Shock absorber for drilling operation

Abstract

The utility model discloses a shock absorber for drilling operation, which comprises an upper joint, a balance cavity, a disc spring cavity, a driving cavity and a sealing cavity which are sequentially connected, a balance core shaft is arranged in the upper joint and the balance cavity, and a balance piston is sleeved on the balance core shaft; a pressing cap is arranged at the upper end of the balance mandrel, and the lower end of the balance mandrel abuts against the top end of the spline mandrel and is located on the outer side of the sealing cavity. The shock absorber for the drilling operation is convenient to install and maintain, high in overall strength, good in abrasion resistance and long in service life. According to the high-strength integral spline core shaft structure, the spline core shaft serves as a main stress part, the integral spline core shaft completely avoids the tripping risk in design, the integral strength of a tool is enhanced, and the use safety during operation of a shock absorber is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of downhole operation, especially relates to a shock absorber for drilling operation. BACKGROUND

[0002] In drilling operation, the impact load and the vibration load of the drill string are easily caused by the geological structure, the bit structure and the drilling pressure, and the shock absorber can effectively reduce the influence of the longitudinal vibration, the torsional vibration and the lateral vibration in the drilling operation, thereby avoiding the fatigue damage of the drilling tool or the fracture of the drill string. The shock absorber bears the function of absorbing the impact and reducing the load of the drill string in the drilling operation, and the higher strength and better wear resistance are the necessary characteristics to meet the operation requirements. However, in the existing tool design, the tool structure is complex, the split type mandrel affects the overall strength of the tool, the sealing surface area of the tool driving cavity is prone to eccentric wear during operation, which leads to hydraulic oil leakage and even cavity scrap, and meanwhile, the internal coating of the cavity is prone to falling off due to the influence of mud erosion, which affects the shock absorption effect and the service life of the shock absorber. SUMMARY

[0003] The utility model provides a shock absorber for drilling operation, aims at solving the above -mentioned problem.

[0004] The utility model discloses a shock absorber for drilling operation, including the upper joint, the balance cavity, the disc spring cavity, the driving cavity and the sealing cavity that connect gradually, the upper joint and the balance cavity install the balance mandrel in, the balance mandrel is equipped with the balance piston on, the balance mandrel upper end is provided with the pressure cap, and the balance mandrel lower end abuts the spline mandrel top, the spline mandrel lower end is located the sealing cavity outside, the spline mandrel upper end is equipped with the disc spring, be provided with the adjusting inner cover and the adjusting outer cover between the disc spring and the balance mandrel, the adjusting inner cover and the adjusting outer cover are equipped with respectively in the spline mandrel, the spline mandrel still is installed with the stop sleeve, and the stop sleeve sets up in the disc spring downside.

[0005] Further, 2 sets of sealing assemblies are arranged between the balance mandrel and the balance piston, and 2 sets of sealing assemblies are arranged between the balance cavity and the balance piston.

[0006] Further, the balance cavity is filled with silicon oil.

[0007] Further, the upper end of the driving cavity is connected with the male buckle of the disc spring cavity, and the lower end of the driving cavity is connected with the female buckle of the sealing cavity.

[0008] Further, the inner wall of the balance cavity is embedded with an alloy liner through a hot mounting process.

[0009] Further, a sealing assembly is arranged between the spline mandrel and the sealing cavity.

[0010] Further, the sealing assembly one, the sealing assembly two and the sealing assembly three are combined by the elastomer, the check ring and the wear-resistant band, and the wear-resistant band forms a "V-shaped" oil storage area with the external matching surface.

[0011] Compared with the prior art, the utility model has the advantages that:

[0012] The utility model provides a shock absorber for well drilling operation, convenient installation and maintenance, high overall strength, good wear resistance, long service life, high-strength integral spline shaft structure, spline shaft as main stressed member, integral spline shaft avoids tripping risk completely from design, enhances tool overall strength, guarantees the use safety of shock absorber operation, split type drive cavity structure, separately sets up sealed cavity structure, drive part and sealing part can be maintained and replaced independently, reduces the influence of single component damage on tool whole, improves tool maintenance efficiency, reduces tool use cost, high wear resistance hot loading inner inlay alloy bush structure, alloy bush higher hardness, better wear resistance, longer overall service life, improves tool use reliability, shortens tool maintenance period, can directly replace after bush wear, guarantees tool body integrity, self-lubricating combined sealing ring, sealing ring has oil storage area, can reduce the wear of spline shaft and sealing ring matching surface, lower maintenance and replacement frequency, higher overall service life of drilling tool. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is the structure schematic diagram of the utility model;

[0014] Figure 2 It is the spline shaft structure schematic diagram of the utility model;

[0015] Figure 3 It is the drive cavity and sealed cavity structure schematic diagram of the utility model;

[0016] Figure 4 It is the balance cavity structure schematic diagram of the utility model;

[0017] Figure 5 It is the balance piston structure schematic diagram of the utility model. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantage of the utility model more clearly, the following is in combination with the drawings and example, and the utility model is further detailedly explained.It should be understood that the specific example described here is only used to explain the utility model, and is not used to limit the utility model.

[0019] In the description of the utility model, it is understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model. In addition, in the description of the utility model, "a plurality of" means two or more, unless otherwise specifically limited.

[0020] Please refer to Figure 1 The utility model provides a technical scheme: a shock absorber for drilling operation, it includes: upper joint 1, pressure cap 2, balance cavity 3, balance mandrel 4, sealing assembly one 5, balance piston 6, alloy bushing 7, sealing assembly two 8, adjusting inner cover 9, adjusting outer cover 10, disc spring 11, disc spring cavity 12, stop sleeve 13, spline mandrel 14, drive cavity 15, sealing assembly three 16 and sealing cavity 17.

[0021] The utility model discloses a shock absorber is the design of up and down movement, upper joint 1 lower end connects the male buckle of balance cavity 3, the male buckle of balance cavity 3 lower end connects disc spring cavity 12, the male buckle of drive cavity 15 upper end connects disc spring cavity 12, drive cavity 15 lower end connects the female buckle of sealing cavity 17.

[0022] Balance cavity 3 and balance mandrel 4 form the hydraulic chamber, wherein balance piston 6 is arranged and filled with silicone oil, balance mandrel 4 and balance piston 6 are provided with two sets of sealing assembly one 5, and balance cavity 3 and balance piston 6 are provided with two sets of sealing assembly two 8.

[0023] When the drill bit encounters hard formation in drilling operation, the drill string is vibrated and the torque is generated, at the same time, the drill string exerts downward force on the shock absorber, the upper joint 1 of the shock absorber is connected with the balance cavity 3, the disc spring cavity 12, the drive cavity 15 and the sealing cavity 17 to move downward, and drives the adjusting inner cover 9 and the adjusting outer cover 10 to move downward, so that the force is transmitted to the disc spring 11;

[0024] The disc spring 11 is compressed and elastically deformed under the force, so that the disc spring 11 plays a buffering and damping role, at the same time, the hydraulic chamber formed by the balance cavity 3, the balance mandrel 4 and the balance piston 6 is acted on by the downward force, the space of the hydraulic chamber is reduced, the silicone oil is elastically deformed under the volume compression, so that the drill string load is absorbed or reduced, and the upward force is generated to push the balance piston 6 upward to balance the internal pressure of the tool;

[0025] As Figure 2As shown, during the shock absorber action, the load from the drill bit and the drill string exists longitudinal vibration, torsional vibration and lateral vibration. Affected by the torsional vibration, the whole tool string rotates, the spline spindle 14 directly connected on the tool string also rotates, the integral structure eliminates the failure caused by stress concentration at the traditional threaded connection, improves the torsional strength, improves the axial bearing capacity, effectively reduces the internal fatigue influence of the shock absorber, and ensures the dynamic stability of the whole tool string.

[0026] As shown, the split structure design of the driving cavity 15 and the sealing cavity 17 shortens the replacement time of the sealing element, and the maintenance cost is reduced; the reverse buckle design is adopted, so that the split design is firm like the integral type; and the split structure allows the sealing structure to be upgraded separately without replacing the whole driving module, and the adaptability of the tool is improved. Figure 3

[0027] As shown, the alloy bushing 7 is embedded in the balance cavity 3 through a hot mounting process, and the high-temperature process is matched with liquid nitrogen cold shrink assembly, so that the friction coefficient is greatly reduced, the stress distribution is uniform, local peeling is avoided, relative rotation does not occur under extreme working conditions, and the wear resistance life is significantly improved. Figure 4

[0028] As shown, the sealing assembly one disclosed by the utility model is combined by an elastic body, a check ring and a wear-resistant band, the elastic body adopts fluorine rubber which has strong stability and excellent mechanical properties, the check ring and the wear-resistant band adopt polytetrafluoroethylene which has good wear resistance, the good sealing property and wear resistance of the two materials greatly increase the life of the sealing ring combination as a whole. In addition, the customized wear-resistant band and the matching surface form a "V-shaped" oil storage area, when the shock absorber operates, the lubricating oil in the oil storage area forms a lubricating oil film on the surface of the part, not only reduces the friction coefficient, but also protects the matching surface to reduce wear. Figure 5

[0029] The above is only a preferred embodiment of the utility model, and is not used to limit the utility model, and any modification, equivalent replacement and improvement within the spirit and principles of the utility model should be included in the protection scope of the utility model.​​​

Claims

1. A shock absorber for use in well drilling operations, characterized by: It comprises upper joint, balance cavity, disc spring cavity, driving cavity and sealing cavity connected in sequence, the upper joint and balance cavity are provided with balance mandrel, the balance mandrel is provided with balance piston, the upper end of the balance mandrel is provided with pressure cap, the lower end of the balance mandrel abuts against the top end of the spline mandrel, the lower end of the spline mandrel is located outside the sealing cavity, the spline mandrel is provided with disc spring, the disc spring and the balance mandrel are provided with adjusting inner sleeve and adjusting outer sleeve, the adjusting inner sleeve and the adjusting outer sleeve are sleeved on the spline mandrel, the spline mandrel is further provided with stop sleeve, and the stop sleeve is located below the disc spring.

2. A shock absorber for use in drilling operations according to claim 1, characterized in that: Two sets of sealing assemblies one are arranged between the balance mandrel and the balance piston, and two sets of sealing assemblies two are arranged between the balance cavity and the balance piston.

3. A shock absorber for use in drilling operations according to claim 1, characterized in that: The balance cavity is filled with silicon oil.

4. A shock absorber for use in drilling operations according to claim 1, characterized in that: The lower end of the upper joint is connected with the male buckle of the balance cavity, the lower end of the balance cavity is connected with the male buckle of the disc spring cavity, the upper end of the driving cavity is connected with the male buckle of the disc spring cavity, and the lower end of the driving cavity is connected with the female buckle of the sealing cavity.

5. A shock absorber for use in drilling operations according to claim 1, characterized in that: The inner wall of the balance cavity is inlaid with alloy bushing through hot mounting process.

6. A shock absorber for use in drilling operations according to claim 1, characterized in that: The spline mandrel and the sealing cavity are provided with sealing assembly three.

7. A shock absorber for use in drilling operations according to claim 2, characterized in that: The sealing assembly one is combined by elastic body, check ring and wear-resistant band, and the wear-resistant band and the external matching surface form V-shaped oil storage area.

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