A fluidic pulse generator

Abstract

The application provides a kind of jet pulse generator, comprising: the shell is configured as cylindrical;Wall jet element is arranged in the shell;Split-flow hydraulic cylinder is installed in the lower end of wall jet element, the split-flow hydraulic cylinder is configured to include main cavity, first flow channel and second flow channel are communicated respectively;Impact assembly is arranged in the main cavity, the impact assembly divides the main cavity into upper liquid chamber and lower liquid chamber, the first flow channel and the second flow channel are communicated with the upper liquid chamber and the lower liquid chamber respectively;And impact base is fixed in the lower end of split-flow hydraulic cylinder;Wherein, liquid flowing through the wall jet element can enter the first flow channel and the second flow channel alternately in turn, to drive the impact assembly reciprocating motion along the main cavity, to generate pulse pressure, and can make the impact assembly impact on the impact base.

Description

Technical Field

[0001] This invention belongs to the field of petroleum engineering drilling technology, specifically, it relates to a jet pulse generator. Background Technology

[0002] In extended reach wells and horizontal wells, due to the large inclination angle, most of the drill string's weight presses against the wellbore in the inclined section, resulting in high friction between the tubing and the wellbore. This leads to dragging pressure and increased torque, causing discontinuous or limited drilling pressure transmitted to the drill bit. With the increasing number of extended reach wells and the continuous extension of horizontal displacement, problems such as increased friction and dragging pressure, and ineffective drilling pressure transmission arise during drilling. This reduces the mechanical rate of penetration, decreases horizontal reach, and may even prevent drilling to the designed well depth. During drilling operations, relying solely on the weight of the drill string in the vertical section is insufficient to advance the tubing, making tool face control difficult and limiting the length of the horizontal section reached, resulting in low operational efficiency.

[0003] In existing technologies, an oscillator is typically formed by introducing a pressure pulse generating tool and a matching axial vibration generating tool into the downhole tubing. Pressure pulses are generated by periodically changing the fluid flow area. These pressure pulses act on the matching axial vibration generating tool, driving the drill string to produce axial creep, reducing the friction coefficient between the tubing and the well wall during sliding drilling, reducing the frictional resistance of the tubing, eliminating drill string pressure drag, improving the drilling pressure transmission effect, and increasing the efficiency of directional drilling.

[0004] A hydraulic oscillator is a specialized tool for reducing friction and resistance, typically consisting of a pulse generator and a vibration generator. Currently, common pulse generators generally utilize screws or turbines to drive eccentric valve discs to generate hydraulic pulses. The valve discs of pulse generators operating on this principle are prone to erosion, damage, and failure, severely impacting the tool's effectiveness in reducing friction and preventing pressure buildup in later stages of use. Summary of the Invention

[0005] To address the technical problems described above, this invention aims to provide a jet pulse generator that can generate pulse pressure and cause axial creep in the drill string, thereby converting static friction into dynamic friction. This is highly beneficial for reducing friction between the wellbore and the drill string during sliding and rotary drilling, and can significantly improve mechanical drilling speed and horizontal well extension capability.

[0006] To this end, the present invention provides a jet pulse generator, comprising: a cylindrical housing; a wall-mounted jet element disposed within the housing; a flow-dividing hydraulic cylinder mounted at the lower end of the wall-mounted jet element, the flow-dividing hydraulic cylinder being configured to include a main cavity, a first flow channel and a second flow channel respectively communicating with the main cavity; an impact assembly disposed within the main cavity, the impact assembly dividing the main cavity into an upper liquid cavity and a lower liquid cavity, the first flow channel and the second flow channel respectively communicating with the upper liquid cavity and the lower liquid cavity; and an impact base fixed at the lower end of the flow-dividing hydraulic cylinder; wherein, liquid flowing through the wall-mounted jet element can sequentially and alternately enter the first flow channel and the second flow channel to drive the impact assembly to reciprocate along the main cavity, thereby generating pulse pressure and enabling the impact assembly to impact the impact base.

[0007] In one embodiment, the inlet ends of the first flow channel and the second flow channel are located on the same axial end face of the diverting hydraulic cylinder, and are respectively connected to the first liquid outlet and the second liquid outlet of the wall-mounted jet element.

[0008] In one embodiment, the first flow channel is configured to extend axially to communicate with the upper space of the main cavity.

[0009] In one embodiment, the second flow channel extends axially to communicate with the lower space of the main cavity.

[0010] The second flow channel is configured to include an inclined channel and a straight channel communicating with the inclined channel, and the straight channel is formed within the side wall of the flow-dividing hydraulic cylinder.

[0011] In one embodiment, the impact assembly includes an impact rod and a piston fixedly mounted on the impact rod. The piston forms a sliding seal with the side wall of the main cavity, and the piston can drive the impact rod to reciprocate under the action of liquid pressure.

[0012] In one embodiment, a flow guide cap is provided at the upper end of the wall-attached jet element, the flow guide cap being used to guide liquid to the inlet of the wall-attached jet element.

[0013] In one embodiment, the outer casing is provided with an upper connector and a lower connector at both ends, the upper connector being used to connect to the upper tubing string and the lower connector being used to connect to the lower drilling tool.

[0014] In one embodiment, a gasket is installed between the lower end face of the upper connector and the upper end face of the flow guide cap.

[0015] In one embodiment, an adjusting sleeve is installed between the lower connector and the impact base, with the upper and lower end faces of the adjusting sleeve abutting against the lower end face of the impact base and the upper end face of the lower connector, respectively.

[0016] In one embodiment, the impact base is configured to include a cylindrical body portion and an annular protrusion formed on the outer peripheral surface of the body portion.

[0017] The main body is inserted into the main cavity and forms a seal. The upper and lower end faces of the annular protrusion abut against the lower end face of the diverting hydraulic cylinder and the upper end face of the adjusting sleeve, respectively. The impact base can transmit the impact force generated by the impact assembly to the upper tubing and the lower drill string.

[0018] Compared with the prior art, the advantages of this application are:

[0019] The jet-type pulse generator according to the present invention can generate pulse pressure and induce axial creep in the drill string, thereby converting static friction into dynamic friction. This is highly beneficial for reducing friction between the wellbore and drill pipe during sliding and rotary drilling, significantly improving pressure on the drill bit, increasing directional drilling efficiency, and significantly enhancing mechanical drilling rate and horizontal well extension capability, thus greatly improving drilling efficiency and drilling operation results. Compared with common pulse generators that use screws and turbines to drive eccentric valve disc assemblies to generate hydraulic pulses, this jet-type pulse generator can significantly increase the pulse pressure it generates and has good erosion resistance. Attached Figure Description

[0020] The present invention will now be described with reference to the accompanying drawings.

[0021] Figure 1 The structure of the jet pulse generator according to the present invention is shown.

[0022] Figure 2 Showing Figure 1 The state of the impact component in the jet pulse generator shown is when it moves upward to the highest point of its stroke.

[0023] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0024] The invention will now be described with reference to the accompanying drawings.

[0025] In this application, it should be noted that the end of the jet pulse generator according to the present invention that is lowered into the wellbore near the wellhead is defined as the upper end or a similar term, while the end that is farther from the wellhead is defined as the lower end or a similar term. It should also be noted that the directional terms or limiting words such as "upper" and "lower" used in this application are all specific to the referenced appendix. Figure 1 In other words, they are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0026] Figure 1 The structure of the jet pulse generator 100 according to the present invention is shown. In practical applications, the jet pulse generator 100 is connected in the drilling string, with the upper end of the jet pulse generator 100 connected to a vibration generating tool (not shown) via the string, and the lower end connected to the drill pipe or lower drilling tool (not shown).

[0027] like Figure 1 As shown, the jet pulse generator 100 includes a cylindrical housing 1, a wall-attached jet element 2 installed inside the housing 1, a flow-dividing hydraulic cylinder 3, an impact assembly 4 disposed inside the flow-dividing hydraulic cylinder 3, and an impact base 5 fixed to the lower end of the flow-dividing hydraulic cylinder 3. During operation, the liquid flowing through the wall-attached jet element 2 drives the impact assembly 4 to reciprocate, generating pulse pressure. This pressure causes the impact assembly 4 to impact the impact base 5, which is then transmitted to the drill string and other drilling tools connected to the jet pulse generator 100. Thus, the jet pulse generator 100 can induce axial creep in the drill string, converting static friction into dynamic friction. This is highly beneficial for reducing friction between the wellbore and drill pipe during sliding and rotary drilling, significantly improving mechanical drilling speed and horizontal well extension capability, and greatly enhancing drilling efficiency and drilling performance. In addition, the pulses generated by the jet pulse generator 100 can act on the vibration generating tool connected to the upper end of the jet pulse generator 100, causing the vibration generating tool to vibrate, further reducing friction and resistance.

[0028] like Figure 1 As shown, an upper connector 6 and a lower connector 7 are fixedly connected to the upper and lower ends of the outer casing 1, respectively. The upper connector 6 is used to connect to the upper tubing string, and the lower connector 7 is used to connect to the lower drilling tool. In one embodiment, both the upper connector 6 and the lower connector 7 are fixedly connected to the outer casing 1 by means of threaded connection.

[0029] exist Figure 1In the illustrated embodiment, both ends of the outer casing 1 are configured with negative conical connecting buckles, and the lower end of the upper connector 6 is configured with a positive conical connecting buckle. The upper connector 6 and the upper end of the outer casing 1 are fixedly connected by the positive and negative conical connecting buckles. The upper end of the upper connector 6 is fixedly connected to the upper tubing string by the negative conical connecting buckle. Similarly, both ends of the lower connector 7 are configured with positive conical connecting buckles, and the lower connector 7 and the lower end of the outer casing 1 are fixedly connected by the positive and negative conical connecting buckles. The lower end of the lower connector 7 is fixedly connected to the lower drill string by the positive conical connecting buckle. This connection structure of the upper connector 6 and the lower connector 7 is very beneficial for ensuring the connection stability between the outer casing 1 and the upper tubing string and the lower drill string, and is also convenient and quick to install.

[0030] In this embodiment, the lower end of the upper connector 6 is inserted into the outer casing 1, thereby forming a first step with the lower end face of the upper connector 6 facing downwards on the inner wall of the outer casing 1 near the upper end. Similarly, the upper end of the lower connector 7 is inserted into the outer casing 1, thereby forming a second step with the upper end face of the lower connector 7 facing upwards on the inner wall of the outer casing 1 near the lower end. The functions of the first and second steps will be described below.

[0031] like Figure 1 As shown, a flow guide cap 20 is provided at the upper end of the wall-mounted jet element 2. The flow guide cap 20 is used to guide the liquid to the inlet 21 of the wall-mounted jet element 2. The interior of the flow guide cap 20 has a stepped hole, with the large-diameter end of the stepped hole facing upward and communicating with the upper connector 6, and the small-diameter end of the stepped hole facing downward and communicating with the inlet 21 of the wall-mounted jet element 2. The upper and lower end faces of the flow guide cap 20 respectively abut against the first step and the upper end face of the wall-mounted jet element 2, thereby forming an axial constraint. This structure of the flow guide cap 20 is very advantageous for guiding the liquid from the upper tubing into the wall-mounted jet element 2.

[0032] In one embodiment, a gasket 8 can be installed between the lower end face (first step) of the upper connector 6 and the upper end face of the guide cap 20. The gasket 8 can serve as an adjustment element during installation, facilitating installation. Simultaneously, the gasket 8 also helps ensure the seal between the upper connector 6 and the housing 1.

[0033] According to the present invention, the diverting hydraulic cylinder 3 is installed at the lower end of the wall-mounted jet element 2, and the upper end face of the diverting hydraulic cylinder 3 is in close contact with the lower end face of the wall-mounted jet element 2.

[0034] like Figure 1 As shown, the flow-dividing hydraulic cylinder 3 is constructed in a cylindrical shape. Inside the flow-dividing hydraulic cylinder 3, there is a main cavity 31, a first flow channel 32, and a second flow channel 33. The first flow channel 32 and the second flow channel 33 are respectively connected to the main cavity 3. The inlet ends of the first flow channel 32 and the second flow channel 33 are located on the same axial end face of the flow-dividing hydraulic cylinder 3. Figure 1The first flow channel 32 is located on the upper surface of the wall-mounted jet element 2, and its inlet end is connected to the first outlet 22 of the wall-mounted jet element 2. The inlet end of the second flow channel 33 is connected to the second outlet 23 of the wall-mounted jet element 2. Preferably, the inlet ends of the first flow channel 32 and the second flow channel 33 can be arranged to be radially opposite to each other.

[0035] The first flow channel 32 is configured to extend axially to communicate with the upper space of the main cavity 31.

[0036] The second flow channel 33 extends axially to communicate with the lower space of the main cavity 31. The second flow channel 33 is configured to include an inclined channel 331 and a straight channel 332 communicating with the inclined channel 331, and the straight channel 332 is formed in the side wall of the diverting hydraulic cylinder 3.

[0037] According to the present invention, the impact assembly 4 is arranged in the main cavity 31 of the diverting hydraulic cylinder 3, dividing the main cavity 31 into an upper liquid cavity 311 and a lower liquid cavity 312. The first flow channel 32 communicates with the upper liquid cavity 311, and the second flow channel 33 communicates with the lower liquid cavity 312. Liquid from the upper drill string flows through the wall-attached jet element 2 and, under the action of the wall-attached jet element 2, alternately enters the first flow channel 32 and the second flow channel 33, and then alternately enters the upper liquid cavity 311 and the lower liquid cavity 312, thereby causing the impact assembly 4 to reciprocate under the action of liquid pressure.

[0038] According to the present invention, the impact assembly 4 includes an impact rod 41 and a piston 42 fixedly mounted on the impact rod 41, the piston 42 forming a sliding seal with the side wall of the main cavity 31. The axial length of the impact rod 41 is set to be less than the axial length of the main cavity 31. Thus, the upper liquid cavity 311 is formed above the upper end face of the piston 42, and the lower liquid cavity 312 is formed below the piston 42. When liquid enters the upper liquid cavity 311 through the first flow channel 32, the liquid pressure acts on the upper end face of the piston 42, pushing the piston 42 downward. When liquid enters the lower liquid cavity 312 through the second flow channel 33, the liquid pressure acts on the lower end face of the piston 42, pushing the piston 42 upward. Thus, the piston 42 can drive the impact rod 41 to reciprocate under the action of liquid pressure, thereby generating pulse pressure and causing the impact assembly 4 to impact the impact base 5. The impact base 5 can transmit the impact force generated by the impact assembly 4 to the drill string and other drilling tools connected to the jet pulse generator 100.

[0039] According to the present invention, the impact stroke of the impact assembly 4 depends on the axial movement range of the impact assembly 4 within the main cavity 31, and the impact stroke of the impact assembly 4 is the axial length of the main cavity 31 minus the axial length of the impact rod 41. The pulse amplitude and pulse frequency generated by the jet pulse generator 100 can be adjusted by adjusting the impact stroke of the impact assembly 4. This impact stroke of the impact assembly 4 can generate pulses with small amplitude and high frequency.

[0040] like Figure 1 As shown, the impact base 5 is fixed to the lower end of the hydraulic cylinder 3. An adjusting sleeve 9 is installed between the lower connector 7 and the impact base 5. The upper and lower end faces of the adjusting sleeve 9 abut against the lower end face of the impact base 5 and the upper end face (second step) of the lower connector 7, respectively. The adjusting sleeve 9 can provide limiting support for the impact base 5, thereby fixing the impact base 5 to the lower end of the hydraulic cylinder 3. At the same time, the adjusting sleeve 9 serves as an adjusting component during installation, facilitating installation.

[0041] According to one embodiment of the present invention, the impact base 5 is configured to include a cylindrical body portion 51 and an annular protrusion 52 formed on the outer peripheral surface of the body portion 51. The lower end of the hydraulic cylinder 3 is configured to be open. The body portion 51 of the impact base 5 is inserted into the lower end opening of the hydraulic cylinder 3 and forms a seal with the hydraulic cylinder 3, thereby forming a main cavity 31 between the hydraulic cylinder 3 and the impact base 5. The upper and lower end faces of the annular protrusion 52 of the impact base 5 abut against the lower end face of the hydraulic cylinder 3 and the upper end face of the adjusting sleeve 9, respectively, thereby fixing the impact base 5 between the hydraulic cylinder 3 and the adjusting sleeve 9. The impact base 5 is able to transmit the impact force generated by the impact assembly 4 sequentially through the annular protrusion 52, the adjusting sleeve 9, and the lower connector 7 to the upper tubing and the lower drill bit connected to the jet pulse generator 100.

[0042] The working process of the jet pulse generator 100 according to this invention is briefly described below. In actual operation, the liquid from the upper drill string flows through the wall-mounted jet element 2. Under the action of the wall-mounted jet element 2, the liquid alternately enters the first flow channel 32 and the second flow channel 33, and then alternately enters the upper liquid chamber 311 and the lower liquid chamber 312. The liquid pressure generated by the liquid entering the upper liquid chamber 311 and the lower liquid chamber 312 acts on the upper end face and the lower end face of the piston 42, respectively. Thus, under the action of liquid pressure, the piston 42 drives the impact assembly 4 to reciprocate. Figure 1 and Figure 2 The reciprocating motion process of impact component 4 is shown. Figure 1 The status of impact component 4 as it rises to its highest point is displayed. Figure 2 The image shows the state where the impact assembly 4 descends to impact the impact base 5. The impact assembly 4 reciprocates, periodically impacting the impact base 5, thereby generating pulse pressure. Simultaneously, the impact assembly 4 impacts the impact base 5 and can be transmitted sequentially through the impact base 5, adjusting sleeve 9, and lower connector 7 to the drill string and other drill tools connected to the jet pulse generator 100, causing the drill string to creep axially, thus converting static friction into dynamic friction, thereby reducing friction and drag. Furthermore, the pulses generated by the jet pulse generator 100 can act on the vibration generating tool connected to the upper end of the jet pulse generator 100, driving the vibration generating tool to vibrate, thereby further reducing friction and drag.

[0043] The jet pulse generator 100 according to the present invention can generate pulse pressure and induce axial creep in the drill string, thereby converting static friction into dynamic friction. This is highly beneficial for reducing friction between the wellbore and drill pipe during sliding and rotary drilling, significantly improving pressure on the drill bit, increasing directional drilling efficiency, and significantly improving mechanical drilling rate and horizontal well extension capability, thus greatly enhancing drilling efficiency and drilling operation results. Compared with common pulse generators that use screws and turbines to drive eccentric valve disc assemblies to generate hydraulic pulses, this jet pulse generator 100 can significantly increase the pulse pressure it generates and has good erosion resistance.

[0044] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 according to the specific circumstances.

[0046] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A jet pulse generator, comprising: A cylindrical outer shell (1) is provided at the lower end of the outer shell, and the lower joint (7) is used to connect the lower drill bit; The wall-mounted jet element (2) is disposed inside the housing. A flow-dividing hydraulic cylinder (3) is installed at the lower end of the attached jet element. The flow-dividing hydraulic cylinder is configured to include a main cavity (31), a first flow channel (32) and a second flow channel (33) respectively connected to the main cavity. The lower end of the main cavity is configured to be open. An impact assembly (4) is disposed in the main cavity, which divides the main cavity into an upper liquid cavity (311) and a lower liquid cavity (312). The first flow channel and the second flow channel are respectively connected to the upper liquid cavity and the lower liquid cavity. An adjusting sleeve (9) is installed at the upper end of the lower connector, the lower end face of the adjusting sleeve abutting against the upper end face of the lower connector; and An impact base (5) is fixed at the lower end of the flow-dividing hydraulic cylinder. The impact base is configured to include a cylindrical body part (51) and an annular protrusion (52) formed on the outer peripheral surface of the body part. The body part is inserted into the main cavity from the lower end of the main cavity and forms a seal. The upper end face of the annular protrusion abuts against the lower end face of the flow-dividing hydraulic cylinder and the lower end face of the annular protrusion abuts against the upper end face of the adjusting sleeve. The liquid flowing through the attached jet element can sequentially enter the first flow channel and the second flow channel to drive the impact assembly to reciprocate along the main cavity, thereby generating pulse pressure and enabling the impact assembly to impact the impact base. The impact base can transmit the impact generated by the impact assembly to the upper tubing and the lower drill string.

2. The jet pulse generator according to claim 1, characterized in that, The inlet ends of the first flow channel and the second flow channel are located on the same axial end face of the flow splitting hydraulic cylinder, and are respectively connected to the first liquid outlet (22) and the second liquid outlet (23) of the wall-mounted jet element.

3. The jet pulse generator according to claim 2, characterized in that, The first flow channel is configured to extend axially to communicate with the upper space of the main cavity.

4. The jet pulse generator according to claim 2 or 3, characterized in that, The second flow channel extends axially to communicate with the lower space of the main cavity. The second flow channel is configured to include an inclined channel (331) and a straight channel (332) communicating with the inclined channel, and the straight channel is formed in the side wall of the flow-dividing hydraulic cylinder.

5. The jet pulse generator according to any one of claims 1 to 3, characterized in that, The impact assembly includes an impact rod (41) and a piston (42) fixedly mounted on the impact rod. The piston forms a sliding seal with the side wall of the main cavity. The piston can drive the impact rod to reciprocate under the action of liquid pressure.

6. The jet pulse generator according to claim 1, characterized in that, A flow guide cap (20) is provided at the upper end of the wall-mounted jet element, which is used to guide the liquid to the inlet (21) of the wall-mounted jet element.

7. The jet pulse generator according to claim 6, characterized in that, The upper end of the outer shell is provided with an upper connector (6), which is used to connect the upper tubular column.

8. The jet pulse generator according to claim 7, characterized in that, A gasket (8) is installed between the lower end face of the upper connector and the upper end face of the flow guide cap.

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