高能射流式液动锤冲击系统理论研究及关键结构优化分析

发布时间：2018-07-29 18:23

【摘要】：干热岩资源作为一种新兴清洁能源,凭借其庞大的热储量、巨大的开采潜力以及战略价值受到全世界的广泛关注。由于干热岩地层埋藏深且地质条件复杂、岩层硬度高、可钻性差,现有钻进工艺存在钻进效率低、井下事故率高、钻井周期长成本高等突出难题。为此,本文提出干热岩快速钻井用高能射流式液动锤钻进技术,该技术在同种规格条件下具有冲击功大、碎岩效率高、成孔质量好、易损件少、使用寿命长等特点,尤其适用于强度高、硬度大、研磨性强、可钻性差的干热岩地层钻进,且不受井内围压条件限制,有望突破深井乃至超深井硬岩地层钻进难题。本文围绕高能液动锤输入端压力高、冲击功大等特点,对新型高能射流式液动锤的关键结构如射流元件、缓冲机构、缸体、冲锤等等展开深入研究。探讨高能液动锤在高压动载条件下的密封可靠性、大冲击功下的耐久性以及能量传递的合理性等等。本文的研究内容及主要结论如下:(1)新型全硬质合金射流元件解决了高速流体冲蚀问题,然而由于硬质合金元件脆性大、冲击下易断裂的特点,严重影响了高能液动锤的工作可靠性性。为此设计了碟簧缓冲、缓冲腔缓冲以及中接头碰撞缓冲三种回程缓冲机构,运用了Fluent与ANSYS/LSDYNA数值仿真分析手段对其缓冲效果进行评价,并对照试验进行了验证。结果表明:三种回程缓冲机构均能有效降低冲锤回程冲击功,保护硬质合金射流元件免受大能量冲击破坏;(2)针对高压高能冲击器特点分析现有密封结构存在的问题,并进一步提出合理密封结构。得出的结论如下:1)高压流体环境下碟簧对高能冲击器中密封圈工作状态具有重要影响,其变形后产生的间隙张开量是造成密封圈损坏的直接原因。随着碟簧数量增加,密封圈密封压力提高,当碟簧为五片叠合时,可满足现有高压高能冲击器的密封要求;2)缸体结构采用内通道一体式结构替代了原有的内外缸配合的结构方式,大幅减少了密封圈的使用,提高了高温高压环境下的密封可靠性;(3)对射流式冲击器冲锤结构参数与能量传递效率关系展开了深入研究,讨论等速度等质量条件下不同结构参数的冲锤与不同种类岩石撞击时,冲锤长度和直径对能量传递效率的影响,得到结论为:1)冲锤结构参数与碎岩效果的关系同所钻进的地层情况密切相关;2)冲锤长度并非越长越好而是存在最优值,当超过最优值岩石吸能值开下降,而岩石吸能值则随着冲锤直径的增加而增加;)冲锤结构对岩石吸能值的影响与冲锤冲击末速度有关,冲锤的冲击末速度越大,岩石吸能值越高,碎岩效果越好;4)冲锤与钻头相对面积大小决定了应力分布状态,应力集中往往出现在较小的撞击面边缘,而最大应力始终出现在钻头尾部,设计时应着重考虑钻头强度;5)对于高速冲击且用于硬岩钻进的高能射流式液动锤而言,冲锤结构对能量传递影响可忽略;(4)通过数值模拟仿真分析,建立冲锤摆动与液动锤冲击能量利用率的关系,得出:1)冲锤摆动会造成冲锤在运动过程中频繁与侧壁面摩擦碰撞,造成不必要的能量损失,降低钻进效率;2)凸起高度、凸起位置、活塞杆直径、活塞杆与缸体配合间隙均会影响能量传递;3)初始速度增加,冲锤速度损失加剧,而由不平整度引起的能量损耗比率却随之减少。表明高能液动锤相对于常规液动锤更具优势,对于长时间冲击碰撞造成的撞击面局部变形或破损以及配合间隙等引起的摆动并不十分敏感,对于加工精度要求相对较低,既保证了长期恶劣工况下工作的稳定性,又降低了加工成本;(5)探讨将双射流喷嘴、带过渡腔旋转射流喷嘴以及环喷型旋转射流喷嘴应用于潜孔锤钻头的可行性,并运用Fluent对带有三种喷嘴的钻头孔底流场分布进行研究,分析对岩屑运移、辅助孔底碎岩等方面的影响。结果表明低压小流量入口条件下双射流喷嘴和带过渡腔旋转射流喷嘴无论从岩屑运移还是辅助碎岩角度效果均不理想,而环喷型旋转喷嘴通过将旋转射流和环喷射流相结合,有效降低了喷嘴出口中心处地层压力,在井底形成高低压交替的应力场分布,降低孔底静液柱压持效应,同时增强孔底岩屑的悬浮和扰动,与常规斜喷嘴相配合可在高效清洁孔底的同时提高机械钻速。本论文的创新点主要有:(1)创新性提出三种缓冲机构设计,通过数值仿真技术与试验手段对缓冲机构设计的合理性进行验证;(2)首次针对高压流体环境下的冲击动载对冲击器内部密封影响进行了研究,分析了冲锤回程冲击对于液动锤上部各构件间密封特性的影响,建立了间隙分离量与密封圈工作稳定性关系,并提出了合理的碟簧布置方式;(3)采用ANSYS/LSDYNA数值模拟手段替代传统的解析法,对射流式冲击器冲锤结构与能量传递关系进行了研究,并分析了冲锤径向摆动对能量传递效率的影响;(4)论文首次提出将环喷型旋转射流喷嘴应用于高能射流式液动潜孔锤球齿钻头。
[Abstract]:Dry hot rock, as a new kind of clean energy, is widely concerned all over the world because of its huge thermal reserves, huge exploitation potential and strategic value. Because of deep buried and complicated geological conditions, the hardness of the rock layer is high and the drillability is poor. The drilling efficiency is low, the accident rate is high, and the drilling cycle is long. In this paper, the high energy jet hydraulic hammer drilling technology is put forward in this paper, which has the characteristics of high impact power, high crushing efficiency, good hole quality, few vulnerable parts and long service life under the same specification, especially for dry hot rock with high strength, high hardness, strong abrasiveness and poor drillability. It is hopeful to break through the difficult problems of hard rock formation in deep and ultra deep wells without confining pressure conditions in the well. In this paper, the key structures of the high energy hydraulic hammer are high pressure and great impact power, such as the key structure of the new high energy jet hydraulic hammer, such as the jet element, the buffer mechanism, the cylinder body and the punching hammer. The sealing reliability of the hydraulic hammer under high pressure dynamic load conditions, the durability of the high impact power and the rationality of the energy transfer, and so on. The contents and main conclusions of this paper are as follows: (1) the new all hard alloy jet elements have solved the problem of high speed fluid erosion, however, because of the large brittleness of the hard alloy components, the fracture is easily broken under the impact. The working reliability of high energy hydraulic hammer is seriously affected. Three kinds of return buffer mechanisms are designed, which are disc spring buffer, buffer cavity buffer and middle joint collision buffer. Fluent and ANSYS/LSDYNA numerical simulation analysis methods are used to evaluate the buffer effect and verify the results compared with the test results. The results show that three backstroke buffers are tested. The structure can effectively reduce the impact work of the hammer back, protect the hard alloy jet components from the large energy impact damage. (2) in view of the characteristics of high pressure and high energy impactor, the existing seal structure is analyzed, and the reasonable seal structure is further proposed. The conclusions are as follows: 1) the disc spring in high pressure fluid environment has the seal ring in the high energy shock device. The gap opening after the deformation is the direct cause of the seal ring damage. With the increase of the disc spring number, the sealing pressure of the sealing ring is increased. When the disc spring is five laminated, it can meet the sealing requirements of the existing high pressure high energy impactor; 2) the cylinder structure is replaced by the inner channel integral structure. The structure mode of internal and external cylinders greatly reduces the use of sealing rings and improves the reliability of sealing in high temperature and high pressure environment. (3) the relationship between the structural parameters of the impingement hammer and the energy transfer efficiency is deeply studied, and the impact of the impingement hammer with different types of rock under the same velocity and other quality conditions is discussed. The effect of hammer length and diameter on energy transfer efficiency is concluded as follows: 1) the relationship between the structural parameters of the hammer and the effect of rock breaking is closely related to the formation of the drilling strata; 2) the length of the hammer is not the longer the better, but the best value, and the rock energy absorption value increases with the increase of the diameter of the hammer when the maximum value exceeds the optimum value. The impact of the impact hammer structure on the rock energy absorption value is related to the impact end velocity of the hammer, the greater the end velocity of the impact hammer, the higher the rock energy absorption value, the better the rock crushing effect; 4) the relative area between the hammer and the bit determines the stress distribution state, and the stress concentration often appears on the smaller impact surface edge, and the maximum stress always appears in the drill. Head and tail, the design should focus on the strength of the bit; 5) for high velocity impact and high energy jet hydraulic hammer for hard rock drilling, the impact of the impact hammer structure on energy transfer can be ignored. (4) through numerical simulation analysis, the relationship between the impact energy utilization ratio of the hammer swing and the hydraulic hammer is established, and 1) the flushing hammer will cause the punching hammer to be caused by the hammer. The friction collide frequently with the side wall during the movement, causing unnecessary energy loss and reducing drilling efficiency; 2) the height of the bulge, the position of the protruding, the diameter of the piston rod, the gap between the piston rod and the cylinder body will affect the energy transfer; 3) the initial velocity increases, the speed loss of the punching hammer is aggravated, and the loss ratio caused by the unevenness is reduced. The results show that the high energy hydraulic hammer is more advantageous than the conventional hydraulic hammer. It is not very sensitive to the local deformation or breakage of the impact surface caused by the long impact impact and the swing with the gap and so on. The requirement for machining precision is relatively low, which not only ensures the stability of the working conditions under the bad conditions for a long time, but also reduces the processing cost; (5 The feasibility of applying the double jet nozzle, the swirling jet nozzle with the transition cavity and the annular jet nozzle to the DTH hammer bit is discussed, and the distribution of the flow field at the bottom of the drill hole with three kinds of nozzles is studied by Fluent, and the influence on the movement of the cuttings and the auxiliary rock bottom rock is analyzed. The results show that the low pressure and small flow entry bar is shown. Both the two jet nozzles and the rotating jet nozzles with the transition cavity are not ideal for both the movement of the cuttings and the auxiliary rock. By combining the rotating jet and the annular jet flow, the annular jet nozzle effectively reduces the formation pressure at the outlet center of the nozzle, and reduces the bottom of the hole at the bottom of the well and reduces the bottom of the hole. The static liquid column compression effect, at the same time enhances the suspension and disturbance of the hole bottom rock, and can improve the mechanical drilling speed at the same time with the conventional inclined nozzles at the same time. The innovation points of this paper are as follows: (1) innovatively put forward three kinds of buffer mechanism design, through numerical simulation technology and test means to test the rationality of the design of the buffer mechanism. (2) (2) the impact of impact dynamic load on the internal seal of the impactor was studied for the first time. The influence of the impact of the hammer back to the seal characteristics between the components of the upper part of the hydraulic hammer was analyzed. The relationship between the clearance separation and the stability of the seal ring was established, and a reasonable arrangement of the disc spring was put forward. (3) the use of ANSYS/LSD YNA numerical simulation method is used to replace the traditional analytic method. The relationship between the impact hammer structure and energy transfer is studied, and the influence of the radial wobble on the energy transfer efficiency is analyzed. (4) the circular jet nozzle is applied to the high energy jet hydraulic DTH ball bit for the first time.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：P634.5

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