A downhole disturbing flow and sand carrying device

Abstract

The present invention provides a downhole flow-disturbing sand-carrying device, comprising: a body for connection to an oil production pump, the body having a first channel for fluid circulation therein; and a second channel extending radially out of the body, the second channel having a liquid inlet remote from the body and a liquid outlet connected to the first channel. The size of the second channel gradually decreases as it approaches the body, such that the flow rate of the fluid flowing from the liquid inlet to the liquid outlet gradually increases. The downhole flow-disturbing sand-carrying device of the present invention can effectively increase the flow rate and sand-carrying capacity of downhole fluids, thereby preventing the occurrence of sand settling at the bottom of the oil well.

Description

Technical Field

[0001] The invention relates to the field of oil and gas exploitation, and in particular to an underground disturbing flow and sand carrying device. Background Art

[0002] Unconsolidated sandstone reservoirs are often encountered during oil production. These reservoirs contain large amounts of formation sand and gravel during oil production. Therefore, to increase well productivity and reduce maintenance, jet pumps or progressive cavity pumps are often used to carry sand through unconsolidated sandstone reservoirs.

[0003] In actual production, the fluid velocity in the reservoir completion section of an oil well gradually decreases from the top. Furthermore, because the inner area of ​​the downhole casing is several times that of the tubing (or pump liner), the fluid velocity in all or part of the reservoir completion section is low, often below the critical sand-carrying velocity. This results in low pump sand-carrying efficiency, leading to sand settling at the bottom of the well. When this occurs, the completion section can be buried in the sand, impacting normal production. Summary of the Invention

[0004] In response to the technical problems mentioned above, the present invention aims to propose a downhole turbulent flow and sand carrying device. The downhole turbulent flow and sand carrying device of the present invention can effectively increase the flow rate and sand carrying capacity of the downhole fluid, and avoid the occurrence of sand settling at the bottom of the oil well.

[0005] According to the present invention, a downhole flow-disturbing sand-carrying device is provided, comprising: a body for connection to an oil production pump, the body having a first channel therein for fluid circulation; and a second channel extending radially out of the body, the second channel having a liquid inlet remote from the body and a liquid outlet communicating with the first channel.

[0006] The size of the second channel gradually decreases in a direction approaching the body, so that the flow rate of the fluid flowing from the liquid inlet to the liquid outlet gradually increases.

[0007] In a preferred embodiment, an upper cover and a lower cover extending radially along the body are provided at one end of the body away from the oil production pump, and the second channel is provided between the upper cover and the lower cover.

[0008] In a preferred embodiment, a plurality of separators evenly distributed along the circumference are provided on the lower cover body, so that the second channel is divided into a plurality of flow channels distributed along the circumference of the lower cover body, and the size of the separators gradually increases in the direction approaching the main body.

[0009] In a preferred embodiment, the upper cover and the lower cover have a first curved surface that curves toward the oil production pump, and the side wall of the separator is configured as a second curved surface, the ends of which converge at the drain port.

[0010] In a preferred embodiment, a conical guide plate is further provided on the side wall of the oil production pump, and the free end of the guide plate is connected to the upper cover.

[0011] In a preferred embodiment, the invention further comprises a sealing member provided at one end of the second channel close to the liquid inlet.

[0012] In a preferred embodiment, the side wall of the sealing member close to the body is configured as a conical surface.

[0013] In a preferred embodiment, a filter layer is further provided on the liquid discharge port.

[0014] In a preferred embodiment, the upper cover, the lower cover and the guide plate are made of ceramic material, and the guide plate is detachably connected to the body.

[0015] In a preferred embodiment, a shock-absorbing ring is further provided between the main body and the upper cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be described below with reference to the accompanying drawings.

[0017] Figure 1 A schematic diagram of a downhole flow disturbing sand carrying device according to the present invention is shown.

[0018] Figure 2 for Figure 1 The schematic cross-sectional view of the downhole disturbing flow and sand carrying device along the AA' direction is shown.

[0019] Figure 3 for Figure 1 The schematic cross-sectional view of the downhole disturbing flow and sand carrying device along the BB' direction is shown.

[0020] In this application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn to scale. DETAILED DESCRIPTION

[0021] The present invention will be described below with reference to the accompanying drawings.

[0022] Figure 1 FIG. 1 shows a downhole flow disturbing sand carrying device 100 according to an embodiment of the present invention. Figure 1As shown, the downhole flow-disturbing sand-carrying device 100 includes a body 10 for connection to an oil production pump 11. The body 10 is tubular and defines a first passage 20 for fluid circulation. The first passage 20 is connected to the suction port of the oil production pump 11. The fluid in the first passage 20 is thus transported to the surface wellhead via the oil production pump 11.

[0023] The body 10 is also provided with a second channel 30 for fluid circulation, communicating with the first channel 20. Specifically, the body 10 is provided with an upper cover 42 and a lower cover 44 extending radially along the body 10. A gap 43 is formed between the upper cover 42 and the lower cover 44, and the second channel 30 is disposed within the gap 43.

[0024] like Figure 1 As shown, the end of the second channel 30 away from the body 10 is formed as a liquid inlet 36, and the end close to the body 10 is formed as a liquid outlet 38. The liquid outlet 38 extends into the first channel 20, thereby ensuring the communication between the first channel 20 and the second channel 30.

[0025] In the present invention, the size of the second channel 30 gradually decreases as it approaches the body 10. It is easy to understand that as the downhole fluid flows from the fluid inlet 36 to the fluid outlet 38, the fluid flow rate gradually increases as the size of the second channel 30 decreases. Thus, by increasing the downhole fluid flow rate, the flow rate reaches the critical sand-carrying velocity.

[0026] Since the sand content of downhole fluid varies from one oil well to another, the critical sand-carrying velocity varies from one oil well to another. By adjusting the dimensional difference between the two ends of the second channel 30, the difference in velocity between the outflow velocity of the downhole fluid at the inlet and outlet 38 and the inflow velocity at the inlet 36 can be adjusted. By flexibly adjusting the dimensional difference between the two ends of the second channel 30 according to different sand content and inflow velocity, the downhole turbulent flow sand-carrying device 100 can be adapted to oil wells with different operating conditions.

[0027] According to Bernoulli's theorem, as the flow rate of the fluid flowing into the second channel 30 increases, its pressure decreases, thereby forming a pressure difference across the two ends of the second channel 30, that is, the pressure at the discharge port 38 is lower than the pressure at the inlet port 36. It is easy to understand that this pressure difference not only helps to further increase the flow rate of the fluid, but also makes it easier for the downhole fluid carrying sand and gravel to flow from the second channel 30 into the first channel 20.

[0028] In addition, as the velocity of the downhole fluid increases, its Reynolds number Re also increases, thereby changing the flow state of the downhole fluid in the second channel 30 from laminar to turbulent. When the downhole fluid is in a turbulent state, the sand and gravel contained in the fluid can be fully stirred, thereby not only improving the sand-carrying capacity of the downhole fluid, but also preventing sand and gravel from accumulating and clogging the oil production pump 11, the first channel 20, and the second channel 30.

[0029] In a preferred embodiment, the upper cover 42 and the lower cover 44 are configured as a first curved surface 41 that curves toward the oil pump 11, forming the second channel 30 into a curved channel. Compared to traditional straight channels, this irregular curved channel helps further increase the Reynolds number of the downhole fluid.

[0030] like Figure 1 As shown, in a preferred embodiment, a guide plate 25 is further provided on the side wall of the oil production pump 11. The free end 26 of the guide plate 25 is connected to the liquid inlet 36, so that the liquid inlet 36 is located on the side of the free end 26 away from the body 10. The guide plate 25 is configured to be conical, so that the guide plate 25 can collect and guide the downhole fluid flowing into the liquid inlet 36, thereby improving the efficiency of the liquid inlet 36 in collecting the downhole fluid.

[0031] Meanwhile, a filter layer 37 is provided at the liquid inlet 36. The filter layer 37 can filter underground solid impurities exceeding the particle size outside the second channel 30 to prevent these solid impurities from clogging underground channels such as the second channel 30 and the first channel 20.

[0032] In addition, if Figure 1 As shown, a seal 50 is further provided on the side of the filter layer 37 away from the body 10. The seal 50 is preferably configured as a deformable elastic member, and its dimensions are slightly larger than those of the well wall. Thus, when the downhole flow-disturbing sand-carrying device 100 is located downhole, it can deform to a certain extent and abut against the well wall, thereby preventing fluid above the downhole flow-disturbing sand-carrying device 100 from bypassing the second channel 30 and flowing below the downhole flow-disturbing sand-carrying device 100.

[0033] In a preferred embodiment, the sidewall 55 of the sealing member 50 close to the body 10 is configured as a conical surface. This allows the sealing member 50 to also collect and guide the downhole fluid flowing in from the liquid inlet 36, further improving the efficiency of the liquid inlet 36 in collecting downhole fluid.

[0034] In a preferred embodiment, the deflector 25 is detachably connected to the body 10. Specifically, the deflector 25 and the body 10 are connected via shear pins 16. In this way, under extreme conditions, when the downhole flow-disturbing sand-carrying device 100 fails to carry sand effectively, causing formation sand to settle and become stuck, personnel can lift the tubing string to shear the shear pins 16, thereby separating the oil production pump 11 from the downhole flow-disturbing sand-carrying device 100.

[0035] At the same time, the upper cover 42, lower cover 44, and guide plate 25 are preferably made of a ceramic material that is easily ground by tools such as grinding shoes. Therefore, after the oil pump 11 is separated from the downhole flow-disturbing sand-carrying device 100, the oil pump 11 can be lifted and a grinding shoe or other tool can be lowered into the well to drill and grind the upper cover 42, lower cover 44, and guide plate 25 that remain unlifted until the drilled and ground debris can be carried out of the wellhead by the workover fluid. This arrangement effectively prevents fish dropping accidents downhole.

[0036] In addition, if Figure 1 As shown, a shock-absorbing ring 19 is further provided at the connection between the main body 10 and the upper cover 42. The upper cover 42 and the main body 10 are connected via the shock-absorbing ring 19. The shock-absorbing ring 19 is made of a material with excellent elasticity and can reduce relative vibration between the oil production pump 11 and the main body 10. This prevents the ceramic material from cracking and fatigue failure during vibration, thereby improving the stability and service life of the downhole turbulent flow sand carrying device 100.

[0037] Figure 2 for Figure 1 The cross-sectional diagram of the underground disturbing flow and sand carrying device along the A-A' direction is shown in FIG. Figure 2 As shown, the filter layer 37 is provided as a grid filter. The filtering accuracy can be adjusted according to different production practices to increase the scope of use of the filter layer 37.

[0038] Figure 3 for Figure 1 The cross-sectional diagram of the underground disturbing flow and sand carrying device along the BB' direction is shown in FIG. Figure 3 As shown, a plurality of separators 60 are provided on the lower cover 44. The separators 60 are evenly arranged along the circumference of the lower cover 44, so that the second channel 30 is divided into a plurality of independent flow channels 65 evenly distributed along the circumference of the lower cover 44. The size of the separators 60 is configured to gradually increase in the direction approaching the body 10, ensuring that the size of the flow channels 65 gradually decreases in this direction (i.e., the size of the second channel 30 gradually decreases in this direction).

[0039] In a preferred embodiment, the sidewalls of the separator 60 are also configured as irregular second curved surfaces 61, the ends of which converge at the drainage port 38. Thus, by utilizing the separator 60, the upper cover 42, and the lower cover 44, the sidewalls of the flow channel 65 (i.e., the second channel 30) can be simultaneously configured as irregular curved surfaces. This configuration further increases the Reynolds number of the downhole fluid flowing through the second channel 30, improving the sand-carrying effect of the downhole fluid.

[0040] The working process of the downhole flow disturbing sand carrying device 100 according to the present invention is briefly described below.

[0041] The downhole flow-disturbing sand-carrying device 100 of the present invention is designed to be connected to the oil production pump 11 and lowered into the well completion section along with the downhole tubing. During oil well production, the sand-laden fluid produced from the well flows under the influence of gravity through the guide plate 25 into the second channel 30. As the fluid flows through the second channel 30, its flow rate gradually increases to a critical sand-carrying velocity.

[0042] At the same time, as the fluid flows through the second channel 30, its Reynolds number increases, and the fluid enters a turbulent state. At this point, the turbulent fluid can fully agitate the sand and gravel it carries, thereby further improving the fluid's sand-carrying capacity and preventing sand and gravel from clogging the various pipes downhole.

[0043] When the fluid reaches the drain port 38 , it enters the first channel 20 and is transported to the surface by the oil production pump 11 .

[0044] If the downhole turbulent flow sand carrying device 100 fails to carry sand effectively, the remaining sand can be deposited beneath the device via 38. If formation sand deposition causes a sand jam, the operator can lift the tubing string to shear the shear pins 16, separating the body 10 from the downhole turbulent flow sand carrying device 100. The body 10 is then lifted and a grinding shoe or other tool is lowered into the well to drill and grind the remaining portion of the downhole turbulent flow sand carrying device 100. The resulting debris can be carried out of the wellhead by the workover fluid.

[0045] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A downhole disturbing flow and sand carrying device, comprising: A body (10) for connection to an oil production pump (11), the body having a first channel (20) for fluid circulation, and a second channel (30) extending radially out of the body, the second channel having a liquid inlet (36) away from the body and a liquid outlet (38) communicating with the first channel, The size of the second channel gradually decreases as it approaches the body, so that the flow rate of the fluid flowing from the liquid inlet to the liquid outlet gradually increases. An upper cover (42) and a lower cover (44) extending radially along the body are provided at one end of the body away from the oil production pump, and the second channel is provided between the upper cover and the lower cover. A plurality of separators (60) uniformly distributed along the circumference are provided on the lower cover, so that the second channel is divided into a plurality of flow channels (65) distributed along the circumference of the lower cover. The size of the separator gradually increases along a direction approaching the main body.

2. The underground disturbing flow and sand carrying device according to claim 1, characterized in that: The upper cover and the lower cover have a first curved surface (41) curved toward the oil pump. The side wall of the separator is configured as a second curved surface (61), and the ends of the second curved surface converge at the drain port.

3. The underground disturbing flow and sand carrying device according to claim 1 or 2, characterized in that: A conical guide plate (25) is also provided on the side wall of the main body, and a free end (26) of the guide plate is connected to the upper cover.

4. The underground disturbing flow and sand carrying device according to claim 1 or 2, characterized in that: The invention also includes a sealing member (50) arranged at one end of the second channel close to the liquid inlet.

5. The underground disturbing flow and sand carrying device according to claim 4, characterized in that: The side wall (55) of the sealing member close to the body is configured as a conical surface.

6. The underground disturbing flow and sand carrying device according to claim 1 or 2, characterized in that: A filter layer (37) is also provided on the liquid inlet.

7. The underground disturbing flow and sand carrying device according to claim 3, characterized in that: The upper cover, the lower cover and the guide plate are made of ceramic material, and the guide plate is connected to the main body in a detachable manner.

8. The underground disturbing flow and sand carrying device according to claim 1 or 2, characterized in that: A shock-absorbing ring (19) is also provided between the main body and the upper cover.

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