Bottom bottom supercharger

Abstract

The invention relates to a downhole supercharger. The downhole supercharger comprises a barrel, a pressure cylinder, a pilot valve and a control valve assembly. A first chamber and a second chamber are arranged in the cylinder body, and the pressure in the first chamber is larger than that in the second chamber. A piston assembly, a first pushing cavity and a second pushing cavity are arranged in the pressure cylinder. The pilot valve is for fluid communication with the first chamber and the second chamber. The control valve assembly is for fluid communication with the pilot valve. The pilot valve is configured to enable the first pushing cavity to be in fluid communication with the first cavity through the control valve assembly when the piston assembly enables the volume of the first pushing cavity to be minimum, and enable the second pushing cavity to be in fluid communication with the second cavity through the control valve assembly, so that the downhole supercharger starts to conduct downward supercharging. The pilot valve is further configured to enable the first pushing cavity to be in fluid communication with the second cavity through the control valve assembly when the piston assembly enables the volume of the first pushing cavity to be maximum, and enable the second pushing cavity to be in fluid communication with the first cavity through the control valve assembly, so that the well bottom pressurizer starts ascending pressurization.

Description

Technical Field

[0001] This invention relates to the field of bottom hole boosting technology, and more specifically to a bottom hole booster. Background Technology

[0002] Bottom-hole pressurized ultra-high pressure jet-assisted drilling technology utilizes a specially designed bottom-hole pressurization device in conjunction with a specialized drill bit to achieve ultra-high pressure jet-assisted drilling, effectively increasing drilling speed. This technology can fully utilize existing surface equipment and conventional circulation systems, eliminating the need to transport high-pressure fluid from the surface to the bottom of the well. Due to the limitations of wellbore size in oil drilling, both domestically and internationally, hydraulically driven large-diameter piston pairs are commonly used to drive the reciprocating motion of plungers to achieve bottom-hole pressurization. To achieve the reciprocating motion of the piston, a pressure difference must be established between the upper and lower chambers of the piston cylinder; the greater the pressure difference, the higher the output pressure of the plunger pressurization cylinder.

[0003] In existing technologies, some booster devices can only achieve boosting during the unidirectional movement of the piston, and cannot achieve continuous boosting during the reciprocating motion of the piston. For example, the invention patent with publication number CN1908452A discloses a fluid booster that uses an internal throttling element to control the pressure drop (the pressure difference between the low-pressure chamber and the high-pressure chamber of the piston cylinder during boosting) and uses a jet-attached reversing element combined with a mechanical valve to achieve the reciprocating motion of the piston, and achieves unidirectional boosting only during the downward movement of the piston. Summary of the Invention

[0004] In view of the above-mentioned problems existing in the prior art, the present invention provides a bottom-hole booster that can realize the reciprocating motion of the piston through a logic valve and achieve continuous pressurization during the reciprocating motion of the piston.

[0005] The technical solution adopted by this invention to solve its technical problem is: to provide a bottom-hole booster, comprising,

[0006] A cylinder for connecting a drill bit, wherein the cylinder has a first chamber for inputting drilling fluid and a second chamber for outputting drilling fluid to the drill bit, wherein the pressure in the first chamber is greater than the pressure in the second chamber;

[0007] A booster cylinder is used to pressurize the drilling fluid in the first chamber and deliver it to the drill bit. The booster cylinder is provided with a piston assembly for pressurization, and a first push chamber and a second push chamber separated by the piston assembly.

[0008] A pilot valve, disposed within the cylinder, is used for fluid communication between the first chamber and the second chamber; and

[0009] A control valve assembly, disposed within the cylinder, is used for fluid communication with the pilot valve.

[0010] The pilot valve is configured to connect the first push chamber to the first chamber via the control valve assembly when the volume of the first push chamber is minimized by the piston assembly, and to connect the second push chamber to the second chamber via the control valve assembly, thereby initiating the downhole booster to descend and increase pressure.

[0011] Furthermore, the system is configured to allow fluid communication between the first push chamber and the second chamber via the control valve assembly when the piston assembly maximizes the volume of the first push chamber, and to allow fluid communication between the second push chamber and the first chamber via the control valve assembly, thereby enabling the bottom-hole booster to begin upward pressurization.

[0012] Furthermore, the control valve assembly includes a valve body that, together with the booster cylinder, separates the first chamber and the second chamber, and four control valves mounted on the valve body.

[0013] The four control valves are configured to allow the first push chamber to be fluidly connected to the first chamber when the volume of the first push chamber is at its minimum, and to allow the first push chamber to be fluidly connected to the second chamber when the volume of the first push chamber is at its maximum.

[0014] Furthermore, each of the control valves includes a valve sleeve mounted on the valve body, a valve core disposed within the valve sleeve, and a valve cover connected to the valve sleeve. The valve sleeve has an inlet and an outlet on its bottom and side wall, respectively. The valve cover has a control port for fluid communication with the valve core. The valve core contains an elastic element that abuts against the valve cover.

[0015] Wherein, the sum of the minimum elastic force of the elastic element and the force exerted by the drilling fluid in the second chamber on the valve core through the control port is less than the force exerted by the drilling fluid in the first chamber on the valve core through the inlet, so that the inlet and outlet are connected.

[0016] Furthermore, the four control valves are a first control valve, a second control valve, a third control valve, and a fourth control valve. The inlet of the first control valve and the outlet of the second control valve are fluidly connected to the first push chamber. The inlets of the second control valve and the third control valve are fluidly connected to the first chamber. The outlet of the third control valve and the inlet of the fourth control valve are fluidly connected to the second push chamber. The outlet of the fourth control valve and the outlet of the first control valve are fluidly connected to the second chamber.

[0017] Furthermore, the pilot valve is configured to allow fluid communication between the control ports of the first control valve and the third control valve and the control ports of the second control valve and the fourth control valve in the first chamber during downward pressurization.

[0018] During the upward pressurization, the control ports of the first control valve and the third control valve are fluidly connected to the second chamber, and the control ports of the second control valve and the fourth control valve are fluidly connected to the first chamber.

[0019] Furthermore, a connecting rod extending axially into the first actuation chamber is connected to the valve stem of the pilot valve, and a control element is installed at one end of the connecting rod located in the first actuation chamber.

[0020] The control element is configured to move the connecting rod axially via the piston assembly when the volume of the first push chamber is at its minimum or maximum, so as to adjust the pilot valve.

[0021] Furthermore, the piston assembly includes a piston rod extending axially within the booster cylinder, a push piston mounted on the piston rod and used to separate the first push chamber and the second push chamber, and a first piston and a second piston respectively mounted at both ends of the piston rod.

[0022] The control element is configured to be pushed axially upward by the push piston or axially downward by the first piston, so that the connecting rod can move axially.

[0023] Furthermore, the booster cylinder is also provided with a first booster chamber separated from the first push chamber by the first piston, and a second booster chamber separated from the second push chamber by the second piston. The first booster chamber and the second booster chamber are respectively connected to the first chamber through a first inlet valve and a second outlet valve installed on the booster cylinder. The first booster chamber and the second booster chamber are respectively connected to the drill bit through a first outlet valve and a second outlet valve installed on the booster cylinder.

[0024] Furthermore, both the first inlet valve and the first outlet valve are one-way valves, so that the drilling fluid in the first chamber can enter the first pressurization chamber through the first inlet valve as the volume of the first push chamber increases.

[0025] Furthermore, the cross-sectional area of ​​the push piston is larger than that of the first piston, so that the drilling fluid in the first pressurization chamber can be pressurized during the process of the volume of the first push chamber decreasing and flow to the drill bit through the first outlet valve.

[0026] Furthermore, both the second inlet valve and the second outlet valve are one-way valves, so that the drilling fluid in the first chamber can enter the second pressurization chamber through the first inlet valve as the volume of the first push chamber decreases.

[0027] Furthermore, the cross-sectional area of ​​the push piston is larger than that of the second piston, so that the drilling fluid in the second pressurization chamber can be pressurized during the increase of the volume of the first push chamber and flow to the drill bit through the second outlet valve.

[0028] The beneficial effects of this invention are as follows: This invention provides a bottom-hole booster, comprising a cylinder for connecting to a drill bit, a booster cylinder for pressurizing drilling fluid in a first chamber and delivering it to the drill bit, a pilot valve disposed within the cylinder, and a control valve assembly disposed within the cylinder. The cylinder contains a first chamber for inputting drilling fluid and a second chamber for outputting drilling fluid to the drill bit, wherein the pressure in the first chamber is greater than the pressure in the second chamber. The booster cylinder contains a piston assembly for pressurization, and a first push chamber and a second push chamber separated by the piston assembly. The pilot valve is used to fluidly connect the first chamber and the second chamber. The control valve assembly is used to fluidly connect the pilot valve. Specifically, the pilot valve is configured to, when the piston assembly minimizes the volume of the first push chamber, allow the first push chamber to fluidly connect to the first chamber via the control valve assembly, and also allow the second push chamber to fluidly connect to the second chamber via the control valve assembly, thereby initiating downward pressurization of the bottom-hole booster. Furthermore, the pilot valve is configured to connect the first push chamber to the second chamber via the control valve assembly when the piston assembly maximizes the volume of the first push chamber, and to connect the second push chamber to the first chamber via the control valve assembly, thereby initiating upward pressurization of the bottom hole booster. This allows the reciprocating motion of the piston to be achieved via a logic valve, and continuous pressurization to be achieved during the piston's reciprocating motion.

[0029] With the equipment in the conventional circulation system remaining largely unchanged, this downhole booster can continuously pressurize the drilling fluid to ultra-high pressure to assist the drill bit in breaking rock, achieving ultra-high pressure hydraulic-mechanical combined rock breaking and significantly improving rock breaking efficiency. Furthermore, this downhole booster eliminates the need to transport high-pressure fluid from the surface to the well bottom, making full use of existing surface equipment, thus reducing investment and facilitating wider application. Attached Figure Description

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Figure 1 The image shown is a cross-sectional view of a bottom-hole booster.

[0032] Figure 2 As shown Figure 1 The image shows a partial enlarged view of the pilot valve installation location on the bottom-of-well booster.

[0033] Figure 3 As shown Figure 1 The image shows a partial enlarged view of the control valve installation location on the bottom-of-well booster.

[0034] Figure 4 As shown Figure 1 The diagram shows a simplified representation of the drilling fluid flow direction during the downhole pressurization process in the bottom-hole booster (the dashed arrows in the diagram indicate the flow direction of the drilling fluid).

[0035] Figure 5 As shown Figure 1 The diagram shows a simplified representation of the drilling fluid flow direction during the upward pressurization process in the bottom-hole booster (the arrows with dashed lines in the diagram indicate the flow direction of the drilling fluid).

[0036] In the figure, the following labels are used: 100, bottom-of-well booster; 10, cylinder; 11, upper connector; 111, first guide element; 12, lower connector; 121, second guide element; 13, first chamber; 14, second chamber; 141, throttling nozzle;

[0037] 20. Pressure booster cylinder; 21. Main body; 211. First push chamber; 212. Second push chamber; 22. First pressure boosting section; 221. First pressure boosting chamber; 222. First inlet valve; 223. First outlet valve; 23. Second pressure boosting section; 231. Second pressure boosting chamber; 232. Second inlet valve; 233. Second outlet valve; 240. Piston assembly; 24. Piston rod; 241. First piston; 242. Second piston; 243. Pushing piston;

[0038] 30. Pilot valve; 31. Valve stem; 32. Connecting rod; 33. Control component;

[0039] 40. Control valve assembly; 41. Valve body; 42. Control valve; 421. Valve core; 422. Valve sleeve; 423. Valve cover; 424. Inlet; 425. Outlet; 426. Control port; 427. Elastic element; 42a. First control valve; 42b. Second control valve; 42c. Third control valve; 42d. Fourth control valve. Detailed Implementation

[0040] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic structure of the invention, and therefore only shows the components relevant to the invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] refer to Figure 1 As shown, the bottom-hole booster 100 provided by the present invention includes a hollow cylinder 10 with openings at both ends, an upper connector 11 disposed at the upper end of the cylinder 10 for connecting to the drill pipe, and a lower connector 12 disposed at the lower end of the cylinder 10 for connecting to a drill bit with a high-pressure nozzle. In the axially downward direction, a control valve assembly 40 and a booster cylinder 20 for pressurizing drilling fluid are sequentially disposed inside the cylinder 10. The control valve assembly 40 and the booster cylinder 20 divide the internal space of the cylinder 10 into a first chamber 13 communicating with the upper connector 11 and a second chamber 14 communicating with the lower connector 12. The fluid pressure in the first chamber 13 is greater than the fluid pressure in the second chamber 14. A pilot valve 30, which cooperates with the control valve assembly 40, is also disposed on the booster cylinder 20 to adjust the pressurization process of the booster cylinder 20.

[0042] In some preferred embodiments, a throttling nozzle 141 is provided between the first chamber 13 and the second chamber 14 to adjust the fluid pressure difference between the two chambers. By selecting throttling nozzles 141 with different throttling orifice diameters, the fluid pressure difference between the first chamber 13 and the second chamber 14 can be controlled, thereby making the bottomhole booster 100 suitable for different well depths.

[0043] It should be noted that the bottom-hole booster 100 is also provided with several flow channels (not shown in the figure) for the drilling fluid to flow between the first chamber 13, the second chamber 14, the control valve assembly 40, the booster cylinder 20, and the pilot valve 30. Those skilled in the art can adaptably arrange several of these flow channels within the bottom-hole booster 100. These flow channels can be constructed by pipes arranged within the bottom-hole booster 100, or by providing through channels in structural components such as the cylinder body and barrel 10 of the booster cylinder 20. This application will not elaborate further on this.

[0044] In some embodiments, a first guide member 111 is provided between the upper connector 11 and the cylinder 10 for guiding drilling fluid entering the bottom-hole booster 100 from the upper connector 11. In this embodiment, the first guide member 111 is configured to guide all the drilling fluid passing through the upper connector 11 into the first chamber 13 through its internal flow channels. In other embodiments not shown, the first guide member 111 is configured to guide a portion of the drilling fluid passing through the upper connector 11 to the pilot valve 30 and the booster cylinder 20 through its internal flow channels, such that the first chamber 13, the pilot valve 30, and the booster cylinder 20 are connected in parallel.

[0045] In this embodiment, the pilot valve 30 and the booster cylinder 20 are connected in parallel to the first chamber 13, so that the drilling fluid passing through the upper connector 11 enters the first chamber 13 under the guidance of the first guide 111 and then flows to the pilot valve 30 and the booster cylinder 20 respectively.

[0046] In some embodiments, a second guide member 121 is further provided between the cylinder 10 and the lower connector 12 for guiding the drilling fluid flowing out of the second chamber 14 and the booster cylinder 20. In this embodiment, the second guide member 121 is configured to guide the drilling fluid in the second chamber 14 to the ordinary nozzle of the drill bit for cleaning the bottom of the well. The second guide member 121 is also configured to guide the drilling fluid pressurized by the booster cylinder 20 to the high-pressure nozzle of the drill bit for assisting drilling.

[0047] Combination Figure 1As shown, in some embodiments, the booster cylinder 20 includes a main body 21 and a first booster portion 22 and a second booster portion 23 respectively disposed at both ends of the main body 21. The inner diameter of the main body 21 is larger than the inner diameter of the first booster portion 22 and the second booster portion 23. A piston assembly 240 is also disposed within the booster cylinder 20, the piston assembly 240 including a piston rod 24 extending axially. A first piston 241 located within the first booster portion 22 and a second piston 242 located within the second booster portion 23 are respectively disposed at both ends of the piston rod 24, while a pushing piston 243 located within the main body 21 is disposed at the middle of the piston rod 24. Sealing rings are disposed on the circumferential sidewalls of the first piston 241, the pushing piston 243, and the second piston 242, so that the first piston 241, the pushing piston 243, and the second piston 242 are respectively pressurized against the inner walls of the first booster portion 22, the main body 21, and the second booster portion 23. The first piston 241, the pushing piston 243, and the second piston 242 sequentially divide the internal cavity of the booster cylinder 20 into a first booster chamber 221, a first pushing chamber 211, a second pushing chamber 212, and a second booster chamber 231 in a downward axial direction. The inner diameters of the first pushing chamber 211 and the second pushing chamber 212 are larger than the inner diameters of the first booster chamber 221 and the second booster chamber 231, and the cross-sectional dimension of the pushing piston 243 is larger than the cross-sectional dimension of the first piston 241 and the second piston 242, so as to create an area difference to achieve the purpose of boosting.

[0048] Combination Figure 4 and Figure 5 As shown, in some embodiments, the first actuation chamber 211 is fluidly connected to the first chamber 13 or the second chamber 14 via the pilot valve 30 and the control valve assembly 40, and the second actuation chamber 212 is also fluidly connected to the first chamber 13 or the second chamber 14 via the pilot valve 30 and the control valve assembly 40.

[0049] In some embodiments, when the bottom-hole booster 100 performs downward pressurization, the first push chamber 211 is fluidly connected to the first chamber 13 through the pilot valve 30 and the control valve assembly 40, while the second push chamber 212 is fluidly connected to the second chamber 14 through the pilot valve 30 and the control valve assembly 40. At this time, the fluid pressure in the first push chamber 211 is greater than the fluid pressure in the second push chamber 212. Therefore, the push piston 243 can drive the piston rod 24 to move axially downward under the pressure difference between the first push chamber 211 and the second push chamber 212.

[0050] When the bottom-hole booster 100 performs upward pressurization, the first push chamber 211 is fluidly connected to the second chamber 14 through the pilot valve 30 and the control valve assembly 40, while the second push chamber 212 is fluidly connected to the first chamber 13 through the pilot valve 30 and the control valve assembly 40. At this time, the fluid pressure in the first push chamber 211 is lower than the fluid pressure in the second push chamber 212. Therefore, the push piston 243 can drive the piston rod 24 to move axially upward under the pressure difference between the first push chamber 211 and the second push chamber 212.

[0051] refer to Figure 1 , Figure 4 and Figure 5 As shown, in some embodiments, the first pressurizing unit 22 is provided with a first inlet valve 222 for fluid communication between the first chamber 13 and the first pressurizing chamber 221, and a first outlet valve 223 for fluid communication between the first pressurizing chamber 221 and the high-pressure nozzle of the drill bit. Both the first inlet valve 222 and the first outlet valve 223 are one-way valves. The inlet end of the first inlet valve 222 is fluidly connected to the first chamber 13, and the outlet end of the first inlet valve 222 is fluidly connected to the first pressurizing chamber 221. The inlet end of the first outlet valve 223 is fluidly connected to the first pressurizing chamber 221, and the outlet end of the first outlet valve 223 is fluidly connected to the high-pressure nozzle of the drill bit.

[0052] In some embodiments, when the bottomhole booster 100 performs downward pressurization, the first piston 241 moves axially downward with the piston rod 24, allowing drilling fluid in the first chamber 13 to enter the first pressurization chamber 221 through the first inlet valve 222, while the drilling fluid in the high-pressure nozzle of the drill bit cannot flow back to the first pressurization chamber 221 through the first outlet valve 223. When the bottomhole booster 100 performs upward pressurization, the first piston 241 moves axially upward with the piston rod 24, allowing drilling fluid in the first pressurization chamber 221 to reach the high-pressure nozzle of the drill bit through the first outlet valve 223, but preventing it from flowing back to the first chamber 13 through the first inlet valve 222.

[0053] In some embodiments, the second pressurizing section 23 is provided with a second inlet valve 232 for fluid communication between the first chamber 13 and the second pressurizing chamber 231, and a second outlet valve 233 for fluid communication between the high-pressure nozzle of the drill bit in the second pressurizing chamber 231. Both the second inlet valve 232 and the second outlet valve 233 are one-way valves. The inlet end of the second inlet valve 232 is fluidly connected to the first chamber 13, and the outlet end of the second inlet valve 232 is fluidly connected to the second pressurizing chamber 231. The inlet end of the second outlet valve 233 is fluidly connected to the second pressurizing chamber 231, and the outlet end of the second outlet valve 233 is fluidly connected to the high-pressure nozzle of the drill bit.

[0054] In some embodiments, when the bottomhole booster 100 performs downward pressurization, the second piston 242 moves axially downward with the piston rod 24, allowing the drilling fluid in the second pressurization chamber 231 to reach the high-pressure nozzle of the drill bit through the second outlet valve 233, but preventing it from flowing back to the first chamber 13 through the second inlet valve 232. When the bottomhole booster 100 performs upward pressurization, the second piston 242 moves axially upward with the piston rod 24, allowing the drilling fluid in the first chamber 13 to enter the second pressurization chamber 231 through the second inlet valve 232, while the drilling fluid in the high-pressure nozzle of the drill bit cannot flow back to the second pressurization chamber 231 through the second outlet valve 233.

[0055] refer to Figure 1 and Figure 2 As shown, in some embodiments, the pilot valve 30 is a two-position four-way directional valve. The pilot valve 30 is mounted on the side wall of the first pressurizing part 22 of the pressurizing cylinder 20, and the valve stem 31 of the pilot valve 30 extends toward the stepped surface between the main body 21 and the first pressurizing part 22. The end of the valve stem 31 is provided with a connecting rod 32 that passes through the stepped surface in the axial direction, and the stepped surface is slidably sealed. One end of the connecting rod 32 located in the first push chamber 211 is connected to a control member 33, which is used to move the connecting rod 32 axially by moving the piston assembly 240. The control member 33 can move the valve stem 31 axially upward or downward via the connecting rod 32, thereby switching the energized state of the pilot valve 30.

[0056] In some embodiments, the connecting rod 32 is hinged to the valve stem 31 of the pilot valve 30 so that the connection state of the pilot valve 30 can be adjusted even when the axis of the connecting rod 32 is not collinear with the axis of the valve stem 31 of the pilot valve 30.

[0057] In some embodiments, the control element 33 is an annular sheet structure. An annular protrusion extending into the first pressurization chamber 221 is provided on the end face of the control element 33 near the first pressurization chamber 221. This annular protrusion, while allowing the piston rod 24 to pass through, also causes the first pressurization chamber 221 to narrow at the end near the first push chamber 211. This allows the valve stem 31 of the pilot valve 30 to be controlled by pushing the piston 243 or the first piston 241, thereby adjusting the connection state of the pilot valve 30 at the end of upward pressurization or downward pressurization.

[0058] In some embodiments, when the bottomhole booster 100 finishes its upward boosting and begins its downward boosting, the volume of the first push chamber 211 is at its minimum. At this time, the pilot valve 30 is in a first connected state, and the control element 33 is pressed against the inner end face of the main body 21 near the first boosting chamber 221 by the push piston 243. When the bottomhole booster 100 finishes its downward boosting and begins its upward boosting, the volume of the first push chamber 211 is at its maximum. At this time, the pilot valve 30 is in a second connected state, and the control element 33 is pushed away from the inner end face of the main body 21 near the first boosting chamber 221 by the first piston 241.

[0059] Combination Figure 1 and Figure 3 As shown, in some embodiments, the control valve assembly 40 includes a valve body 41 and four control valves 42 mounted on the valve body 41. Each control valve 42 includes a valve sleeve 422 mounted on the valve body 41, a valve core 421, a valve core 421 disposed within the valve sleeve 422, and a valve cover 423 for connecting the valve sleeve 422 and the valve body 41. The valve core 421 is generally a hollow cylindrical structure opening towards the valve cover 423, and an elastic element 427 abutting against the valve cover 423 is disposed within the valve core 421. An inlet 424 is provided at the bottom of the valve sleeve 422, and an outlet 425 communicating with the inlet 424 is provided on the side wall of the valve sleeve 422. A control port 426 is provided on the valve cover 423 for drilling fluid to enter the valve core 421.

[0060] In this embodiment, the elastic element 427 is a spring.

[0061] In some embodiments, when the force exerted by the drilling fluid at the inlet 424 on the bottom of the valve core 421 is less than the sum of the minimum elastic force of the elastic element 427 and the force exerted by the drilling fluid inside the valve core 421 on the valve core 421, the inlet 424 and the outlet 425 are blocked by the valve core 421. At this time, the control valve 42 is in the closed state. When the force exerted by the drilling fluid at the inlet 424 on the bottom of the valve core 421 is greater than the sum of the minimum elastic force of the elastic element 427 and the force exerted by the drilling fluid inside the valve core 421 on the valve core 421, the inlet 424 and the outlet 425 are connected. At this time, the control valve 42 is in the open state.

[0062] In this embodiment, the force exerted by the drilling fluid in the first chamber 13 on the bottom of the valve core 421 is greater than the sum of the minimum elastic force of the elastic element 427 and the force exerted by the drilling fluid in the second chamber 14 on the valve core 421. Therefore, when the first chamber 13 is in fluid communication with the control port 426 of the control valve 42 and the second chamber 14 is in fluid communication with the inlet port 424 of the control valve 42, the control valve 42 is in the closed state. When the first chamber 13 is in fluid communication with the inlet port 424 of the control valve 42 and the second chamber 14 is in fluid communication with the control port 426 of the control valve 42, the control valve 42 is in the open state.

[0063] Combination Figure 1 , Figure 4 and Figure 5 As shown, in some embodiments, the four control valves 42 are a first control valve 42a, a second control valve 42b, a third control valve 42c, and a fourth control valve 42d. The control ports of the first control valve 42a and the third control valve 42c are connected in parallel to the pilot valve 30, and the control ports of the second control valve 42b and the fourth control valve 42d are also connected in parallel to the pilot valve 30. The inlet of the first control valve 42a and the outlet of the second control valve 42b are connected in parallel to the first actuation chamber 211, and the inlet of the second control valve 42b and the inlet of the third control valve 42c are connected in parallel to the first chamber 13. The outlet of the third control valve 42c and the inlet of the fourth control valve 42d are connected in parallel to the second actuation chamber 212, and the outlet of the fourth control valve 42d and the outlet of the first control valve 42a are connected in parallel to the second chamber 14.

[0064] Combination Figure 4 As shown, the process of downhole booster 100 pressurizing downwards is as follows: Pilot valve 30 is in the first connected state. The control ports of the first control valve 42a and the third control valve 42c are fluidly connected to the first chamber 13 through pilot valve 30. The control ports of the second control valve 42b and the fourth control valve 42d are fluidly connected to the second chamber 14 through pilot valve 30. Drilling fluid entering the first chamber 13 through the upper connector 11 and the first guide element 111 will enter the first booster chamber 221 and the second booster chamber 231 through the first inlet valve 222 and the second inlet valve 232, respectively. Simultaneously, the drilling fluid in the first chamber 13 flows to the control ports of the first control valve 42a and the third control valve 42c, causing the first control valve 42a and the third control valve 42c to be in the closed state. Because the second chamber 14 is fluidly connected to the control port of the second control valve 42b and the control port of the fourth control valve 42d, the drilling fluid in the first chamber 13 flows to the inlet of the second control valve 42b, causing the second control valve 42b to be in the open state. The first chamber 13 is then fluidly connected to the first push chamber 211 through the second control valve 42b.

[0065] Because the fluid pressure in the first chamber 13 is greater than the fluid pressure in the second chamber 14, the piston 243 is driven by the pressure difference between the first push chamber 211 and the second push chamber 212, causing the piston rod 24 to move axially downwards. During this process, the volume of the first push chamber 211 continuously increases, allowing drilling fluid from the first chamber 13 to continuously enter the first push chamber 211 through the second control valve 42b. The volume of the second push chamber 212 continuously decreases, causing the drilling fluid pressure in the second push chamber 212 to increase, which then opens the fourth control valve 42d, allowing the drilling fluid in the second push chamber 212 to continuously flow to the second chamber 14 through the fourth control valve 42d.

[0066] As the first piston 241 moves downward with the piston rod 24, the volume of the first pressurization chamber 221 continuously increases, and the drilling fluid in the first chamber 13 continuously enters the first pressurization chamber 221 through the first inlet valve 222. Simultaneously, as the second piston 242 moves downward with the piston rod 24, the volume of the second pressurization chamber 231 continuously decreases, causing the drilling fluid in the second pressurization chamber 231 to flow through the second outlet valve 233 to the high-pressure nozzle of the drill bit after the pressure increases.

[0067] When the volume of the first push chamber 211 is at its maximum, the first piston 241 moves to the end of the first booster chamber 221 near the first push chamber 211. The first piston 241 pulls the valve stem 31 of the pilot valve 30 axially downward via the control component 33, causing the pilot valve 30 to switch to the second connected state. At this time, the downhole booster 100 finishes its downward boosting and begins its upward boosting.

[0068] Combination Figure 5 As shown, the process of the bottom-hole booster 100 performing upward pressurization is as follows: Pilot valve 30 is in the second connected state. The control ports of the second control valve 42b and the fourth control valve 42d are fluidly connected to the first chamber 13 through pilot valve 30. The control ports of the first control valve 42a and the third control valve 42c are fluidly connected to the second chamber 14 through pilot valve 30. The drilling fluid entering the first chamber 13 through the upper connector 11 and the first guide element 111 will enter the first booster chamber 221 and the second booster chamber 231 through the first inlet valve 222 and the second inlet valve 232, respectively. Simultaneously, the drilling fluid in the first chamber 13 flows to the control ports of the second control valve 42b and the fourth control valve 42d, causing the second control valve 42b and the fourth control valve 42d to be in the closed state. Since the second chamber 14 is fluidly connected to the control port of the first control valve 42a and the control port of the third control valve 42c, the drilling fluid in the first chamber 13 flows to the inlet of the third control valve 42c, causing the third control valve 42c to be in the open state. The first chamber 13 is then fluidly connected to the second push chamber 212 through the third control valve 42c.

[0069] Because the fluid pressure in the first chamber 13 is greater than the fluid pressure in the second chamber 14, the piston 243 is driven by the pressure difference between the first and second pushing chambers 211 and 212, causing the piston rod 24 to move axially upward. During this process, the volume of the second pushing chamber 212 continuously increases, allowing drilling fluid from the first chamber 13 to continuously enter the second pushing chamber 212 through the third control valve 42c. The volume of the first pushing chamber 211 continuously decreases, causing the drilling fluid pressure in the first pushing chamber 211 to increase, which then opens the first control valve 42a, allowing the drilling fluid in the first pushing chamber 211 to continuously flow to the second chamber 14 through the first control valve 42a.

[0070] As the second piston 242 moves upward with the piston rod 24, the volume of the second pressurization chamber 231 continuously increases, and the drilling fluid in the first chamber 13 continuously enters the second pressurization chamber 231 through the second inlet valve 232. Simultaneously, as the first piston 241 moves upward with the piston rod 24, the volume of the first pressurization chamber 221 continuously decreases, causing the drilling fluid in the first pressurization chamber 221 to flow through the first outlet valve 223 to the high-pressure nozzle of the drill bit after the pressure increases.

[0071] When the volume of the first push chamber 211 is at its minimum, the push piston 243 moves to the end of the first push chamber 211 near the first pressurization chamber 221. The push piston 243, through the control component 33, pushes the valve stem 31 of the pilot valve 30 to move axially upward, causing the pilot valve 30 to switch to the first connected state. At this time, the downhole booster 100 finishes its downward pressurization and begins its upward pressurization.

[0072] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0073] It should be understood that the terms "length", "width", "up", "down", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to 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 present invention.

[0074] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A downhole booster, comprising, a barrel (10) for connecting a drill bit, the barrel (10) being internally provided with a first chamber (13) for inputting drilling fluid and a second chamber (14) for outputting drilling fluid to the drill bit, the pressure in the first chamber (13) being greater than the pressure in the second chamber (14); a booster cylinder (20) for boosting and delivering the drilling fluid in the first chamber (13) to the drill bit, the booster cylinder (20) being internally provided with a piston assembly (240) for boosting and a first pushing chamber (211) and a second pushing chamber (212) separated by the piston assembly (240); a pilot valve (30) arranged in the barrel (10) for fluidly connecting the first chamber (13) and the second chamber (14); and a control valve assembly (40) arranged in the barrel (10) for fluidly connecting the pilot valve (30), wherein the pilot valve (30) being configured to fluidly connect the first pushing chamber (211) to the first chamber (13) and the second pushing chamber (212) to the second chamber (14) by the control valve assembly (40) when the piston assembly (240) makes the volume of the first pushing chamber (211) the smallest, so that the downhole booster (100) starts downhole boosting, and configured to fluidly connect the first pushing chamber (211) to the second chamber (14) and the second pushing chamber (212) to the first chamber (13) by the control valve assembly (40) when the piston assembly (240) makes the volume of the first pushing chamber (211) the largest, so that the downhole booster (100) starts uphole boosting.

2. The downhole pressure booster of claim 1, wherein, the control valve assembly (40) comprising a valve body (41) jointly separating the first chamber (13) and the second chamber (14) with the booster cylinder (20) and four control valves (42) mounted on the valve body (41), wherein the four control valves (42) are configured to fluidly connect the first pushing chamber (211) to the first chamber (13) when the volume of the first pushing chamber (211) is the smallest and fluidly connect the first pushing chamber (211) to the second chamber (14) when the volume of the first pushing chamber (211) is the largest.

3. The downhole pressure booster of claim 2, wherein, each of the control valves (42) comprising a valve sleeve (422) mounted on the valve body (41), a valve core (421) arranged in the valve sleeve (422), and a valve cover (423) connecting the valve sleeve (422), the bottom and the sidewall of the valve sleeve (422) being respectively provided with an inlet (424) and an outlet (425), the valve cover (423) being provided with a control port (426) fluidly connecting the valve core (421), the valve core (421) being internally provided with an elastic member (427) abutting against the valve cover (423), The minimum elastic force of the elastic member (427) and the force exerted on the valve core (421) by the drilling fluid in the second chamber (14) through the control port (426) are smaller than the force exerted on the valve core (421) by the drilling fluid in the first chamber (13) through the liquid inlet (424), so that the liquid inlet (424) is in communication with the liquid outlet (425).

4. The downhole pressure booster of claim 3, wherein, The four control valves (42) are respectively a first control valve (42a), a second control valve (42b), a third control valve (42c) and a fourth control valve (42d), the liquid inlet of the first control valve (42a) and the liquid outlet of the second control valve (42b) are in fluid communication with the first push chamber (211), the liquid inlets of the second control valve (42b) and the third control valve (42c) are in fluid communication with the first chamber (13), the liquid outlet of the third control valve (42c) and the liquid inlet of the fourth control valve (42d) are in fluid communication with the second push chamber (212), and the liquid outlet of the fourth control valve (42d) and the liquid inlet of the first control valve (42a) are in fluid communication with the second chamber (14).

5. The downhole pressure booster of claim 4, wherein, The pilot valve (30) is configured to make the control ports of the first control valve (42a) and the third control valve (42c) in fluid communication with the first chamber (13) and make the control ports of the second control valve (42b) and the fourth control valve (42d) in fluid communication with the second chamber (14) when down pressure boosting, And make the control ports of the first control valve (42a) and the third control valve (42c) in fluid communication with the second chamber (14) and make the control ports of the second control valve (42b) and the fourth control valve (42d) in fluid communication with the first chamber (13) when up pressure boosting.

6. The downhole pressure booster according to any of claims 1-5, characterized in that, A connecting rod (32) extending into the first push chamber (211) in the axial direction is connected to the valve rod (31) of the pilot valve (30), and a control member (33) is installed at one end of the connecting rod (32) in the first push chamber (211), The control member (33) is configured to move the connecting rod (32) in the axial direction by the piston assembly (240) when the volume of the first push chamber (211) is minimum or maximum, so as to adjust the pilot valve (30).

7. The downhole pressure booster according to claim 6, characterized in that The piston assembly (240) includes a piston rod (24) extending in the axial direction in the pressure boosting cylinder (20), a push piston (243) installed on the piston rod (24) and used to separate the first push chamber (211) and the second push chamber (212), and a first piston (241) and a second piston (242) installed at both ends of the piston rod (24) respectively, The control member (33) is configured to be pushed in the axial upward direction by the push piston (243) or in the axial downward direction by the first piston (241), so that the connecting rod (32) can move in the axial direction.

8. The downhole pressure booster according to claim 7, characterized in that The booster cylinder (20) is further provided with a first booster chamber (221) separated from the first pushing chamber (211) by the first piston (241), and a second booster chamber (231) separated from the second pushing chamber (212) by the second piston (242), the first booster chamber (221) and the second booster chamber (231) being respectively communicated with the first chamber (13) through a first liquid inlet valve (222) and a second liquid outlet valve (233) installed on the booster cylinder (20), the first booster chamber (221) and the second booster chamber (231) being respectively communicated with the drill bit through a first liquid outlet valve (223) and a second liquid outlet valve (233) installed on the booster cylinder (20).

9. The downhole pressure booster according to claim 8, characterized in that The first liquid inlet valve (222) and the first liquid outlet valve (223) are both one-way valves, so that the drilling fluid in the first chamber (13) can enter the first booster chamber (221) through the first liquid inlet valve (222) during the volume increase of the first pushing chamber (211).

10. The downhole pressure booster according to claim 9, characterized in that The cross-sectional area of the pushing piston (243) is greater than that of the first piston (241), so that the drilling fluid in the first booster chamber (221) can be boosted and flow to the drill bit through the first liquid outlet valve (223) during the volume decrease of the first pushing chamber (211).

11. The downhole pressure booster of claim 8, wherein, The second liquid inlet valve (232) and the second liquid outlet valve (233) are also both one-way valves, so that the drilling fluid in the first chamber (13) can enter the second booster chamber (231) through the first liquid inlet valve (222) during the volume decrease of the first pushing chamber (211).

12. The downhole pressure booster of claim 11, wherein, The cross-sectional area of the pushing piston (243) is greater than that of the second piston (242), so that the drilling fluid in the second booster chamber (231) can be boosted and flow to the drill bit through the second liquid outlet valve (233) during the volume increase of the first pushing chamber (211).

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