A pressure reduction control device for oil and gas field drilling equipment

Abstract

This invention relates to a pressure reduction control device for oil and gas field drilling equipment, belonging to the field of oil and gas field drilling engineering technology. It includes an outer cylinder and an inner cylinder, with an external channel formed between the inner wall of the outer cylinder and the outer wall of the inner cylinder. An injection pipe is also provided on the side wall of the inner cylinder, vertically distributed upwards and located below the inlet. A vent hole connected to the inlet is provided on the inner cylinder. By installing the injection pipe within the external channel, the drilling fluid ejected from the injection pipe forms a jet stream. This jet stream guides the drilling fluid within the external channel, directing it towards the inlet and reducing downhole pressure. Simultaneously, due to the presence of numerous air bubbles within the jet stream, the air-lift effect of these bubbles causes the drilling fluid below the inlet to move upwards. This invention solves the technical problem of existing drilling equipment requiring periodic shutdowns to drain drilling fluid, which affects work efficiency, and the risk of excessive downhole pressure leading to formation leakage and wellbore collapse if drainage is not timely.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field drilling engineering technology, and specifically to a pressure reduction control device for oil and gas field drilling equipment. Background Technology

[0002] In existing drilling equipment, drilling fluid needs to be continuously pumped into the well during operation. The drilling fluid not only cools the drill bit, but also suppresses formation pressure and maintains wellbore stability. As drilling fluid is continuously pumped in, the downhole pressure gradually increases. To prevent excessive downhole pressure, it is usually necessary to stop the machine periodically to extract the drilling fluid and maintain the downhole pressure within a predetermined range.

[0003] However, the periodic shutdown and pumping out of drilling fluid reduces work efficiency. If the drilling fluid is not discharged from the well in time, it will cause the downhole pressure to increase continuously. If it exceeds the predetermined pressure, it may lead to formation leakage and wellbore collapse. Summary of the Invention

[0004] To address the technical problems of existing drilling equipment requiring periodic shutdowns to drain drilling fluid, which affects work efficiency, and the potential for excessive downhole pressure leading to formation leakage and wellbore collapse if drainage is not timely, this invention provides a pressure reduction control device for oil and gas field drilling equipment.

[0005] To achieve the above objectives, the specific solution adopted by the present invention is as follows: a pressure reduction control device for oil and gas field drilling equipment, comprising an outer cylinder and an inner cylinder, the inner cylinder being fixedly installed on the outer cylinder by a connecting rod, an external channel being formed between the inner wall of the outer cylinder and the outer wall of the inner cylinder, the top of the outer cylinder extending toward the inner cylinder and forming a drainage port with the outer wall of the inner cylinder, the drainage port allowing drilling fluid in the external channel to be discharged upwards, a drainage hole being provided on the side wall of the inner cylinder, a jet pipe being connected to the drainage hole, the jet pipe being vertically upwards and located below the drainage port, and a vent hole for air intake being provided on the inner cylinder, and the vent hole being connected to the drainage hole.

[0006] As an optimized solution for the pressure reduction control device applied to oil and gas field drilling equipment, the drainage hole is a through hole that is thick at both ends and thin in the middle, and the vent hole is connected to the middle section of the drainage hole.

[0007] As another optimized solution for the pressure reduction control device applied to oil and gas field drilling equipment, along the axial direction of the inner cylinder, the inner diameter of the upper section of the inner cylinder is larger than that of the lower section, and the diameter change point is a conical surface, with the drainage hole located on the conical surface.

[0008] As another optimized solution for the pressure reduction control device applied to oil and gas field drilling equipment, the angle between the conical surface and the central axis of the inner cylinder is greater than 10 degrees and less than 75 degrees.

[0009] As another optimized solution for the pressure reduction control device applied to oil and gas field drilling equipment, the injection pipe adopts a right-angle bend, and the outlet end of the injection pipe is directly opposite the drain port.

[0010] As another optimized solution for the pressure reduction control device applied to oil and gas field drilling equipment, the vent is connected to an external air pipe, and the air inlet end of the air pipe is connected to the atmosphere.

[0011] As another optimized solution for the pressure reduction control device applied to oil and gas field drilling equipment, the top of the outer cylinder is provided with an annular baffle, and a funnel-shaped channel is formed between the inner wall of the annular baffle and the outer wall of the inner cylinder, with the outlet located at the outlet end of the funnel-shaped channel.

[0012] As another optimized solution for the pressure reduction control device applied to oil and gas field drilling equipment, a guide ring is provided on the annular baffle, and a guide channel with a gradually increasing inner diameter is formed between the guide ring and the inner cylinder, with the outlet located at the inlet end of the guide channel.

[0013] Beneficial effects:

[0014] 1. The pressure reduction control device for oil and gas field drilling equipment described in this invention involves setting up a jet pipe in an external channel. The drilling fluid ejected from the jet pipe forms a jet stream. The jet stream guides the drilling fluid in the external channel to flow towards the inlet and is discharged through the inlet, reducing downhole pressure. At the same time, because the jet stream contains a large number of air bubbles, the air bubbles move upward and push the drilling fluid above the inlet upward, thereby driving the drilling fluid below the inlet to flow upward and accelerating the speed at which the drilling fluid is discharged from the inlet. That is, the speed at which the drilling fluid is discharged from the inlet is increased through the air-lifting effect.

[0015] 2. The pressure reduction control device for oil and gas field drilling equipment described in this invention has an annular plate and a guide ring on the outer cylinder. Along the direction of drilling fluid flow, that is, the drilling fluid flows from the external channel through the inlet to the guide channel. Its inner diameter gradually decreases and then gradually increases, which promotes the increase of the speed of the drilling fluid flowing out of the guide channel, forming a secondary jet effect, and guiding the drilling fluid in the external channel to be discharged from the inlet. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] In the diagram: 1. Casing, 2. Outer cylinder, 3. Inner cylinder, 4. External channel, 5. Drainage port, 6. Drainage hole, 7. Injection pipe, 8. Vent hole, 9. Air pipe, 10. Connecting rod, 11. Annular plate, 12. Guide ring, 13. Drill rod, 14. Drill bit. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The parts of the following embodiments that are not specifically described are all prior art, such as casing 1, drill pipe 13, drill bit 14, drilling fluid entering through the internal channel of drill pipe 13, passing through drill bit 14 and being discharged downhole, and being discharged through the channel between casing 1 and drill pipe 13 to form a drilling fluid circulation loop, all of which are technologies known to those skilled in the art.

[0020] like Figure 1 As shown, the present invention is a pressure reduction control device for oil and gas field drilling equipment. The device is installed in the casing 1, wherein the casing 1 is fixedly and vertically installed in the formation. The pressure reduction control device includes an outer cylinder 2 and an inner cylinder 3. The outer cylinder 2 is rotatably installed in the casing 1. The inner cylinder 3 is fixedly installed on the outer cylinder 2 by three connecting rods 10. The connecting rods 10 are support rods, one end of which is fixedly installed on the inner cylinder 3, and the other end is fixedly installed on the outer cylinder 2. Drill pipes 13 are threaded to both ends of the inner cylinder 3. The internal cavity of the inner cylinder 3 is an internal channel. An external channel 4 is formed between the inner wall of the outer cylinder 2 and the outer wall of the inner cylinder 3. The top of the outer cylinder 2 extends toward the inner cylinder 3 and forms a drain port 5 with the outer wall of the inner cylinder 3. The drain port 5 allows the drilling fluid in the external channel 4 to be discharged upward. Most of the drilling fluid is discharged along the external channel 4 through the drain port 5.

[0021] In this embodiment, several drainage holes 6 are also provided on the side wall of the inner cylinder 3. Each drainage hole 6 is a through hole that is thicker at both ends and thinner in the middle. One end of the drainage hole 6 is connected to the internal channel, and the other end of the drainage hole 6 is connected to a jet pipe 7. The number of jet pipes 7 is the same as the number of drainage holes 6. The jet pipes 7 are vertically curved pipes, distributed vertically upward and located below the drainage port 5. The outlet end of the jet pipe 7 is directly opposite the drainage port 5, guiding the drilling fluid to be sprayed out along the drainage port 5. When this embodiment is working, the drilling fluid enters the drill bit 14 along the internal channel. The drilling fluid cools the highly rotating drill bit 14 and flushes the cuttings into the drilling fluid. As the downhole pressure continues to increase, the drilling fluid carrying the cuttings is ejected along the external channel 4 through the drainage port 5, reducing the downhole pressure. Some of the drilling fluid is directly ejected along the jet pipe 7 through the drainage port 5, forming a jet stream, which plays a guiding role for the drilling fluid in the external channel 4.

[0022] In this embodiment, the inner cylinder 3 is provided with several vent holes 8 for air intake. These vent holes 8 are evenly and vertically distributed on the side wall of the inner cylinder 3. The bottom end of each vent hole 8 is connected to the middle section of the drainage hole 6, and the top end of each vent hole 8 is connected to an air pipe 9. The air inlet end of the air pipe 9 is connected to the atmosphere. The air pipe 9 is fixedly installed on the drill rod 13 by a cable tie and rotates with the drill rod 13. This allows external air to enter the drainage hole 6 along the air pipe 9, increasing the gas content in the drilling fluid ejected from the injection pipe 7. The air bubbles move upwards, pushing the drilling fluid above the drainage port 5 upwards, thereby causing the drilling fluid below the drainage port 5 to flow upwards and accelerating the speed at which the drilling fluid is discharged from the drainage port 5. In other words, the speed at which the drilling fluid is discharged from the drainage port 5 is increased through air lifting.

[0023] In this embodiment, as Figure 1 As shown, along the axial direction of the inner cylinder 3, the inner cylinder 3 is divided into an upper section and a lower section. The drilling fluid flows from the upper section to the lower section. The inner diameter of the upper section is larger than that of the lower section, and the diameter change point is a conical surface. The angle between the conical surface and the central axis of the inner cylinder 3 is 60 degrees. In other embodiments of this scheme, the angle between the conical surface and the central axis of the inner cylinder 3 is greater than 10 degrees and less than 75 degrees. The diameter of the inner cylinder 3 gradually decreases, and the flow velocity of the drilling fluid gradually increases. The drainage hole 6 is located on the conical surface, which will increase the initial liquid velocity of the drilling fluid entering the jet pipe 7, and thus increase the velocity of the jet stream ejected from the outlet of the jet pipe 7.

[0024] In this embodiment, an annular baffle 11 is fixedly installed at the top of the outer cylinder 2. A funnel-shaped channel is formed between the inner wall of the annular baffle 11 and the outer wall of the inner cylinder 3. The outlet 5 is located at the outlet end of the funnel-shaped channel. A guide ring 12 is installed at the top of the annular baffle 11. The guide ring 12 and the annular baffle 11 are integrally formed. A guide channel with a gradually increasing inner diameter is formed between the guide ring 12 and the outer wall of the inner cylinder 3. The outlet 5 is located at the inlet end of the guide channel. The drilling fluid is discharged through the outlet 5 along the outer channel 4. Along the upward flow direction of the drilling fluid, the inner diameter of the outer channel gradually decreases from the outlet to the guide channel and then gradually increases again, which increases the velocity of the drilling fluid flowing out of the guide channel, forming a secondary jet effect. This guides the drilling fluid in the outer channel to be discharged from the outlet, which facilitates rapid reduction of downhole pressure and maintenance of downhole pressure balance.

Claims

1. A pressure reduction control device for oil and gas field drilling equipment, characterized in that: It includes an outer cylinder (2) and an inner cylinder (3). The inner cylinder (3) is fixedly installed on the outer cylinder (2) by a connecting rod (10). An external channel (4) is formed between the inner wall of the outer cylinder (2) and the outer wall of the inner cylinder (3). The top of the outer cylinder (2) extends toward the inner cylinder (3) and forms a drainage port (5) with the outer wall of the inner cylinder (3). The drainage port (5) allows the drilling fluid in the external channel (4) to be discharged upward. A drainage hole (6) is also provided on the side wall of the inner cylinder (3). A jet pipe (7) is connected to the drainage hole (6). The jet pipe (7) is vertically distributed upward and located below the drainage port (5). A vent hole (8) for air intake is provided on the inner cylinder (3), and the vent hole (8) and the drainage hole (6) are connected. The drainage hole (6) is a through hole that is thick at both ends and thin in the middle. The vent hole (8) is connected to the middle section of the drainage hole (6). The vent hole (8) is connected to an air pipe (9). The air inlet end of the air pipe (9) is connected to the atmosphere.

2. The pressure reduction control device for oil and gas field drilling equipment according to claim 1, characterized in that: Along the axial direction of the inner cylinder (3), the inner diameter of the upper section of the inner cylinder (3) is larger than that of the lower section, and the diameter change point is a conical surface, with the drainage hole (6) located on the conical surface.

3. The pressure reduction control device for oil and gas field drilling equipment according to claim 2, characterized in that: The angle between the conical surface and the central axis of the inner cylinder (3) is greater than 10 degrees and less than 75 degrees.

4. The pressure reduction control device for oil and gas field drilling equipment according to claim 1, characterized in that: The spray pipe (7) is a right-angle bend, and the outlet end of the spray pipe (7) is directly opposite the drain port (5).

5. The pressure reduction control device for oil and gas field drilling equipment according to claim 1, characterized in that: The top of the outer cylinder (2) is provided with an annular baffle (11), and a funnel-shaped channel is formed between the inner wall of the annular baffle (11) and the outer wall of the inner cylinder (3). The drain port (5) is located at the outlet end of the funnel-shaped channel.

6. The pressure reduction control device for oil and gas field drilling equipment according to claim 5, characterized in that: A flow guide ring (12) is provided on the annular baffle (11), and a flow guide channel with a gradually increasing inner diameter is formed between the flow guide ring (12) and the inner cylinder (3). The inlet (5) is located at the inlet end of the flow guide channel.

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