A nozzle, forward nozzle, rearward nozzle and related applications

Abstract

The application discloses a nozzle, a forward nozzle, a backward nozzle and related applications. The nozzle comprises a forward nozzle and a backward nozzle. The first end of the forward nozzle is provided with a first spherical surface, and the second end is a circular arc cone body. The forward nozzle further comprises a first nozzle hole which is composed of a first flow guide cone hole, a first straight-through hole, a second flow guide cone hole and a second straight-through hole which are sequentially connected. The front end of the backward nozzle is provided with a second spherical surface. The outer side surface of the backward nozzle comprises a first circular arc conical surface, a first conical surface and a second conical surface which are smoothly connected in sequence. The backward nozzle is provided with an internal flow channel and a plurality of second nozzle holes which are sequentially connected by a third flow guide cone hole, a third straight-through hole and a fourth straight-through hole. The flow channel side surface of the internal flow channel comprises a second circular arc conical surface and a third conical surface which are smoothly connected in sequence. Compared with a conventional nozzle, the nozzle structure provided by the application can reduce the pressure drop of the nozzle during operation, improve the efficiency of rock shooting of the nozzle, and optimize the size of the nozzle. Furthermore, the nozzle can more easily realize radial turning and complete drilling.

Description

Technical Field

[0001] This invention relates to the field of oil and gas development technology, and in particular to a nozzle, a forward nozzle, a backward nozzle, and related applications. Background Technology

[0002] Due to the complex geological conditions of coalbed methane and the poor permeability of coal seams, surface extraction of coalbed methane is not effective in some coalfields, resulting in low gas production per well and failing to achieve the goal of commercial development. Therefore, in the secondary development of oil and gas wells, radial drilling is usually adopted to increase the coalbed methane production per well.

[0003] In coalbed methane production, radial drilling has the following functions: (1) it increases the exposed area of ​​the coal seam and improves coalbed methane production; (2) it increases the well spacing and reduces the number of wells and costs; (3) it overcomes the disadvantage that traditional directional drilling vertical holes cannot be reused. Radial drilling can drill one or more radial holes in different coal seams within the same vertical hole, improving the utilization efficiency of surface boreholes; (4) it can use radial holes to approach the predetermined target area in areas that cannot be accessed on the surface; (5) water jet drilling radial wells can connect coal seam fractures, improve the permeability of the coal seam, and thus increase coalbed methane production.

[0004] In the oilfield development industry, waterjet drilling is commonly used for radial well drilling, a technique that significantly enhances production in low-permeability reservoirs and near-wellbore contaminated zones. Current waterjet drilling techniques can drill radial orifices with diameters ranging from 25mm to 35mm in the formation surrounding the oil and gas well. Depending on operational needs, multiple similar radial orifices can be drilled in a single formation or in different formations. These orifices establish effective connectivity between the wellbore and the oil and gas reservoir, improving reservoir flowability, eliminating the adverse effects of near-wellbore contamination and pressure drop, and increasing single-well production. Common nozzle types used in waterjet drilling radial well operations include single-hole, multi-hole, swirling, rotating, and oscillating nozzles. Summary of the Invention

[0005] The inventors have discovered that commonly used nozzles in waterjet radial drilling operations experience significant local pressure loss as the high-pressure jet exits the nozzle, reducing the water power for rock breaking, slowing the drilling speed, and limiting the drilling distance. This hinders the jet's ability to penetrate harder formations, ultimately impacting the effectiveness of radial drilling operations. Furthermore, some nozzles, designed to enhance rock breaking efficiency and drilling performance, have complex internal flow channel structures and large dimensions, making radial turning during drilling difficult and preventing the completion of radial boreholes. Therefore, optimizing the existing nozzle structure to reduce pressure drop during use and facilitate radial turning during drilling is essential.

[0006] In view of the above problems, the present invention is proposed to provide a nozzle, a forward nozzle, a backward nozzle, and related applications that overcome or at least partially solve the above problems.

[0007] In a first aspect, embodiments of the present invention provide a forward nozzle, wherein the first end of the forward nozzle 1 has a first spherical surface 11 and the second end is a circular arc cone 12, and the forward nozzle 1 includes a plurality of first spray holes extending from the first spherical surface 11 to the side of the circular arc cone 12.

[0008] The generatrix of the arc cone 12 is an arc concave to its center line;

[0009] The first nozzle includes a first guide cone hole 13, a first through hole 14, and a second guide cone hole 15 connected in sequence. The diameters of the first guide cone hole 13 and the second guide cone hole 15 are minimized at the intersection with the first through hole 14.

[0010] In some alternative embodiments, the centerline of the first nozzle is not parallel to the centerline of the forward nozzle, and intersects the outside of the arc cone 12.

[0011] In some optional embodiments, the centerline of the first nozzle makes an angle of 8° to 12° with the centerline of the forward nozzle.

[0012] In some optional embodiments, the first nozzle further includes a second through hole 16 located outside the second guide cone hole 15, the second through hole 16 and the second guide cone hole 15 forming a stepped hole.

[0013] In some alternative embodiments, a plurality of the first nozzles are arranged in a circular array centered on the centerline of the forward nozzle.

[0014] In some optional embodiments, the generatrix of the arc cone 12 includes a section of arc with equal diameter, or a section of arc with gradually changing diameter, or multiple sections of arc with equal diameter and unequal diameter, with a smooth transition between adjacent arcs of equal diameter.

[0015] In some optional embodiments, the forward nozzle 1 has external threads to connect to the backward nozzle 2; the outer end of the forward nozzle 1 is provided with a mounting hole 17, which is an internal hexagonal hole.

[0016] Secondly, embodiments of the present invention provide a rearward nozzle, wherein the front end of the rearward nozzle 2 has a second spherical surface 21, and the outer surface of the rearward nozzle 2 includes at least a first arcuate conical surface 23, a first conical surface 24 and a second conical surface 25 with smooth transitions. The rearward nozzle 2 is provided with an internal flow channel and a plurality of second nozzle holes that penetrate the internal flow channel from the first conical surface 24.

[0017] The side surface of the internal flow channel includes a second arc conical surface 28 and a third conical surface 29 that are smoothly connected in sequence;

[0018] The second nozzle includes a third guide cone hole 210 and a third through hole 211 connected in sequence, wherein the diameter of the third guide cone hole 210 is the smallest at the intersection with the third through hole 211;

[0019] The diameter of the end with the largest rotation diameter of the first circular arc conical surface 23 is greater than the diameter of the end with the largest rotation diameter of the second circular conical surface 25.

[0020] In some optional embodiments, the outer surface of the rearward nozzle 2 further includes: a first cylindrical surface 22 located between the first arcuate conical surface 23 and the second spherical surface 21, and a second cylindrical surface 26 connected to the second conical surface 25, wherein the diameter of the first cylindrical surface 22 is larger than the diameter of the second cylindrical surface 26.

[0021] In some optional embodiments, the flow channel side of the internal flow channel further includes: a third cylindrical surface 27 connected to the second arc conical surface 28, and a third arc conical surface 213 and a fourth cylindrical surface 214 sequentially connected to the third conical surface 29.

[0022] In some optional embodiments, the centerline of the second nozzle makes an angle of 28° to 32° with the centerline of the rearward nozzle 2, and intersects at one end near the second spherical surface 21 of the rearward nozzle.

[0023] In some optional embodiments, the second nozzle further includes a fourth through hole 212 located outside the third through hole 211, the fourth through hole 212 and the third through hole 211 forming a stepped hole.

[0024] In some alternative embodiments, a plurality of the second nozzles are arranged in a circular array centered on the centerline of the rearward nozzle 2.

[0025] In some alternative embodiments, the first conical surface 24 is perpendicular to the centerline of the second nozzle; and / or the first conical surface 24 and the third conical surface 29 are parallel.

[0026] In some alternative embodiments, the angle between the second conical surface 25 and the centerline of the rearward nozzle 2 is smaller than the angle between the centerline of the second nozzle and the centerline of the rearward nozzle 2.

[0027] In some alternative embodiments, the rearward nozzle 2 has an internal thread at its front end to connect to the forward nozzle 1; the rearward nozzle 2 has an internal thread at its rear end to connect to the pressure source nozzle.

[0028] Thirdly, embodiments of the present invention provide a nozzle, comprising: a forward nozzle 1 and a backward nozzle 2, wherein the forward nozzle 1 and the backward nozzle 2 are threadedly connected;

[0029] The forward nozzle 1 is any of the forward nozzles 1 described in the first aspect above, and / or the backward nozzle 2 is any of the backward nozzles 2 described in the second aspect above.

[0030] In some alternative embodiments, the first spherical surface 11 of the forward nozzle 1 and the second spherical surface 21 of the rear nozzle 2 have the same radius; and / or the curvature of the arc segment of the arc cone 12 of the forward nozzle away from the center line of the forward nozzle 1 is the same as the curvature of the arc segment of the second arc cone 28 of the rear nozzle near the center line of the rear nozzle 2.

[0031] In some optional embodiments, when the forward nozzle 1 and the backward nozzle 2 are connected, the first spherical surface 11 and the second spherical surface 21 form a spherical surface.

[0032] Based on the same inventive concept, this invention provides a radial drilling system, including: a radial drilling device 6, a guiding device 4, a nozzle 5, and the above-mentioned nozzle 3;

[0033] The radial drilling device 6 is connected to the continuous pipe 7;

[0034] The guide device 4 has a guide hole that turns from the axis to the radial direction;

[0035] The nozzle 5 is connected to the radial drilling device 6 and passes through the guide hole of the guide device 4;

[0036] The nozzle 3 is connected to the front end of the nozzle 5 for radial drilling.

[0037] In some alternative embodiments, the present invention also provides an application of the above-described nozzle 3 in radial drilling.

[0038] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0039] The forward nozzle provided in this embodiment of the invention has a first spherical surface at the first end, which reduces air resistance during drilling. The second end is provided with an arc cone. The forward nozzle includes a plurality of first nozzle holes that extend from the first spherical surface to the side of the arc cone. Each first nozzle hole includes a first guide cone hole, a first through hole, and a second guide cone hole that are connected in sequence. During rock breaking operations, the working fluid enters the first nozzle hole from one side of the first arc cone and is ejected from the first nozzle hole. The arc cone and the second guide cone hole guide the working fluid entering the first nozzle hole of the forward nozzle, avoiding the instability of the fluid flow caused by the rapid diffusion or narrowing of the flow channel, improving the stability of the fluid flow, reducing the eddies generated by the flow, and thus reducing the pressure drop of the forward nozzle and improving the rock breaking efficiency of the forward nozzle.

[0040] The rearward nozzle provided in this embodiment of the invention has a second spherical surface at its front end, which reduces air resistance during drilling. Its outer surface includes a smoothly transitioned first arcuate conical surface, a first conical surface, and a second conical surface. This external structure prevents the rearward nozzle from jamming against the inner wall of the turning channel during radial turns, facilitating radial turning. The diameter of the end with the largest rotation diameter of the first arcuate conical surface on the rearward nozzle is larger than the diameter of the end with the largest rotation diameter of the second conical surface, allowing the rearward nozzle to turn using the first arcuate conical surface as a support point, providing a larger turning torque to the high-pressure hose connected to the rear end of the rearward nozzle. This design facilitates smooth radial bending and feeding of the high-pressure hose; the rearward nozzle is equipped with a second nozzle for spraying the working fluid; the flow channel inside the rearward nozzle includes a second arc-shaped conical surface and a third conical surface that are smoothly connected in sequence, forming a concave space structure relative to the flow channel side, which guides the working fluid to facilitate its stable entry into the second nozzle; the first and second conical surface structures on the outer side provide spray space for the working fluid to spray; this structure can reduce the pressure drop of the working fluid during its flow and spraying process in the rearward nozzle.

[0041] When the backward nozzle has a first cylindrical surface and a second cylindrical surface, the diameter of the first cylindrical surface is larger than the diameter of the second cylindrical surface, so that the backward nozzle can turn with the first cylindrical surface as the support point, providing a larger turning torque to the high-pressure hose connected to the rear end of the backward nozzle, which facilitates the high-pressure hose to bend smoothly to complete the radial turn and feed.

[0042] The nozzle provided in this embodiment of the invention includes a forward nozzle and a backward nozzle connected by threads. After connection, the arcuate cone of the forward nozzle smoothly transitions to the internal flow channel of the backward nozzle, and its design, combined with the guide cone hole, effectively reduces the pressure drop of the nozzle. Furthermore, after the forward and backward nozzles are connected, the first spherical surface and the second spherical surface can also smoothly transition. The spherical shape at the front end reduces the air resistance experienced by the nozzle during drilling operations, making radial drilling easier. When the nozzle is working, the working fluid flows into the nozzle from the internal flow channel of the backward nozzle and is ejected from the first and second nozzle holes. The jet ejected from the first nozzle hole penetrates the formation, forming a hole of a certain size in the formation. The jet ejected from the second nozzle hole generates a sufficiently large traction force to counteract the recoil force generated by the jet from the first nozzle hole, reducing the resistance encountered by the nozzle in the formation, allowing the nozzle jet to drill a farther distance, and making the reservoir modification effect of radial drilling operations more significant.

[0043] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0044] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0045] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0046] Figure 1 This is a schematic diagram of the forward nozzle in Embodiment 1 of the present invention;

[0047] Figure 2 This is a schematic diagram of the forward nozzle B direction in Embodiment 1 of the present invention;

[0048] Figure 3 This is a schematic diagram of the rearward nozzle in Embodiment 2 of the present invention;

[0049] Figure 4 This is a cross-sectional view of the rearward nozzle along direction A in Embodiment 2 of the present invention;

[0050] Figure 5 This is a schematic diagram of the nozzle in Embodiment 3 of the present invention;

[0051] Figure 6 This is a schematic diagram of radial turning and formation drilling in an embodiment of the present invention;

[0052] Explanation of reference numerals in the attached figures:

[0053] 1-Forward nozzle, 2-Reverse nozzle, 3-Nozzle, 4-Guide device, 5-Spray pipe, 6-Radial drilling device, 7-Continuous pipe;

[0054] 11-First spherical surface, 12-Circular arc cone, 13-First guide cone hole, 14-First through hole, 15-Second guide cone hole, 16-Second through hole, 17-Mounting hole;

[0055] 21-Second spherical surface, 22-First cylindrical surface, 23-First circular arc conical surface, 24-First conical surface, 25-Second conical surface, 26-Second cylindrical surface, 27-Third cylindrical surface, 28-Second circular arc conical surface, 29-Third conical surface, 210-Third guide cone hole, 211-Third through hole, 212-Fourth through hole, 213-Third circular arc conical surface, 214-Fourth cylindrical surface. Detailed Implementation

[0056] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0057] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0058] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0059] To address the problems existing in the prior art, embodiments of the present invention provide a nozzle, a forward nozzle, a backward nozzle, and related applications. Example

[0060] This invention provides a forward nozzle, such as... Figure 1 As shown, the forward nozzle 1 has a first spherical surface 11 at its first end and a circular arc cone 12 at its second end. The forward nozzle 1 includes a plurality of first spray holes that extend from the first spherical surface 1 to the side of the circular arc cone 12. The generatrix of the circular arc cone 12 is an arc concave to its center line. The first spray holes include a first guide cone hole 13, a first through hole 14, and a second guide cone hole 15 connected in sequence. The diameters of the first guide cone hole 13 and the second guide cone hole 15 are minimized at the intersection with the first through hole 14.

[0061] like Figure 1 As shown, the first end of the forward nozzle 1 is a first spherical cap, which has a first spherical surface 11, a cylindrical middle portion, and a circular arc cone 12 at the second end. The radius of the spherical cap and the radius of the flow-guiding circular arc cone can be designed as needed. Preferably, the generatrix of the flow-guiding circular arc cone 12 is an arc with a radius of 4 mm, and the radius of the first spherical surface 11 is selected as 9 mm.

[0062] Optionally, the generatrix of the circular arc cone 12 includes a segment of an arc of equal diameter, or a segment of an arc with a gradually changing diameter, or multiple segments of arcs of equal diameter with varying diameters, with a smooth transition between adjacent arcs of equal diameter. It should be noted that the curved surface can be viewed as the trajectory of a moving line, and the moving line forming the curved surface is called the generatrix. That is, the generatrix of the aforementioned circular arc cone 12 is an arc concave towards its centerline, and the circular arc cone 12 is a cone formed by rotating its generatrix around its centerline.

[0063] The aforementioned arc-shaped cone structure serves two purposes: firstly, it guides the flow of the working fluid; secondly, the arc-shaped side surface of the arc-shaped cone 12 prevents the flow channel from rapidly expanding or narrowing, thus improving fluid flow stability, reducing eddies, and consequently lowering nozzle pressure drop. Data from fluid analysis software calculations and nozzle sample tests show that, compared to traditional nozzles, a 4mm radius arc-shaped cone can reduce nozzle pressure drop by 13%–15%.

[0064] Optionally, the first nozzle also includes a second through hole 16 located outside the second guide cone hole 15, forming a stepped hole with the second guide cone hole 15. In operation, the working fluid entering the forward nozzle 1 is guided by the first guide cone hole 13 into the first through hole 14, then flows through the second guide cone hole 15 and is ejected through the second through hole 16. The guide cone hole guides the working fluid flowing into the forward nozzle 1, preventing rapid pressure drop changes that could affect the fluid velocity and thus the injection efficiency of the forward nozzle 1 when the working fluid enters or exits the first through hole 14 due to abrupt narrowing or widening of the flow channel. Simultaneously, the first guide cone hole 13, the second guide cone hole 15, and the second through hole 16 at both ends of the first through hole 14 improve fluid flow stability, reduce eddies generated by fluid flow, and lower nozzle pressure drop. The cone angles of the first guide cone hole 13 and the second guide cone hole 15 can be designed as needed; preferably, the cone angle of the first guide cone hole 13 is 20°. The cone angle of the second guide cone 15 is 16°.

[0065] In some optional embodiments, the centerline of the first nozzle is not parallel to the centerline of the forward nozzle 1, but intersects on the outside of the arc cone 12 to achieve a better spraying effect. To ensure the working fluid smoothly enters the guide cone orifice and achieves a better spraying effect, the angle between the centerline of the first nozzle and the centerline of the forward nozzle 1 is generally 8° to 12°. Preferably, the angle between the centerline of the first nozzle and the centerline of the forward nozzle is 10°.

[0066] like Figure 2 As shown, multiple first nozzles are arranged in a circular array centered on the centerline of the forward nozzle 1. It should be noted that the number of first nozzles can be selected according to the spraying requirements; preferably, the number of first nozzles is set to 8.

[0067] In some optional embodiments, the forward nozzle 1 also has an external thread for connecting to the backward nozzle; and a mounting hole 17 is provided at the outer end of the forward nozzle 1 for installing or removing the forward nozzle 1 from the backward nozzle. Optionally, the mounting hole 17 can be configured as an internal hexagonal hole for installing or removing the forward nozzle 1 from the backward nozzle using an internal hexagonal wrench. Example

[0068] like Figure 3As shown, Embodiment 2 of the present invention provides a rearward nozzle 2. The front end of the rearward nozzle 2 has a second spherical surface 21. The outer surface of the rearward nozzle 2 includes at least a smoothly transitioned first arc conical surface 23, a first conical surface 24, and a second conical surface 25. The rearward nozzle 2 is provided with an internal flow channel and a plurality of second nozzle holes that penetrate the internal flow channel from the first conical surface 24. The flow channel side includes a second arc conical surface 28 and a third conical surface 29 that are smoothly connected in sequence. The second nozzle holes include a third guide cone hole 210 and a third through hole 211 that are connected in sequence. The diameter of the end with the largest rotation diameter of the first arc conical surface 23 is greater than the diameter of the end with the largest rotation diameter of the second conical surface 25.

[0069] The first conical surface 24 of the rearward nozzle 2 with the smallest rotation diameter is connected to the second conical surface 25 with the smallest rotation diameter. The first conical surface 24 and the second conical surface 25 form a certain angle to facilitate the setting of the second nozzle orifice and to provide an outlet space for the working fluid entering the second nozzle orifice.

[0070] The second arc conical surface 28 and the third conical surface 29 of the aforementioned rearward nozzle 2 form a certain angle, and the rotation diameter of the third cylindrical surface 27 connected to the second arc conical surface 28 is much larger than the rotation diameter of the fourth cylindrical surface 214 connected to the third conical surface 29, so that a concave structure is formed at the second arc conical surface 28 and the third conical surface 29, providing a liquid inlet space for the working fluid ejected from the second nozzle.

[0071] The aforementioned rearward nozzle 2 has a second spherical cap at its front end, which has a second spherical surface 21. Connected to the second spherical cap is a first arcuate cone, which has a first arcuate conical surface 23. Connected to the first arcuate cone is a first cone, which has a first conical surface 24. Connected to the first cone is a second cone, which has a second conical surface 25. The second cone may have a chamfer. The second spherical cap, the first arcuate cone, the first cone, and the second cone are sequentially connected to form the three-dimensional structure of the rearward nozzle.

[0072] Optionally, the outer surface of the rearward nozzle also includes a first cylindrical surface 22 located between the first arcuate conical surface 23 and the second spherical surface 21, and a second cylindrical surface 26 connected to the second conical surface 25. The arcuate conical surface is a surface formed by rotating an arcuate segment that protrudes relative to the centerline around the centerline of the rearward nozzle 2.

[0073] Optionally, the side of the internal flow channel also includes a third cylindrical surface 27 connected to the second arc conical surface 28, and a third arc conical surface 213 and a fourth cylindrical surface 214 connected in sequence to the third conical surface 29.

[0074] In some alternative embodiments, such as Figure 3As shown, the front end of the rearward nozzle 2 is a second spherical cap, which has a second spherical surface 21; connected to the second spherical cap is a first cylinder, which has a first cylindrical surface 22; connected to the first cylinder is a first arcuate cone, which has a first arcuate cone surface 23; connected to the first arcuate cone is a first cone, which has a first conical surface 24; connected to the first cone is a second cone, which has a second conical surface 25; connected to the second cone is a second cylinder, which has a second cylindrical surface 26. The second cylinder may have a chamfer. The second spherical cap, the first cylinder, the first arcuate cone, the first cone, the second cone, and the second cylinder are sequentially connected to form a three-dimensional structure of the rearward nozzle, which is hollow inside and includes an internal flow channel and a threaded hole. Preferably, the cone angle of the first conical surface 24 is 120°, the cone angle of the second conical surface 25 is 20°, and the cone angle of the third conical surface 29 is 120°.

[0075] Optionally, the second nozzle includes a third guide cone orifice 210, a third through-hole 211, and a fourth through-hole 212 located outside the third through-hole 211, connected in sequence. The diameter of the third guide cone orifice 210 is smallest at its intersection with the third through-hole 211; and the fourth through-hole 212 forms a stepped orifice with the third through-hole 211. This structure can guide the working fluid entering the second nozzle and reduce the pressure drop of the working fluid flowing through the third through-hole 211. Preferably, the cone angle of the third guide cone orifice 210 is 20°.

[0076] In the aforementioned rearward nozzle, the diameter of the end with the largest rotation diameter of the first arc conical surface 23 is larger than the diameter of the end with the largest rotation diameter of the second conical surface 25, so that the rearward nozzle 2 makes radial turns with the arc conical surface 23 as the support point. When the rearward nozzle includes a first cylindrical surface 22 and a second cylindrical surface 26, the diameter of the first cylindrical surface 22 is larger than the diameter of the second cylindrical surface 26, so that the rearward nozzle 2 makes radial turns with the first cylindrical surface 22 as the support point. When the rearward nozzle 2 is working, a flexible high-pressure hose made of braided steel wire is connected to its rear end. During radial turns, the hose applies a certain thrust to the rearward nozzle 2, causing the second spherical surface 21 and the first cylindrical surface 22 at the front end of the rearward nozzle 2 to contact the inner wall of the turning channel, generating a turning torque. The hose will then bend to form an initial turn. During the turn, a high-pressure jet is ejected from the second nozzle hole on the rearward nozzle 2, generating a jet reaction force, which also forms a turning torque on the hose, further increasing the turning force of the hose, so that the rearward nozzle and the hose complete the radial turn together. When the rearward nozzle 2 turns, the first cylindrical surface 22 remains in contact with the radial turning channel, providing support. Furthermore, using the first cylindrical surface 22 as a fulcrum for turning results in a longer lever arm. With a smaller normal force (frictional resistance) generated at the contact surface, this provides a larger turning torque to the high-pressure hose connected to the rear end of the rearward nozzle 2, facilitating smooth radial turning and feeding of the high-pressure hose. In contrast, the second cylindrical surface 26 is closer to the hose connection point; using this as a fulcrum for turning can easily cause a sharp bend in the hose, affecting turning efficiency. Additionally, the front end of the rearward nozzle 2 is spherical with a rounded conical transition, preventing jamming with the inner wall of the turning channel during radial turning, thus facilitating the turn. Preferably, the diameter of the first cylindrical surface 22 is 18mm.

[0077] like Figure 4 As shown, the second nozzles are arranged in a circular array with the centerline of the rear nozzle 2 as the center. The angle between the centerline of the second nozzle and the centerline of the rear nozzle 2 is 28°~32°, and they intersect at one end near the second spherical surface 21 of the rear nozzle. Optionally, the number of second nozzles can be selected according to process requirements. Preferably, the angle between the centerline of the second nozzle and the centerline of the rear nozzle 2 is 30°, and the number of second nozzles is selected as 12.

[0078] Optionally, the first conical surface 24 is perpendicular to the centerline of the second nozzle; and / or the first conical surface 24 and the third conical surface 29 are parallel, so that when the working fluid enters and exits the second nozzle, the jet can be more concentrated to avoid jet dispersion. This structural design that ensures jet concentration can increase the jetting power of the rear nozzle 2 compared to the case of jet dispersion, thereby reducing the traction force on the front nozzle and improving the rock breaking effect.

[0079] Optionally, the angle between the second conical surface 25 and the centerline of the rearward nozzle 2 is smaller than the angle between the centerline of the second nozzle and the centerline of the rearward nozzle 2. After the working fluid is sprayed out from the second nozzle, it will diffuse to a certain extent. The water flow diffusion process will have a certain cone angle. This structure can avoid impacting the second conical surface 25 during the diffusion of the working fluid in all directions, so as to reduce the impact splash caused by the second conical surface 25 on the working fluid. Otherwise, it will reduce the jet traction force of the rearward nozzle 2 on the forward nozzle, thereby reducing the radial turning force and affecting the radial turning effect.

[0080] An internal thread is provided at the third cylindrical surface 27 at the front end of the rear nozzle 2 to connect to the front nozzle 1; an internal thread is provided at the fourth cylindrical surface 214 at the rear end of the rear nozzle 2 to connect to the pressure source nozzle pipe so that the working fluid enters the internal flow channel of the rear nozzle 2 through the pressure source nozzle pipe. Example

[0081] Embodiment 3 of the present invention provides a nozzle, including the forward nozzle 1 provided in Embodiment 1 and the backward nozzle 2 provided in Embodiment 2. For example... Figure 5 As shown, the forward nozzle 1 and the backward nozzle 2 are connected by threads. The first spherical surface 11 of the forward nozzle 1 and the second spherical surface 21 of the backward nozzle 2 have the same radius. In the connected state, the first spherical surface 11 and the second spherical surface 21 form a spherical surface.

[0082] The curvature of the arc segment of the forward nozzle 12 away from the center line of the forward nozzle 1 is the same as the curvature of the arc segment of the second arc segment of the backward nozzle 28 near the center line of the backward nozzle 2. That is, the arc segment 12 in the nozzle is smoothly connected to the internal flow channel of the forward nozzle to guide the flow of fluid, avoid the flow channel from spreading or narrowing sharply, improve the stability of fluid flow, reduce the eddies generated by the flow, and thus reduce the nozzle pressure drop.

[0083] The nozzle 3 provided in this embodiment makes radial turns with the first cylindrical surface 22 as the support point, and the connection between the forward nozzle 1 and the rearward nozzle 2 makes the overall appearance of the nozzle 3 transition between a spherical surface and an arc conical surface. The nozzle will not get stuck with the inner wall of the turning channel when making radial turns, which facilitates radial turns.

[0084] Optionally, based on the calculated values ​​from fluid analysis software and the test data from nozzle samples, in the preferred case, the diameters of the first spherical surface 11, the second spherical surface 21, and the first cylindrical surface 22 are all equal, at 18 mm; the cone angle of the first conical surface 24 is 120°, the cone angle of the second conical surface 25 is 20°, the cone angle of the third conical surface 29 is 120°, the cone angle of the first guide cone 13 is 20°, the cone angle of the second guide cone 15 is 16°, and the cone angle of the third guide cone 210 is 20°; the first nozzles are evenly arranged in groups of 8 along the centerline of the forward nozzle 1, with the angle between their centerlines and the centerline of the forward nozzle 1 being 10°; the second nozzles are evenly arranged in groups of 12 along the centerline of the backward nozzle 2, with the angle between their centerlines and the centerline of the backward nozzle 2 being 30°. At this time, the arc cone 12 can reduce the nozzle pressure drop by 13% to 15%. The structure in which the arc cone 12 is smoothly connected to the internal flow channel of the forward nozzle 1 can reduce the nozzle pressure drop by 3%. The forward nozzle 1 is provided with a second guide cone hole 15, which can reduce the nozzle pressure drop by 2%. The above optimized structure can guide the working fluid flowing through the nozzle, avoid the flow channel from spreading or narrowing sharply, improve the stability of fluid flow, reduce the eddies generated by the flow, and comprehensively reduce the nozzle pressure drop by 18% to 20%, thereby improving the efficiency of the nozzle jet rock breaking.

[0085] The nozzle provided in this invention is used for radial well drilling operations using water jets. Two factors affect the efficiency of radial drilling operations: the efficiency of the nozzle's jet rock-breaking ability and the nozzle's ability to complete radial turning maneuvers. The nozzle provided in this invention, by optimizing the internal flow channel structure and designing a guide arc cone and guide cone orifice, reduces nozzle pressure drop, enhances the nozzle's jet rock-breaking ability, and increases radial drilling efficiency and drilling depth. Furthermore, by optimizing the nozzle's external shape and dimensions, the nozzle can easily achieve radial turning and complete formation drilling, further improving the efficiency of radial well drilling operations.

[0086] The nozzle provided in this embodiment of the invention has a smaller pressure drop compared to traditional nozzles, resulting in less energy loss when the same injection power is required. This means that less power equipment is needed for radial drilling operations, which can save energy and reduce oilfield extraction costs to some extent.

[0087] The nozzle provided in this embodiment of the invention reduces the pressure drop of the nozzle when drilling radial wells, which not only improves rock breaking power, drilling distance and operation effect, but also expands the diameter of the wellbore to a certain extent, thus better improving the oilfield exploitation effect.

[0088] Based on the same inventive concept, such as Figure 6 As shown, this embodiment of the invention also provides a radial drilling system, including: a radial drilling device 6, a guiding device 4, a nozzle 5, and a nozzle 3.

[0089] Radial drilling device 6 is connected to continuous pipe 7;

[0090] The guide device 4 has a guide hole that turns from axial to radial;

[0091] The nozzle 5 is connected to the radial drilling device 6 and passes through the guide hole of the guide device;

[0092] Nozzle 3 is connected to the front end of nozzle 5 for radial drilling.

[0093] During waterjet drilling of radial wells, the following steps are first performed: First, a conventional tubing is connected to the guiding device 4, which is then lowered into the wellbore and positioned using a locating anchor. Next, a coiled tubing 7 is connected to the casing drilling window tool, which is lowered into the guiding device 4 for casing window opening. Finally, the coiled tubing 7 is connected to the radial drilling device 6, which is lowered into the guiding device 4 and then pumped with high-pressure working fluid through a surface pump unit to the radial drilling tool inside the wellbore. The working fluid enters the nozzle 3 through the nozzle pipe 5 connected to the radial drilling device 6, allowing the jet from the forward nozzle to penetrate the formation and form a 25mm–35mm diameter hole. During the jetting process, the jet from the backward nozzle rounds and further enlarges the diameter of the hole penetrated by the forward nozzle, making the formed channel more conducive to the connection between the reservoir and the wellbore, thus completing the radial drilling operation.

[0094] Based on the same inventive concept, embodiments of the present invention also provide the application of the above-described forward nozzle, the above-described backward nozzle, or the above-described nozzle in radial drilling.

[0095] It should be noted that the nozzle described in the embodiments of the present invention is not limited to use with a continuous tubing machine, but can also be used with a hollow polished rod. It is not only applicable to waterjet drilling radial well operations, but also to other working scenarios such as pipeline cleaning, descaling, and jet cutting.

[0096] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0097] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0098] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A forward-facing nozzle, characterized in that, The forward nozzle (1) has a first spherical surface (11) at one end and a circular arc cone (12) at the other end. The forward nozzle (1) includes a plurality of first spray holes that extend from the first spherical surface (11) to the side of the circular arc cone (12). The generatrix of the circular arc cone (12) is an arc concave to its center line; The first nozzle includes a first guide cone hole (13), a first through hole (14), and a second guide cone hole (15) connected in sequence. The diameters of the first guide cone hole (13) and the second guide cone hole (15) are minimized at the intersection with the first through hole (14). The centerline of the first nozzle is not parallel to the centerline of the forward nozzle, and intersects on the outside of the arc cone (12); The angle between the centerline of the first nozzle and the centerline of the forward nozzle is 8°~12°; The first nozzle also includes a second through hole (16) located outside the second guide cone hole (15), and the second through hole (16) and the second guide cone hole (15) form a stepped hole.

2. The forward nozzle as described in claim 1, characterized in that, The plurality of first nozzles are arranged in a circular array centered on the centerline of the forward nozzle.

3. The forward nozzle as described in claim 1, characterized in that, The generatrix of the arc cone (12) includes a section of arc with equal diameter, or a section of arc with gradually changing diameter, or multiple sections of arc with equal diameter of unequal diameter, with a smooth transition between adjacent arcs of equal diameter.

4. The forward nozzle as described in any one of claims 1-3, characterized in that, The forward nozzle (1) has an external thread for connecting to the backward nozzle (2); the outer end of the forward nozzle (1) is provided with a mounting hole (17), which is an internal hexagonal hole.

5. A rearward nozzle, characterized in that, The rearward nozzle (2) has a second spherical surface (21) at its front end. The outer surface of the rearward nozzle (2) includes at least a first arc conical surface (23), a first conical surface (24), and a second conical surface (25) with smooth transitions. The rearward nozzle (2) is provided with an internal flow channel and a plurality of second nozzle holes that penetrate the internal flow channel from the first conical surface (24). The side of the internal flow channel includes a second circular arc cone surface (28) and a third circular cone surface (29) that are smoothly connected in sequence. The second nozzle includes a third guide cone hole (210) and a third through hole (211) connected in sequence. The diameter of the third guide cone hole (210) is the smallest at the intersection with the third through hole (211). The diameter of the end with the largest rotation diameter of the first arc conical surface (23) is greater than the diameter of the end with the largest rotation diameter of the second arc conical surface (25); The outer surface of the rearward nozzle (2) further includes: a first cylindrical surface (22) located between the first arc conical surface (23) and the second spherical surface (21), and a second cylindrical surface (26) connected to the second conical surface (25), wherein the diameter of the first cylindrical surface (22) is greater than the diameter of the second cylindrical surface (26); The centerline of the second nozzle makes an angle of 28°~32° with the centerline of the rear nozzle (2), and they intersect at one end near the second spherical surface (21) of the rear nozzle; The second nozzle also includes a fourth through hole (212) located outside the third through hole (211), the fourth through hole (212) and the third through hole (211) forming a stepped hole.

6. The rearward nozzle as described in claim 5, characterized in that, The side of the internal flow channel also includes: a third cylindrical surface (27) connected to the second arc conical surface (28), a third arc conical surface (213) and a fourth cylindrical surface (214) connected in sequence to the third conical surface (29).

7. The rearward nozzle as described in claim 5, characterized in that, Multiple second nozzles are arranged in a circular array with the center line of the rearward nozzle (2) as the center.

8. The rearward nozzle as described in claim 5, characterized in that, The first conical surface (24) is perpendicular to the centerline of the second nozzle; and / or the first conical surface (24) and the third conical surface (29) are parallel.

9. The rearward nozzle as described in claim 5, characterized in that, The angle between the second conical surface (25) and the center line of the rear nozzle (2) is smaller than the angle between the center line of the second nozzle and the center line of the rear nozzle (2).

10. The rearward nozzle as described in any one of claims 5-9, characterized in that, The rear nozzle (2) has an internal thread at its front end to connect to the front nozzle (1); the rear nozzle (2) has an internal thread at its rear end to connect to the pressure source nozzle.

11. A nozzle, characterized in that, include: A forward nozzle (1) and a backward nozzle (2) are threaded together; The forward nozzle (1) is the forward nozzle (1) according to any one of claims 1-4, and / or the backward nozzle (2) is the backward nozzle (2) according to any one of claims 5-10.

12. The nozzle as claimed in claim 11, characterized in that, The first spherical surface (11) of the forward nozzle (1) and the second spherical surface (21) of the backward nozzle (2) have the same radius; and / or the curvature of a segment of the arc of the arc cone (12) of the forward nozzle away from the center line of the forward nozzle (1) is the same as the curvature of a segment of the arc of the second arc cone (28) of the backward nozzle near the center line of the backward nozzle (2).

13. The nozzle as claimed in claim 12, characterized in that, When the forward nozzle (1) and the backward nozzle (2) are connected, the first spherical surface (11) and the second spherical surface (21) form a spherical surface.

14. A radial drilling system, characterized in that, include: Radial drilling device (6), guide device (4), nozzle (5) and nozzle (3) as described in any one of claims 11-13; The radial drilling device (6) is connected to the continuous pipe (7); The guide device (4) has a guide hole that turns from the axis to the radial direction; The nozzle (5) is connected to the radial drilling device (6) and passes through the guide hole of the guide device (4); The nozzle (3) is connected to the front end of the nozzle pipe (5) for radial drilling.

15. The application of a forward nozzle (1) as described in any one of claims 1-4, a backward nozzle (2) as described in any one of claims 5-10, or a nozzle (3) as described in any one of claims 11-13 in radial drilling.

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