Improved rotary damping system for a drill string used for DTH and rotary drilling

Abstract

The present invention relates to an improved damping system for effective and safe use in a DTH and rotary drill. This system aims to alleviate the problems caused by heavy impacts and torsional forces that the drill machine and the drill string transmit to each other and withstand, mitigating them by incorporating nitrile seals, damped rigid metal plates between high-density polyurethane pieces, and other improvements. The system comprises: - a body of the damping system; - a protective casing, which has hatches for visually inspecting same; - an upper threaded conical portion for screwing onto a drill machine; - an upper portion bolted to the body by a series of upper fastening bolts; - an intermediate area comprising metal plates which are connected by polyurethane damping pieces interposed between them and which are arranged around the intermediate area of the body of the damping system; - an improved system for adjusting the lower damper; - a lower portion bolted to the body by lower securing bolts; and - a lower threaded case into which a drill string can be screwed. All of this is configured so that the improved damping system provides effective damping between the drill machine, the drill string and a tricone bit (not shown) of a rotary drill and a bit of a rotary-percussion drill.

Description

[0001] IMPROVED ROTARY DAMPING SYSTEM FOR DRILL STRING FOR DTH AND ROTARY DRILLING

[0002] Field of Invention

[0003] The present utility model relates to the field of systems and devices for conventional (rotary) drilling equipment and DTH (Down the Hole or bottom of the well) drilling.

[0004] Specifically with an improved rotary damping system for drill string for DTH and rotary drilling.

[0005] The operation of a damping system used in rotary and rotary-percussive drilling is described.

[0006] Background of the Utility Model

[0007] The following discussion of the prior art is intended to present the utility model in an appropriate technical context and allow its advantages to be properly appreciated. However, unless clearly stated otherwise, reference to any prior art in this description should not be construed as an express or implied admission that such art is widely known or forms part of common knowledge in the field of shock-damping systems to be positioned between the drilling machine, the drill pipe, and the drill bits.

[0008] DTH (Down the Hole) and rotary drilling rigs are highly efficient drilling equipment used in mining. Specialized operators depend on them for better and more efficient drilling and subsequent blasting to extract minerals from a deposit. Drilling rigs differ in their operation and are used in different types of drilling according to specific requirements.

[0009] For optimal drill operation, a damping system is used, threaded or spun directly onto the drive shaft of the rotary head. This damping system helps protect the rotary gearbox and mast components from torsional and axial vibrations / impacts under moderate and extreme drilling conditions. As a result, drill maintenance and downtime are reduced, performance is increased, and production costs are lowered.

[0010] Several aspects are relevant to achieving these objectives, such as the effectiveness of the damping system used, once these require replacement or repair, among others. The design for improvements to the damping system in this utility model can influence and improve some of the aspects previously identified in the field of systems for improving DTH (Down-the-Hole) and rotary drilling equipment and devices.

[0011] Good practices in drilling

[0012] Level the drill rig before starting each well

[0013] After each tool change or drill movement, check the column is “plumb” against the deck bushing before starting operation.

[0014] Store columns horizontally, with at least three support points, taking care to preserve threads.

[0015] Do not place washers or any foreign object in the joint of two tools

[0016] Discard top subsal end of shock absorber life

[0017] Discard sub-bits when the bar changes or rotates

[0018] Periodic lubrication of threads (column maintenance) Require certification of thread sizes from suppliers

[0019] Bar replacement and rotation based on wear (diameter measurement), not by time or length

[0020] Check threads and mirrors during rotations and changes

[0021] Respect bar change procedures: start slowly for correct coupling.

[0022] Damping systems for DTH drilling rigs are characterized by the reduction of shocks and vibrations for a smoother drilling operation and improved performance. Additionally, they extend the service life of the drill head, drill string components, and drill bits.

[0023] In the prior art, one should consult Canadian patent document No. CA3237684A1, which relates to a subassembly or damper, rock drilling equipment, and a method for absorbing vibrations in rotary and DTH drilling. The subassembly or damper is intended to transmit torque and axial forces between a rotary head and a drill bit. An axial floating arrangement provides limited relative axial movement between the subassembly's coupling elements. The arrangement comprises several axial drive pins for transmitting torque. The first ends of the drive pins are fixed, while the second ends are loosely mounted, allowing the drive pins to bend under torsional stress. Therefore, the drive pins act as torsional damping elements.

[0024] Also, see Chinese patent document No. TWI354055B, which relates to a device for reducing vibrations and impacts generated on the drill string, comprising: - a through-cylinder housing, in which - a first end and a second end are coupled together by means of a radial interlocking groove formed by the contact surfaces of the first and second ends; the shock absorption assembly is arranged in the outer housing of the through-hole. It is used to absorb and dissipate the impact.The reduction device is generated by a vibration and impact device on the drill string, in which the contact surfaces form at least a portion of an outer radial wall that surrounds and envelops the shock absorption assembly, further comprising: - a protruding portion, extending longitudinally at least a protruding portion of the ordinary cylindrical outer casing into at least a recessed portion of the second end of the passage, also comprising a piston between the two elastic discs, the piston including a radially extending flange positioned between the elastic discs, the flange being adapted to transmit the force to the elastic discs.Therefore, a system is needed to improve the problem caused by the large shocks and torsions received and endured between the rotary head and the drill string by resolving them through the incorporation of nitrile seals, rigid metal plates cushioned between high-density polyurethane pieces and other improvements, saving costs, reducing maintenance and downtime for lubrication.

[0025] Utility Model Summary

[0026] The utility model object is to provide an improved shock-absorbing system to be positioned between the drill string of a drilling machine and the ticonic bit, which solves the previously mentioned technical problems.

[0027] The utility model relates to the field of systems and devices for conventional (rotary) drilling equipment and DTH (down the hole or bottom of the well) drilling.

[0028] Specifically, an improved damping system for rotary and DTH drill strings is described. The operation of a damping system used in rotary and rotary-percussive drilling is also described.

[0029] The shock absorber absorbs the recoil energy of shock waves during drilling to reduce vibrations and increase the life of the drill string. It operates by absorbing and converting the recoil energy into heat through the controlled movement of a damping piston in response to the impact.

[0030] Floating type shock absorbers are used in both inclined and vertical drilling operations to reduce vibration and wear on drill string components and drilling equipment.

[0031] The floating-type damper allows a limited amount of axial displacement between the drill string and the rotary drive while assembling and disassembling the threaded connections, and also reduces shock and vibration induced by the rotary or hammer bit. Typically, the pin-up / box-down configuration machined into the top cover and piston is suitable for most drill rigs and drill string combinations without any modification to the drilling equipment.

[0032] The present utility model improves the performance of a damping system by means of an improved damping system comprising a series of high-strength steel segments, joined by means of flexible elements called monomer chain elastomers, made from a thermoset elastic polymer.

[0033] The shock waves and vibrational energies generated by the drill bit during rock drilling are absorbed through rigid segments connected by the aforementioned flexible elements. The remaining torsional, lateral, axial, and vibrational energies inherent in the rock drilling process are absorbed by the integrated assembly and immediately released into the atmosphere.

[0034] The modifications and improvements incorporated into the shock absorber system known in the art are as follows:

[0035] - Complete structural modification of the upper pin in the seal housing area.

[0036] - Implementation of flat backup seals

[0037] - Complete structural modification of the inner tube in the seal housing area.

[0038] - Complete structural modification of the upper end flange, considered for the installation of a protective sleeve.

[0039] - Implementation of the protective shirt, which has a hatch for inspection and evaluation of wear on the external parts.

[0040] - Complete modification of the shock absorber adjustment system (lower end).

[0041] Belleville System

[0042] Disc springs are used within the shock absorber assembly to allow a certain amount of axial movement between the drill string and the rotary head. These disc springs accommodate operating loads ranging from 8,000 to 120,000 lbs (3,628 kg to 54,431 kg), thus helping to maintain continuous contact between the ticone bit and the formation, in most cases reducing the possibility of fracturing or breaking the bit inserts. Urethane drive blocks located within the shock absorber assembly provide 100% transfer of torque and rotation from the drive spindle to the drill string, as well as absorbing torsional vibration transmitted by the bit.

[0043] Fixed piston (the most commonly used type of damping system today): The fixed piston damper is assembled with a central inner tube, the "fixed piston," which transmits axial loads to high-density polyurethane pads. This allows for complete absorption of axial movement between the drill string and the rotary unit. The polyurethane blocks (upper and lower pads) receive axial loads ranging from 54,431 kg to 90,719 kg (120,000 to 200,000 lbs, 534-890 kN). This system minimizes vibrations along the drill string, maintaining constant contact between the tricone bit and the rock. The seal system is made of nitrile, which tolerates temperatures from -40°C to 110°C, eliminating the need for lubrication of the moving damping parts.

[0044] Smooth Drive

[0045] A rubber compensator is a flexible connector made from natural or synthetic elastomers, fluoroplastics, and fabrics, and may include metal reinforcements if required. Compensators are used to absorb movement in a piping system while containing the pressure of the fluid or medium flowing through it.

[0046] This and other objectives, which will become evident below, are achieved by means of the improved damping system, as defined in claim 1.

[0047] A number of non-exhaustive embodiments, variants, or alternatives of the invention are defined by means of the dependent claims.

[0048] In one aspect, an improved damping system for a DTH drill string.

[0049] Effects of the Utility Model

[0050] The present utility model comprises a technological advantage over known damping systems in the art by improving the coupling parts, housing for the seals, implementation of backup seals, flat seals, and upper flange for installing a protective sleeve to monitor wear.

[0051] Brief Description of the Figures

[0052] To make the present utility model more easily understood, reference will now be made to the accompanying figures which illustrate a preferred embodiment:

[0053] Figure 1 shows a perspective view of the underside of the damping system, according to the utility model.

[0054] Figure 2 shows an elevation and cross-sectional view from the longitudinal axis towards the right side face, according to the utility model.

[0055] Figure 3 shows in detail one of the high-strength rigid metal segments, according to the utility model.

[0056] Figure 4 shows in detail a rigid metal segment of high resistance at the front and one at the back joined by means of a high-density polyurethane piece, according to the utility model.

[0057] Figure 5 shows an elevation view of the shock absorber system with an upper and lower protective housing, shown in a segmented line, according to the utility model.

[0058] Figure 6 shows an elevation view of the upper and lower protective housing, according to the utility model.

[0059] Figure 7 shows an elevation view of the upper portion of the seal housing area, according to the utility model.

[0060] Figure 8 shows an elevation view of the upper flange that allows for the installation of the protective housing, according to the utility model. Figure 9 shows an elevation view of the modified damper adjustment system, according to the utility model.

[0061] Figure 10 shows an elevation view of the modification of the inner tube specifically the seal housing area, an implementation of backup seals and implementation of flat seals, according to the utility model.

[0062] Utility Model Description

[0063] The present utility model will now be described with reference to the following modalities, which should be considered in all respects as illustrative and not restrictive. In the figures, the corresponding characteristics within the same modality or common to different modalities have been assigned the same reference numbers.

[0064] In Figure 1, a perspective view of the improved damping system (1) can be observed, which comprises a protective housing (2) around its periphery, which includes an inspection hatch (4) for checking and evaluating the wear of external parts (5), towards the free ends of each of the inspection hatches (4) there is an elongated perforation

[0065] (6) which houses inside a retaining bolt (not shown), so as to allow removal and repositioning of each of the inspection hatches (4) of the damping system (1), towards the rear face is located the lower portion

[0066] (7) joined by a series of lower fastening bolts (11) around its periphery, centered with respect to this lower piece is a lower box (9) inside which is located a large diameter spun portion (10), which allows a drill string (3) to be fixed.

[0067] In Figure 2, an elevation view can be observed from the longitudinal axis (12) towards the left face (Cl) and a sectional cut view from the longitudinal axis (12) towards the right face (CD). In the elevation view, the shock absorber system (1) can be observed without its protective casing (2) (see Figures 5 and 6). From the upper end (ES), in a downward direction, a spun upper conical portion (13) is located centered with respect to the axial axis (12). This portion connects to the rotation unit of the drilling equipment (14) (shown schematically). It rests on the upper portion (15) attached to the metal casing of the shock absorber body (1) by means of a series of upper fixing bolts (8) located around the upper periphery. Each of these bolts (8) coincides with its corresponding lower bolt pairs (11).Downward from these bolts (8) is located a flange (40) that allows fixing the protective housing (2), under the upper portion (15) is located a series of rigid, high-strength metal segments or plates (16) in the shape of a stylized wedge (see figures 3 and 4), which from their left face (Cl) gradually increase in thickness (17) until forming a wedge-shaped portion (18) on their right face (CD), from their upper end (ES) to their lower end (El) in the same way their thickness gradually increases until reaching their flat base (19), on their right side face there is a sign of perforations for the passage of air (20), each of these rigid metal plates (16) are arranged vertically around the periphery of the damping system (1) joined by means of a high-density polyurethane piece (21) with the same shape as each of the rigid metal plates (16), these polyurethane pieces (21),Located inside the damping system (1), they provide 100% transfer of torque and rotation from the drive shaft to the drill string (3). They also absorb torsional vibration transferred from the conical bit. At their left and right free ends, these high-density polyurethane pieces (21) have alternating semi-cylindrical cutouts (22) that allow air passage for ventilation. At the left side end, the semi-cylindrical cutout (22) is located on the back face (23), and at the right side end, the semi-cylindrical cutout (22) is located on the front face (24) of a polyurethane piece (21). These polyurethane pieces (21) have a continuous, greater thickness.It can be observed that the free end of each of the semi-cylindrical cutouts (22) fits snugly with a % cylinder zone (25) located at the thickest end (26) of each of the rigid metal plates (19), these perforations or semi-cylindrical cutouts (22) form an upper ventilation duct (27) and a lower ventilation duct (28). From the axial axis (12) towards the right face (CD) the damping system (1) is observed in sectional cut, from the upper end (ES) downwards an internal upper flange (29) in the form of a disc is located which facilitates the installation of the protective casing (2), continuing downwards an adjustment system (30) of a lower damper (31) is located, which consists of a peripheral support of round section (32) that prevents the lower damper (31) from becoming uncentered or coming out of its position and towards its support base (33) a flat peripheral support (34) is located,Inside the inner tube (TI), (see figure 10), towards the lower end is located a spun box (9) which allows connection to the drill string (3) (shown schematically) in the inner spun portion (10) of the spun box (9).

[0068] In figures 5 and 6, an elevation view of the shock absorber system (1) can be observed, on which in a segmented line (figure 5) and in a continuous line (figure 6), around its periphery, the protective casing (2) is located, which comprises towards its upper (ES) and lower (El) end a series of cylindrical perforations (35) for fixing to the surface of the shock absorber system (1), in a downward direction the connection of the drill string (3) is located schematically.

[0069] In Figure 7, an elevation view of the upper portion (15) housing area for seals made from nitrile can be observed, which allows to tolerate temperatures from -40°C to 110°C eliminating the need for co-lubrication of the moving parts of the damping system (1), where in the upper portion (15) it incorporates an intermediate nitrile backup seal (36), an upper flat nitrile seal (37), and a lower flat nitrile seal (38).

[0070] Figure 8 shows the modification of the base (39) of the upper portion (15) which allows the placement of a flange (40) (see figures 2 and 5) which facilitates the installation of the protective casing (2), to be bolted through the cylindrical perforations (35) to the body of the shock absorber system (1).

[0071] Figure 9 shows a detail of the lower shock absorber (31), formed by two flattened ellipse-shaped bodies (41) joined by a central metal piece (42), fixed and secured at both its upper end (ES) and lower end (El) by means of a sealing ring (AS) centered with respect to the axial axis (12).

[0072] Figure 10 shows a cross-sectional view of the inner tube (TI) at the upper end (ES) where a peripheral recess (43) is located towards the periphery, which allows a flat nitrile seal (44) to be housed inside. In a downward direction at this upper end (ES), a second recess (45) with a rectangular section is located around the outer periphery of the inner tube (TI). This recess (45) allows the installation of a higher flat nitrile seal (46), centered with respect to the axial axis (12). A top flat nitrile seal (47) is located centered in the perforation of the inner tube.

[0073] Industrial Application

[0074] The present utility model is related to an improved rotary damping system for drill string for DTH (down-the-hole) and rotary drilling, according to its application it finds use in industry and in particular in the mining industry, construction industry, engineering industry, metalworking industry, steel industry, toolmaking industry, pipemaking industry, electronic systems industry, CAD / CAM assisted design industry, special materials industry for making seals (from achloronitrol-butadiene rubber elastomer).

[0075] List of reference numbers

[0076] AS Lower shock absorber seal ring

[0077] C Body of shock absorber system

[0078] Left face

[0079] CD Right side

[0080] ES Upper extreme

[0081] The lower end

[0082] Intermediate Zone I

[0083] S Nitrile Seals

[0084] TI Inner Tube

[0085] 1. Shock-absorbing system. Protective housing.

[0086] Drill string

[0087] Inspection hatches

[0088] External parts

[0089] Elongated perforation hatches

[0090] Lower portion

[0091] Upper fastening bolts

[0092] spun box

[0093] Large inner diameter spun portion of lower spun box

[0094] Lower fastening bolts

[0095] Axial axis

[0096] Upper conical portion spun with large inner diameter

[0097] drilling rig

[0098] Upper portion

[0099] Rigid, damped metal plates

[0100] Increased plate thickness

[0101] Wedge-shaped portion

[0102] Flat base wedge-shaped portion

[0103] Perforations for air passage

[0104] High-density polyurethane piece

[0105] Semi-cylindrical cut

[0106] Back side

[0107] Front face

[0108] Cylinder % zone

[0109] Thickest end

[0110] Upper ventilation duct

[0111] Lower ventilation duct

[0112] inner upper flange

[0113] Lower shock absorber adjustment system

[0114] Lower shock absorber

[0115] Peripheral support, round section, lower shock absorber base

[0116] Flat peripheral support

[0117] Cylindrical perforations

[0118] Intermediate nitrile backup seal

[0119] Nitrile top flat seal

[0120] Nitrile bottom flat seal

[0121] Base upper portion

[0122] Flange upper portion

[0123] Bodies in the shape of a flattened ellipse, lower damper

[0124] Central metal piece lower shock absorber

[0125] Peripheral recess with rectangular section

[0126] Nitrile top flat seal inner tube

[0127] Second peripheral recess with rectangular section

[0128] Second recess nitrile flat seal

[0129] Top flat nitrile seal centered on inner tube bore

Claims

AMENDED CLAIMS received by the International Bureau on 17 July 2025 (17.07.2025) 1. A rotary damping system (1) incorporating inside nitrile seals (S), rigid damped metal plates (16) located radially between high-density polyurethane damping pieces (21), CHARACTERIZED in that it comprises: - a body (C) of cylindrical shape - a protective casing or sleeve (2), which surrounds the cylindrical body (C) comprising at least inspection hatches (4) - a tapered upper spun portion (13) for screwing on a drilling unit (14) - an intermediate zone (I) comprising a first elastic element (E1) formed by metal plates (16) - a lower damping system (31 ) in the form of a peripheral support of round section (32) - a lower portion (7) bolted to the body (C) by means of lower fastening bolts (11).

2. The damping system according to claim 1, CHARACTERIZED in that inside the upper portion (15), there is a housing area for nitrile seals parallel to the X-axis, an intermediate backup seal (36), an upper flat seal (37) and a lower flat seal (38), towards the lower end (El) of this upper portion (15) there is a flange (40), bolted through the cylindrical perforations (35) to the body of the damping system (1).

3. The damping system according to claim 2, CHARACTERIZED in that at the upper end (ES) it comprises an internal upper flange (29).

4. The damping system according to claim 3, CHARACTERIZED in that centered around the axial axis (12) is located the inner tube (TI) in whose upper end (ES) a peripheral rectangular recess (43) houses a flat nitrile seal (44), downwards from this upper end (ES) is located a second rectangular recess (45) parallel to the Y-axis, around the outer periphery of the inner tube (TI), recess (45) for a flat nitrile seal (46), centered with respect to the axial axis (12) is located at the upper vertex a backup nitrile seal (47).

5. The damping system according to claim 4, CHARACTERIZED in that the lower damper (31) comprises two flattened ellipse-shaped bodies (41), joined by an intermediate central metal piece (42), fixed and secured at both their upper end (ES) and lower end (El) by means of an upper and lower sealing ring (AS) centered with respect to the axial axis (12).

6. The damping system according to claim 5, CHARACTERIZED in that the inner tube (TI), specifically the seal housing area, is modified to accommodate backup seals (36) and flat nitrile seals (47).

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