欠平衡状态下产生水力脉冲、空化冲蚀和局部负压效应,可改善井底流场,降低岩石的破碎强度,促进井底已破碎岩石及时脱离井底,减少反复切削及压持效应,从而达到提高机械钻速的目的。金龙3井相邻井段机械钻速对比表明,在钻井参数基本不变的情况下,采用牙轮钻头+水力脉冲空化射流发生器欠平衡钻井方式钻2 590~2 655 m井段和采用牙轮钻头+水力脉冲空化射流发生器+螺杆钻具欠平衡钻井方式钻2 655~2 759 m井段的机械钻速分别比采用欠平衡钻井方式钻2 485~2 590 m井段的平均机械钻速提高19.8%和87.1%。图5表2参14