Flow rate control system and method

Abstract

The flow rate control system includes a housing and a valve assembly slidably disposed within a bore of the housing. The housing includes a bypass opening. The valve assembly includes a valve and an orifice disposed within a bore of the valve. The valve includes a plurality of valve bypass holes extending axially through a valve collar. The valve assembly slides between a closed position and a fully open position. A spring biases the valve assembly toward the closed position, in which the valve closes the housing bypass opening. In the open position, a bypass fluid path is formed including the valve bypass holes and the housing bypass opening. The valve assembly is flow rate controlled in the closed position and pressure controlled in the open position. The valve assembly can slide within a sleeve assembly including a sleeve bypass opening connecting the valve bypass holes in the bypass fluid path and the housing bypass opening.

Description

[0001] background

[0002] During the drilling process of oil and gas wells, downhole drilling motors can be connected to the drill string to rotate and manipulate the drill bit. Conventional drilling motors typically provide rotation using a power section, which can be a positive displacement motor driven by the circulation of drilling fluid or drilling mud.

[0003] As wells are drilled faster, higher drilling fluid flow rates are required to remove drill cuttings from the wellbore. Each drilling motor is designed to operate at the maximum drilling fluid flow rate. For example, a conventional drilling motor with a 6.75-inch outer diameter can be designed for a maximum flow rate of approximately 600 gallons per minute (GPM). Exceeding the drilling motor's maximum flow rate can cause premature failure of bearing sections due to corrosion.

[0004] Existing tools can divert some or all of the drilling fluid above the drilling motor to reduce its flow rate before it reaches the motor. By using a tool to bypass all drilling fluid into the annulus, the fluid can be diverted to a different medium (such as LCM drilling fluid or even fracturing fluid). Some diverter tools include passive valves, which are activated by a separate mechanism. For example, a ball, dart, or RFID device inserted into the surface drilling fluid engages with a container upon reaching the diverter tool, and this interaction opens the valve to begin diverting the drilling fluid into the well annulus above the drilling motor. However, these passive valve tools have a 10- to 15-minute delay between the moment of action (e.g., the ball or dart falls to the surface) and the moment the valve opens. This delay increases the cost of the wellbore.

[0005] Other bypass steering tools include active valves that automatically activate in response to downhole parameters. For example, changes in flow rate, pressure, density, or rotational speed to a predetermined threshold automatically open the valve to divert a portion of the drilling fluid into the annulus above the drilling motor. However, these active valve tools can sometimes be inadvertently activated by downhole parameter changes unrelated to surface activation, such as vibration, bit blockage, or motor stall. There is a need for an active valve tool that, without accidental activation, diverts a portion of the fluid flowing through the drill string into the annulus. Summary of the Invention

[0006] This disclosure provides the following items:

[0007] 1. A flow rate control system, comprising:

[0008] A housing, the housing including one or more housing bypass openings extending radially from an inner housing bore to an outer surface of the housing;

[0009] A valve assembly slidably disposed within a housing bore, the valve assembly including a valve and an orifice; wherein the valve includes a valve collar defining an upper surface of the valve and defining an outer collar surface and a lower collar surface, a lower valve shoulder, a diameter-decreasing outer surface extending from the lower collar surface to the lower valve shoulder, a valve bore extending axially from the upper surface to a lower end, and a plurality of valve bypass holes extending axially through the valve collar between the valve bore and the outer collar surface; wherein the orifice is disposed within the valve bore; and wherein the valve assembly is configured to slide between a closed position and a fully open position;

[0010] A spring disposed in the housing bore and surrounding a portion of the valve assembly, wherein the spring biases the valve assembly toward the closed position;

[0011] In the closed position, the valve closes the housing bypass opening, and in the closed position, the valve assembly is subject to flow rate control.

[0012] In the partially open position and the fully open position, the bypass fluid path is formed by the valve bypass orifice and the housing bypass opening; and in the partially open position and the fully open position, the valve assembly is pressure controlled.

[0013] 2. The flow control system according to Project 1, wherein each of the valve bypass orifices extends from an inlet on the upper surface of the valve to an outlet on the lower collar surface.

[0014] 3. The flow rate control system according to Project 1, wherein the orifice is formed by an orifice ring disposed in the inner hole of the valve.

[0015] 4. The flow rate control system according to Project 1 further includes a sleeve assembly statically fixed in the inner bore of the housing; wherein the valve assembly is slidably disposed through the sleeve assembly; wherein the sleeve assembly includes a valve sleeve disposed around the valve, the valve sleeve including a reduced diameter section and a plurality of valve sleeve bypass openings extending radially from the inner bore to the outer surface of the reduced diameter section, wherein the bypass fluid path in the fully open position further includes the valve sleeve bypass openings.

[0016] 5. The flow control system according to item 4 further includes one or more damping chambers formed between the valve assembly and the sleeve assembly, wherein one or more damping nozzles fluidly connect the inner bore of the valve assembly to the one or more damping chambers to slow down the sliding movement of the valve assembly in the sleeve assembly.

[0017] 6. The flow rate control system according to Project 4, wherein a metal-to-metal seal is formed between the valve sleeve and the valve.

[0018] 7. The flow rate control system according to Project 4, wherein the bypass fluid path in the partially open position and the fully open position further includes an internal bypass chamber defined between the valve sleeve and the outer surface of the valve with a reduced diameter, wherein, in the partially open position and the fully open position, the internal bypass chamber is fluidly connected to the valve bypass orifice and the valve sleeve bypass opening.

[0019] 8. The flow control system according to item 7, wherein the bypass fluid path in the partially open position and the fully open position further includes an external bypass chamber defined between the reduced diameter section of the housing and the valve sleeve, wherein, in all positions, the external bypass chamber is fluidly connected to the valve sleeve bypass opening and the housing bypass opening.

[0020] 9. The flow rate control system according to item 8, wherein the valve assembly further includes a spring spindle disposed below the valve and the orifice, the spring spindle including an inner bore and an upper end engaging the inner bore of the valve, wherein the spring is disposed around the outer surface of the spring spindle, and wherein the spring biases the spring spindle toward the closed position to bias the valve toward the closed position.

[0021] 10. The flow control system according to item 9, wherein the spring spindle includes a sealing block having an outer surface with an enlarged diameter, wherein the spring biases the sealing block toward the closed position.

[0022] 11. The flow rate control system according to item 10 further includes a spring sleeve disposed in the inner hole of the housing and surrounding the spring spindle and the spring.

[0023] 12. The flow rate control system according to item 11, wherein the sealing block defines an upper damping chamber and a lower damping chamber between the spring mandrel and the spring sleeve, the sealing block comprising at least one upper nozzle for fluidly connecting the inner bore of the spring mandrel to the upper damping chamber and at least one lower nozzle for fluidly connecting the inner bore of the spring mandrel to the lower damping chamber.

[0024] 13. The flow rate control system according to Project 12 further includes an upper spring ring and a lower spring ring, each of which is disposed around the outer surface of the spring spindle, wherein the upper spring ring is disposed between the sealing block of the spring spindle and the upper end of the spring, and wherein the lower spring ring is disposed between the lower end of the spring and the lower shoulder of the spring sleeve.

[0025] 14. The flow rate control system according to item 13, wherein the upper spring ring and the spring are disposed in the lower damping chamber, wherein an annular space is formed between the upper spring ring and the spring sleeve.

[0026] 15. A method for controlling the flow rate of fluid to a drilling motor, comprising the following steps:

[0027] a) Providing a flow rate control system, the flow rate control system comprising: a housing including one or more housing bypass openings extending radially from an inner bore of the housing to an outer surface of the housing; a valve assembly slidably disposed within the inner bore of the housing, the valve assembly including a valve and orifices; wherein the valve includes a valve collar defining an upper surface of the valve and defining an outer collar surface and a lower collar surface, a lower valve shoulder, a diameter-decreasing outer surface extending from the lower collar surface to the lower valve shoulder, a valve inner bore extending axially from the upper surface to a lower end, and a plurality of valve bypass orifices extending axially through the valve collar between the valve inner bore and the outer collar surface; wherein the An orifice is disposed within the valve bore; and wherein the valve assembly is configured to slide between a closed position and a fully open position; a spring is disposed within the housing bore and surrounds a portion of the valve assembly, wherein the spring biases the valve assembly toward the closed position; wherein, in the closed position, the valve closes the housing bypass opening, and wherein, in the closed position, the valve assembly is subject to flow rate control; wherein, in the partially open position and the fully open position, a bypass fluid path is formed by the valve bypass orifice and the housing bypass opening; and wherein, in the partially open position and the fully open position, the valve assembly is subject to pressure control;

[0028] b) Attach the flow rate control system to the tubing above the drilling motor;

[0029] c) With the valve assembly in the closed position, pump fluid through the flow rate control system so that substantially all of the fluid flows through the valve bore to the drilling motor;

[0030] d) Increase the flow rate of the fluid above a threshold flow rate value so that the valve assembly slides in the downward direction to the partially open position, in which a portion of the fluid flows through the bypass fluid path into the annular space surrounding the housing.

[0031] 16. The method according to item 15 further includes the following steps:

[0032] e) When the flow rate control system is in the partially open position, the flow rate of the fluid passing through the flow rate control system is reduced to below a threshold flow rate value without sliding the valve assembly to the closed position.

[0033] 17. The method according to item 15 further includes the following steps:

[0034] e) Maintain or increase the pressure difference between the fluid flowing into the flow rate control system and the fluid in the annular space, so that the valve assembly slides further in the downward direction to the fully open position, thereby increasing the flow of the fluid through the bypass fluid path into the portion of the annular space.

[0035] 18. The method according to item 17 further includes the following steps:

[0036] f) Reduce the pressure difference between the fluid flowing into the flow rate control system and the fluid in the annular space, so that the valve assembly slides upward to the partially open position, thereby reducing the volume of the fluid flowing through the bypass fluid path into the portion of the annular space.

[0037] 19. The method according to item 18 further includes the following steps:

[0038] g) Further reduce the pressure difference between the fluid flowing into the flow rate control system and the fluid in the annular space, so that the valve assembly slides further in the upward direction to the closed position.

[0039] 20. The method according to item 15, wherein the flow rate control system further includes a sleeve assembly statically fixed in the inner bore of the housing, the valve assembly being slidably disposed through the sleeve assembly, wherein the flow rate control system further includes one or more damping chambers formed between the valve assembly and the sleeve assembly, wherein the one or more damping chambers are fluidly connected to the inner bore of the valve assembly via one or more nozzles; and wherein, in step (d), the one or more damping chambers slow down the sliding movement of the valve assembly.

[0040] 21. The method according to item 15 further includes the following steps:

[0041] e) The flow rate control system is placed in a fully bypassed position, in which all fluid flowing into the flow rate control system is transferred through the bypass fluid path to the annular space surrounding the housing above the drilling motor.

[0042] 22. The method according to item 21, wherein the fluid flowing into the flow rate control system at the fully bypassed position is an LCM-rich drilling fluid, perforation fluid, or fracturing fluid. Brief description of the attached diagram

[0044] Figure 1 This is a cross-sectional view of the flow control system in the closed position.

[0045] Figure 2 This is a detailed cross-sectional view of a part of a flow control system in the closed position.

[0046] Figure 3 This is an isometric view of the valve sleeve of the flow rate control system.

[0047] Figure 4 This is another isometric view of the valve sleeve.

[0048] Figure 5 This is an isometric view of the valve in the flow rate control system.

[0049] Figure 6 This is another isometric view of the valve.

[0050] Figure 7 This is a cross-sectional view of the valve.

[0051] Figure 8 This is a cross-sectional view of the valve and orifice ring.

[0052] Figure 9 This is an isometric view of the spring spindle of the flow rate control system.

[0053] Figure 10 This is a schematic diagram of the flow velocity control system installed in the tubing string inside the wellbore.

[0054] Figure 11 This is a cross-sectional view of the flow control system in the partially open position.

[0055] Figure 12 This is a detailed cross-sectional view of a part of a flow control system in a partially open position.

[0056] Figure 13 This is a cross-sectional view of the flow control system in the fully open position.

[0057] Figure 14 This is a detailed cross-sectional view of a flow control system in the fully open position.

[0058] Detailed description of the selected embodiments

[0059] A flow rate control system includes a valve assembly slidably disposed within a housing. The valve assembly slides between a closed position, a partially open position, and a fully open position. A spring applies a spring force to bias the valve assembly toward the closed position. The valve assembly is subject to flow rate control in the closed position and pressure control in the fully open position.

[0060] In one embodiment, the flow control system further includes a sleeve assembly fixed within the housing. The valve assembly is slidably disposed within the sleeve assembly to slide between a closed position, a partially open position, and a fully open position.

[0061] In the closed position, the fluid flowing through the system exerts a force on the first active valve region. An increase in fluid velocity exerts an increased force on the first active valve region. When the increased force exceeds a threshold that overcomes the spring force, the valve assembly begins to slide toward the partially open position. When the valve assembly reaches the partially open position, a portion of the fluid can begin to flow through a bypass fluid path that leads to the annular space surrounding the housing. In this way, the flow rate control system ensures that the flow rate of the fluid toward the drilling motor located below (i.e., downstream) does not exceed the maximum flow rate allowed by the drilling motor design. Alternatively, excess fluid flow is diverted to the annular space surrounding the housing via the bypass fluid path. The valve assembly has a second active valve region that becomes active in the partially open position and remains active in the fully open position. The second active valve region is downwardly biased by the pressure difference between the inner bore of the valve assembly and the annular space surrounding the housing. In both the partially open and fully open positions, the pressure in the system exerts a downward force on the second active valve region. When the bypass fluid flow begins in the partially open position, the force applied to the second active valve region causes the valve assembly to continue moving toward the fully open position and prevents the valve assembly from closing.

[0062] In one embodiment, the valve assembly includes a valve bypass port that provides fluid communication through a valve collar. In the closed position, the pressure above the valve collar is equal to the pressure below the valve collar. Therefore, the valve assembly is flow-controlled in the closed position. However, in the partially open and fully open positions, the valve bypass port is in fluid communication with an annular space surrounding the housing, such that the pressure below the valve collar is less than the pressure above the valve collar. Therefore, the valve assembly is a pressure-controlled valve in both the partially open and fully open positions.

[0063] Accordingly, if fluid pumping temporarily stops or slows down (e.g., pump stops, drill bit gets clogged, or motor stalls), the valve assembly will not change position (i.e., the valve assembly will not return to the closed position) until the pressure difference between the interior of the flow control system and the annular space surrounding the housing decreases. Increasing the pressure within the annular space, decreasing the pressure within the drill string, or allowing pressure to be equalized through the bypass fluid path allows the spring to begin closing the valve, which applies a force to the valve assembly in an upward direction toward the closed position. When this upward force exceeds the force applied in a downward direction to the second active valve region, the valve assembly moves back to the closed position.

[0064] In one embodiment, the flow control system includes a damping chamber disposed between the valve assembly and the sleeve assembly. A damping nozzle on the radial surface of the valve assembly allows fluid communication between the inner bore of the valve assembly and the damping chamber to slow the sliding movement of the valve assembly relative to the sleeve assembly.

[0065] In one embodiment, the flow rate control system may include a fully bypass position in which the orifice of the valve assembly is completely closed below the bypass fluid path. In this fully bypass position, all drilling fluid flowing through the system is diverted to the annular space, and the drilling fluid ceases to flow towards the downward-facing motor. When the flow rate control system is in the fully bypass position, the drilling fluid can be replaced by other types of fluids, such as LCM fluid, perforation fluid, or fracturing fluid.

[0066] Figure 1 and Figure 2 An embodiment of a flow rate control system in the closed position is shown. The flow rate control system 10 includes an upper sub 12, a housing 14, and a lower sub 16, each having a generally tubular shape with an inner bore. The upper end of the upper sub 12 can be configured to connect to a tubular member within the drill string. The upper end of the housing 14 can connect to the lower end of the upper sub 12, and the lower end of the housing 14 can connect to the upper end of the lower sub 16. The lower end of the lower sub 16 can be configured to connect to a tubular member within the drill string. In one embodiment, each of these connections is a threaded connection. The flow rate control system can be fixed in the drill string above a bottom hole assembly including a drilling motor.

[0067] The flow control system 10 may include a sleeve assembly 17 fixed within a housing bore 18 and a valve assembly 19 slidably disposed within the sleeve assembly 17. The sleeve assembly 17 may include a valve sleeve 20, a valve stop 22, and a spring sleeve 24. An upper ring 26 may be fixed within the housing bore 18 between the upper end of the valve sleeve 20 and the lower end of the upper connector 12. Thus, the sleeve assembly 17 is fixed within the housing bore 18 between the upper ring 26 and the lower housing shoulder 28. The valve assembly 19 may include a valve 30, an orifice ring 32, and a spring spindle 34. A spring 36, a lower spring ring 38, and an upper spring ring 40 may each be disposed around the spring spindle 34 and within the spring sleeve 24. The lower end of the spring 36 may engage the lower spring ring 38, and the upper end of the spring 36 may engage the upper spring ring 40. The housing 14 may include one or more housing bypass openings 41 extending radially from the housing bore 18 to the outer surface of the housing 14. The housing 14 may include any number of housing bypass openings 41. For example, the housing 14 may include one to ten housing bypass openings 41. The valve sleeve 20 is aligned with one or more housing bypass openings 41 in the housing bore 18, and the valve 30 is slidably disposed in the bore of the valve sleeve 20.

[0068] Reference Figure 3 and Figure 4 Valve sleeve 20 has a generally tubular shape and extends from an upper end 42 to a lower end 44. An upper outer surface 46 of valve sleeve 20 extends from the upper end 42 to a tapered shoulder 48. The upper outer surface 46 may include a groove 50 configured to receive an O-ring or other sealing mechanism for providing a fluid seal between valve sleeve 20 and housing 14. A diameter-reducing section 52 extends from the tapered shoulder 48 to a shoulder 54 of the lower outer surface 56. The diameter-reducing section 52 includes a plurality of valve sleeve bypass openings 58 near the shoulder 54. Each valve sleeve bypass opening 58 extends radially from an inner bore 60 to the outer surface of valve sleeve 20. Valve sleeve 20 may include any number of valve sleeve bypass openings 58. For example, valve sleeve 20 may include 1 to 50 valve sleeve bypass openings 58. The lower outer surface 56 extends from the shoulder 54 to the lower end 44. The lower outer surface 56 may include a groove 62 configured to receive an O-ring or other sealing mechanism for providing a fluid seal between the valve sleeve 20 and the housing 14. An inner bore 60 extends from the upper end 42 to the lower end 44.

[0069] Now refer to Figure 2A valve sleeve 20 may be disposed within a housing bore 18, wherein a reduced-diameter section 52 of the valve sleeve 20 is aligned with one or more housing bypass openings 41. An external bypass chamber 66 between the valve sleeve 20 and the housing 14 may be defined by the housing bore 18 and the reduced-diameter section 52. The upper end of the external bypass chamber 66 may be defined by a tapered shoulder 48 of the valve sleeve 20, and the lower end of the external bypass chamber 66 may be defined by a shoulder 54 of the valve sleeve 20. The external bypass chamber 66 may fluidly connect a plurality of valve sleeve bypass openings 58 and one or more housing bypass openings 41. In one embodiment, one or more housing bypass openings 41 may be located near the upper end of the external bypass chamber 66, and the plurality of valve sleeve bypass openings 58 may be located near the lower end of the external bypass chamber 66. The bore 60 of the valve sleeve 20 includes an inner tapered shoulder 67 and an inner groove 68 surrounding the plurality of valve sleeve bypass openings 58.

[0070] Now refer to Figures 5 to 8 Valve 30 has a generally tubular shape and extends from an upper surface 72 to a lower end 74. A valve collar 76 extends from the upper surface 72 to a lower collar surface 78. In one embodiment, the lower collar surface 78 is a tapered surface. The outer collar surface 80 may include a groove 82 configured to receive an O-ring or other sealing mechanism for providing a fluid seal between valve 30 and valve sleeve 20. A plurality of valve bypass holes 84 extend axially through valve collar 76. Each valve bypass hole 84 extends from an inlet 86 on the upper surface 72 to an outlet 88 on the lower collar surface 78. Valve 30 may include any number of valve bypass holes 84. For example, valve 30 may include 1 to 50 valve bypass holes 84. A tapered section 90 extends from the lower collar surface 78 to a lower valve shoulder 92. A lower outer surface 94 extends from the lower valve shoulder 92 to the lower end 74 of valve 30. The lower outer surface 94 may include a groove 96 configured to receive an O-ring or other sealing mechanism for providing a fluid seal between the valve 30 and the valve sleeve 20. The outer ring surface 80 may have an expanded diameter B, which is larger than the sealing diameter A of the lower outer surface 94. Figure 8 The sealing diameter A of the lower outer surface 94 and the enlarged diameter B of the outer ring surface 80 and the upper surface 72 are shown. The portion of the upper surface 72 extending beyond the sealing diameter A of the lower outer surface 94 may be referred to as the peripheral upper surface 97. In one embodiment, the peripheral upper surface 97 includes a beveled portion. A valve bore 98 extends from the upper surface 72 to the lower end 74. The valve bore 98 includes an inner shoulder 100 and a tapered surface 102 extending to a lower groove 104. The valve bore 98 may also include a recess 106 configured to receive an O-ring or other sealing mechanism for providing a fluid seal between the valve 30 and the spring spindle 34. A valve bypass port 84 is provided between the valve bore 98 and the outer ring surface 80.

[0071] Reference Figure 2 and Figures 7 to 8 The valve 30 is slidably disposed within the inner bore 60 of the valve sleeve 20. In the closed position, both the upper surface 72 of the valve 30 and the upper end 42 of the valve sleeve 20 can directly engage the lower surface of the upper ring 26. In the closed position, the peripheral upper surface 97 can be located directly below the upper ring 26.

[0072] Refer again Figure 2 A sliding hydraulic seal can be formed at interface 108 between valve 30 and valve sleeve 20. The sliding hydraulic seal can be formed by a metal-to-metal interface. An internal bypass chamber 110 between valve 30 and valve sleeve 20 can be defined by the inner bore 60 of valve sleeve 20 and the reduced diameter section 90 of valve 30. The upper end of the internal bypass chamber 110 can be defined by the lower collar surface 78, and the lower end of the internal bypass chamber 110 can be defined by the lower valve shoulder 92. The internal bypass chamber 110 is in fluid communication with the valve bypass port 84. Figure 2 In the closed position shown, valve 30 closes the housing bypass opening 41 and the valve sleeve bypass opening 58 to prevent bypass fluid flow. Correspondingly, most of the fluid flowing through the inner bore of the upper ring 26 flows through the valve inner bore 98. In the partially open and fully open positions (described below), the internal bypass chamber 110 can be in fluid communication with the plurality of valve sleeve bypass openings 58 and housing bypass openings 41 to form a bypass fluid path in an annular space from the interior of the flow control system 10 to the exterior of the housing 14.

[0073] like Figure 2 As shown, the orifice ring 32 can be disposed in the valve bore 98 such that the upper surface of the orifice ring 32 engages with the inner shoulder 100 of the valve bore 98. The orifice ring 32 includes an orifice bore 112, which may have a smaller diameter than the valve bore 98 above the orifice ring 32.

[0074] Now refer to Figure 9The spring spindle 34 has a generally tubular shape and extends from an upper end 114 to a lower end 116. An inner bore 118 of the spring spindle 34 also extends from the upper end 114 to the lower end 116. The spring spindle 34 includes a sealing block 120, which has an enlarged outer diameter relative to the rest of the spring spindle 34. The sealing block 120 includes an upper nozzle surface 122, a central outer surface 124, and a lower nozzle surface 126. One or more upper nozzles 128 may extend radially from the inner bore 118 to the upper nozzle surface 122 on the sealing block 120. One or more lower nozzles 130 may extend radially from the inner bore 118 to the lower nozzle surface 126 on the sealing block 120. The spring spindle 34 may include any number of upper nozzles 128 and lower nozzles 130. For example, the spring spindle 34 may include one to ten upper nozzles 128 and one to ten lower nozzles 130. The central outer surface 124 has an outer diameter larger than that of the upper nozzle surface 122 and the lower nozzle surface 126. The central outer surface 124 may include a groove 131 configured to receive an O-ring or other sealing mechanism for providing a fluid seal (e.g., between the spring spindle 34 and the spring sleeve 24) Figure 2 (As shown). The spring spindle 34 may also include one or more ports 132 extending radially from the inner bore 118 to the outer surface above the sealing block 120. The spring spindle 34 may include any number of ports 132. For example, the spring spindle 34 may include 1 to 10 ports 132.

[0075] Refer again Figure 2 The upper end 114 of the spring spindle 34 is disposed within the valve bore 98, such that the upper end 114 engages with the lower surface of the orifice ring 32. One or more ports 132 of the spring spindle 34 can be aligned with the lower groove 104 of the valve bore 98. The spring spindle 34 can pass through the inner hole of the valve stop 22, and the sealing block 120 is disposed below the valve stop 22.

[0076] A valve stop 22 is disposed in a housing bore 18 below the valve sleeve 20. The valve stop 22 may be formed of a generally tubular ring. The bore of the valve stop 22 may include a groove 136 configured to receive an O-ring or other sealing mechanism for providing a fluid seal between the spring spindle 34 and the valve stop 22. In one embodiment, in the closed position, the upper end of the sealing block 120 engages the lower end of the valve stop 22. Port 132 and lower groove 104 provide fluid communication between the bore 118 of the spring spindle 34 and the valve chamber 138. In the closed position, the valve chamber 138 may be formed between the valve sleeve 20 and the spring spindle 34. The upper end of the valve chamber 138 may be formed by the lower end 74 of the valve 30, and the lower end of the valve chamber 138 may be formed by the upper surface of the valve stop 22.

[0077] Refer again Figure 1 and Figure 2A spring sleeve 24 is disposed within a housing bore 18 below the valve stop 22. The spring sleeve 24 may have a generally tubular shape. An inner bore 142 of the spring sleeve 24 may extend from an upper end 144 to a lower end 146. The inner bore 142 may include a spring sleeve shoulder 148 near the lower end 146. A spring spindle 34 may be disposed through the inner bore 142 of the spring sleeve 24. In all locations, the lower end 116 of the spring spindle 34 may extend beyond the lower end 146 of the spring sleeve 24. The inner bore 142 of the spring sleeve 24 may also include a groove 150 configured to receive an O-ring or other sealing mechanism for providing a fluid seal between the spring spindle 34 and the spring sleeve 24. The lower end 146 of the spring sleeve 24 engages the lower housing shoulder 28.

[0078] The upper spring ring 40 can be disposed around the spring spindle 34. The upper surface of the upper spring ring 40 can directly engage the lower surface of the sealing block 120 of the spring spindle 34. The lower surface of the upper spring ring 40 can directly engage the upper end of the spring 36. The upper spring ring 40 can have a generally tubular shape, and its inner diameter can be designed to receive the spring spindle 34. The outer diameter of the upper spring ring 40 can be designed to provide an annular space 152 between the outer surface 154 of the upper spring ring 40 and the inner hole 142 of the spring sleeve 24.

[0079] The lower spring ring 38 may also be arranged around the spring spindle 34. The upper surface of the lower spring ring 38 may directly engage the lower end of the spring 36. The lower surface of the lower spring ring 38 may directly engage the shoulder 148 of the spring sleeve. The lower spring ring 38 may have a generally tubular shape, and its inner diameter may be designed to receive the spring spindle 34. The outer diameter of the lower spring ring 38 may be designed to fit within the inner hole 142 of the spring sleeve 24 above the shoulder 148 of the spring sleeve.

[0080] Spring 36 applies an upward spring force to valve assembly 19. Specifically, spring 36 applies an upward force to upper spring ring 40, which transmits the upward spring force to sealing block 120 of spring spindle 34. Upper end 114 of spring spindle 34 transmits the upward spring force to orifice ring 32, which transmits the upward spring force to valve 30 via inner shoulder 100. In other words, the spring force biases upper spring ring 40, spring spindle 34, orifice ring 32, and valve 30 toward the closed position. The upward movement of valve assembly 19 can be limited by upper surface 72 of valve 30, which engages with the lower surface of upper ring 26. The upward movement of valve assembly 19 can also be limited by upper end of sealing block 120 of spring spindle 34, which engages with the lower surface of valve stop 22. Due to this upward spring force, the default position of flow rate control system 10 without fluid flow is... Figure 1 and Figure 2 The indicated closing position.

[0081] Still refer to Figure 1 and Figure 2 An upper damping chamber 160 and a lower damping chamber 162 can be formed between the spring spindle 34 and the spring sleeve 24. The upper end of the upper damping chamber 160 can be defined by the lower surface of the valve stop 22, and the lower end of the upper damping chamber 160 can be defined by the central outer surface 124 of the sealing block 120 of the spring spindle 34. The upper end of the lower damping chamber 162 can be defined by the central outer surface 124 of the sealing block 120, and the lower end of the lower damping chamber 162 can be defined by the spring sleeve shoulder 148 of the spring sleeve 24. In this way, the central outer surface 124 separates the upper damping chamber 160 and the lower damping chamber 162. In other words, the central outer surface 124 forms a damping chamber seal. In one embodiment, the upper spring ring 40, the spring 36, and the lower spring ring 38 are disposed in the lower damping chamber 162.

[0082] One or more upper nozzles 128 provide fluid communication between the inner bore 118 of the spring spindle 34 and the upper damping chamber 160. One or more lower nozzles 130 provide fluid communication between the inner bore 118 of the spring spindle 34 and the lower damping chamber 162. When fluid begins to flow through the inner bore 118 of the spring spindle 34, a small portion of the fluid may flow through the nozzles 128, 130 to fill the upper damping chamber 160 and the lower damping chamber 162, respectively. The upper nozzles 128 and lower nozzles 130 may be configured to provide a volumetric fluid flow rate between the inner bore 118 of the spring spindle 34 and the upper damping chamber 160 and the lower damping chamber 162. As the valve assembly 19 moves upward or downward, the volume of the upper damping chamber 160 and the lower damping chamber 162 changes. The rate at which fluid moves into or out of the upper damping chamber 160 and the lower damping chamber 162 controls the speed at which the valve assembly 19 moves between the open and closed positions. In one embodiment, the upper nozzle 128 and the lower nozzle 130 each include a reduced diameter section to restrict fluid flow based on the sum of the force from the spring 36 acting on the valve assembly 19 and the pressure difference generated by the fluid flowing through the valve assembly 19.

[0083] Reference Figure 10 The flow control system 10 can be fixed below the tubing string 180. The bottom hole assembly, including the drilling motor 182 and drill bit 184, can be fixed below the flow control system 10. The tubing string 180, the flow control system 10, and the components fixed below can be lowered into a wellbore 186 extending below the surface 188 and through the subsurface formation 190. When the flow control system 10 is in... Figure 1 and Figure 2In the closed position shown, virtually all fluid flowing through the tubing passes through the flow rate control system 10 to the drilling motor 182. Specifically, fluid can flow through the inner bore of the upper connector 12, the inner bore of the upper ring 26, the valve inner bore 98, the orifice inner bore 112, the inner bore 118 of the spring spindle 34, the housing inner bore 18 below the spring spindle 34, and the inner bore of the lower connector 16. A negligible amount of fluid can leak through the sealing devices in the flow rate control system 10. The fluid flowing through the drilling motor 182 causes the drill bit 184 to rotate to further drill the wellbore 186. The drill bit 184 breaks the formation 190 into drill cuttings. The fluid flowing through the drilling motor 182 and the drill bit 184 transports the drill cuttings to the surface 188 through the wellbore annular space 192.

[0084] Refer again Figure 1 , Figure 2 and Figure 8 When the fluid flowing through the flow rate control system 10 is in the closed position, it exerts a downward force on the first active valve region C of the valve assembly 19. The first active valve region C is defined by the cross-sectional area of ​​the valve assembly 19 located between the lower outer surface 94 and the inner hole 112 of the orifice ring 32. Figure 8 A first active valve region C is shown, and the first active valve region C includes a portion of the upper surface 72 of valve 30, the lower valve shoulder 92 of valve 30, and a portion of the upper surface of orifice ring 32, which are disposed between the lower outer surface 94 and the inner hole 112 of orifice ring 32. This area is equal to the cross-sectional area of ​​valve assembly 19 minus the cross-sectional area of ​​the peripheral upper surface 97. A portion of the fluid flows through valve bypass orifice 84 to fill the closed internal bypass chamber 110. In the closed position, the pressure in the upper ring 26 (i.e., the pressure above valve sleeve 76) is approximately equal to the pressure in the internal bypass chamber 110 (i.e., the pressure below valve sleeve 76). Therefore, the flow rate control system 10 is flow rate controlled in the closed position. "Flow rate control" refers to the pressure difference across valve assembly 19 caused by changes in the flow rate of fluid flowing through flow rate control system 10, which generates a downward force acting on the first active valve region C of valve assembly 19 to slide from the closed position to the partially open position. A portion of the fluid may also flow through port 132 of spring spindle 34 and through lower groove 104 of valve 30 to prevent hydraulic locking and allow fluid in valve chamber 138 to drain into inner bore 118. A portion of the fluid may also flow through upper nozzle 128 and lower nozzle 130 to fill or empty upper damping chamber 160 and lower damping chamber 162, respectively.

[0085] Refer again Figure 1 and Figure 2The increased flow rate of the fluid flowing through the flow rate control system 10 in the closed position applies an increased downward force to the first active valve region C of the valve assembly 19. When the downward force reaches a predetermined threshold force value that overcomes the upward spring force on the valve assembly 19, the downward force causes the valve assembly 19 to slide in a downward direction within the sleeve assembly 17 and the housing 14, compressing the spring 36. Specifically, the valve 30 slides downward within the valve sleeve 20, and the spring spindle 34 slides downward within the valve sleeve 20 and the spring sleeve 24.

[0086] For the spring spindle 34 to slide downwards, a portion of the fluid in the lower damping chamber 162 must return to the inner bore 118 of the spring spindle 34 through the lower nozzle 130, and more fluid must enter the upper damping chamber 160 through the upper nozzle 128. The restricted diameters of the nozzles 128 and 130 delay the movement of the valve assembly 19 in response to changes in fluid velocity. Thus, the damping chambers provide damping for the movement of the valve assembly 19. The valve assembly 19 slides in response to average fluid velocity over time rather than short-duration changes or faster fluctuations. As the valve 30 and spring spindle 34 slide downwards, the fluid in the valve chamber 138 must also return to the inner bore 118 of the spring spindle 34.

[0087] Valve assembly 19 slides downward in response to an increased fluid flow rate until it reaches... Figure 11 and Figure 12 The partial open position is shown. In this position, the lower portion of the lower valve shoulder 92 aligns with the inner groove 68 of the valve sleeve 20, causing the gap 200 to open to form a bypass fluid path. The bypass fluid path connects the internal fluid of the flow rate control system 10 to the annular space 192 surrounding the housing 14 (e.g., Figure 10 (As shown). The bypass fluid path includes a valve bypass port 84, an internal bypass chamber 110, multiple valve sleeve bypass openings 58, an external bypass chamber 66, and one or more housing bypass openings 41.

[0088] With the flow control system 10 in the partially open position, a portion of the fluid flowing through the upper annulus 26 is diverted via a bypass fluid path and enters the annular space 192. The diverted fluid helps to remove drill cuttings from the borehole annular space 192. In addition, the diverted fluid flow reduces the flow velocity of the fluid flowing to the drilling motor 182, thereby preventing damage to the drilling motor 182 that could be caused by high flow velocities.

[0089] In the partially open position, a bypass fluid path is created, which may include a valve bypass orifice 84, an internal bypass chamber 110, a valve sleeve bypass opening 58, an external bypass chamber 66, and a housing bypass opening 41. When the flow rate control system 10's inner bore and annular space 192 (e.g.) Figure 10When the pressure difference between the two sides of the bypass orifice 84 forces fluid through the bypass fluid path, the second active valve region D is generated by the pressure difference across the bypass orifice 84. The second active valve region D (as shown) Figure 8 The valve assembly 19 (shown) may include a peripheral upper surface 79 (i.e., the portion of the upper surface 72 of valve 30 outside the sealing diameter A and inside the enlarged diameter B). More specifically, the second active valve region D is defined as the cross-sectional area inside the enlarged diameter B of valve assembly 19 minus the first active valve region C. In the partially open position, the second active valve region D can act as a downwardly biased piston that moves in response to the pressure difference between the orifice of the flow control system 10 and the annular space 192. When the gap 200 is open, the flow velocity through the valve orifice 98 decreases because a portion of the fluid flows through the bypass fluid path to the annular space 192. Because the second active valve region D is pressure-biased downward, the total downward force acting on valve 30 against the upward spring force can be equal to or greater than the downward force previously applied solely by the flow velocity when the bypass fluid path is open. Therefore, even when the fluid flow velocity through the valve orifice 98 and the resulting pressure difference decrease when the bypass fluid path is open, valve assembly 19 will not move upward to the closed position.

[0090] Due to the pressure drop across the bottom hole assembly, including the drilling motor 182 and the drill bit 184, the pressure in the annular space 192 is lower than the pressure in the bore of the flow rate control system 10. In the partially open position, the pressure in the portion of the bore 60 of the valve sleeve 20 above the upper surface 72 of the valve 30 is greater than the pressure in the internal bypass chamber 110 (i.e., the pressure below the valve ring 76), which is fluidly connected to the annular space 192. Therefore, the flow rate control system 10 is pressure-controlled in the partially open position. "Pressure control" refers to the upward or downward change in the pressure difference between the fluid pressure in the bore of the flow rate control system and the pressure in the annular space surrounding the flow rate control system, which causes the valve assembly 19 to slide from the partially open position to the fully open position or from the partially open position to the closed position (and from the fully open position to the partially open position, as described below). In other words, when partially open or fully open, the flow rate control system 10 is controlled by the pressure difference between the pressure in the bore of the flow rate control system 10 and the pressure in the annular space 192. If fluid flow slows down or temporarily stops, while the pressure difference between the flow rate control system 10 and the annular space 192 remains constant, the valve assembly 19 will not return to the closed position even if fluid flow decreases or temporarily disappears. When fluid flow stops for an extended period, internal fluid pressure can be released through the bypass fluid path until the force acting on the second active valve region D is less than the upward force from the spring 36 that causes the valve to close.

[0091] When the flow control system 10 is in the partially open position, the pressure difference between the inner bore of the upper ring 26 and the annular space 192 acts on the second active valve region D, causing the valve assembly 19 to slide further downward. As the valve assembly 19 slides further downward, more fluid in the lower damping chamber 162 returns to the inner bore 118 of the spring spindle 34 through the lower nozzle 130, and more fluid enters the upper damping chamber 160 through the upper nozzle 128. The restricted diameters of the nozzles 128 and 130 delay the movement of the valve assembly 19 in response to changes in the pressure difference. The damping chambers 160 and 162 provide a damping effect so that the valve assembly 19 slides in response to an average pressure value over time rather than short-duration changes or faster fluctuations. As the valve 30 and spring spindle 34 slide further downward from the partially open position, more fluid in the valve chamber 138 must also return to the inner bore 118 of the spring spindle 34.

[0092] The increased pressure difference between the inner bore of the upper ring 26 and the annular space 192 causes the valve assembly 19 to continue sliding downwards until it reaches the point where... Figure 13 and Figure 14 The fully open position is shown. In this position, the lower end 74 of valve 30 engages valve stop 22. The lower portion of the lower valve shoulder 92 is positioned below the inner recess 68 of valve sleeve 20 to fully open the bypass fluid path from valve bypass port 84 and internal bypass chamber 110 to multiple valve sleeve bypass openings 58, external bypass chamber 66, and one or more housing bypass openings 41. In the fully open position, maximum bypass flow rate can be achieved via flow rate control system 10. A significant portion of the fluid flowing through upper ring 26 is diverted through the bypass fluid path and enters annular space 192.

[0093] The flow rate control system 10 is pressure-controlled in the fully open position. If fluid flow slows down or temporarily stops (e.g., due to a clogged drill bit or a stalled motor), and the pressure difference between the flow rate control system 10 and the annular space 192 remains constant, the valve assembly 19 will not slide upward toward the closed position. To allow the valve assembly 19 to slide upward and return to the closed position... Figure 1 and Figure 2 The closed position shown requires reducing the pressure difference between the inner bore of the flow control system 10 and the annular space 192. This can be achieved by reducing the pressure in the inner bore of the upper ring 26, increasing the pressure in the annular space 192, or by shutting down the fluid pump and allowing pressure equalization at both ends of the bypass fluid path. The flow control system 10 reaches the partially open position when the pressure difference decreases as intended. Once the valve assembly 19 slides upward beyond the partially open position, the second active valve region D becomes inactive, causing the flow control system 10 to return to a flow control valve. Without sufficient flow rate, the valve assembly 19 continues to move... Figure 1 and Figure 2 The indicated closing position.

[0094] Because the flow rate control system 10 is flow rate controlled in the closed position, it is automatically activated when the fluid flow rate exceeds the maximum allowable flow rate of the drilling motor 182. The flow rate control system 10 is pressure controlled in the partially open and fully open positions. Therefore, after a portion of the fluid flow begins to be transferred to the annular space 192, the flow rate control system 10 will not be accidentally shut down due to flow rate changes. The flow rate control system 10 changes to the closed position only in response to a predetermined pressure change generated at the surface 188. Additionally, the damping effect provided by the arrangement of nozzles 128, 130 and damping chambers 160, 162 prevents the flow rate control system 10 from being accidentally opened or closed due to pressure pulses, vibrations, drill bit blockage, or motor stall. In one embodiment, the damping effect can effectively require the flow rate or pressure change to be maintained for 30-45 seconds before the flow rate control system 10 changes position (i.e., between the closed and partially open positions, or between the partially open and fully open positions).

[0095] The flow rate control system 10 is configured to reach a partially open position at a predetermined flow rate (in Figure 11 and Figure 12 (as shown in the diagram), and reaches the fully open position under a predetermined pressure difference (in Figure 13 and Figure 14 (As shown in the diagram). In this way, the flow rate control system 10 maintains the flow rate to the drilling motor 182 below the maximum desired flow rate. In another embodiment, the predetermined flow rate and predetermined pressure difference can be adjusted, for example, by replacing the orifice ring 32 with an orifice ring of a different inner diameter or by replacing the spring 36 with a spring of a different compression strength. Additionally, the amount of fluid flowing through the bypass fluid path in the partially open and fully open positions can be adjusted by regulating the ratio of the total cross-sectional area of ​​the valve bypass orifice 84 to the total cross-sectional area of ​​the upper surface 72 of the valve 30.

[0096] In an alternative embodiment, the upper damping chamber 160 and the lower damping chamber 162 may be pre-filled with fluid (such as oil or drilling fluid).

[0097] In another alternative embodiment, the upper nozzle 128 and the lower nozzle 130 may be replaced by one or more nozzles extending axially through the sealing block 120 to fluidly connect the upper damping chamber 160 and the lower damping chamber 162. In this embodiment, when the valve assembly 19 travels in the downward direction, fluid flows directly from the lower damping chamber 162 through the nozzle and into the upper damping chamber 160. Conversely, when the valve assembly 19 travels in the upward direction, fluid flows directly from the upper damping chamber 160 through the nozzle and into the lower damping chamber 162. The nozzles and damping chambers provide a damping effect to slow the movement of the valve assembly 19 between the closed position, the partially open position, and the fully open position.

[0098] In another alternative embodiment, the flow control system 10 may include only a damping chamber. In this embodiment, the seal may be omitted to allow fluid flow into the space on the opposite side of the seal block 120.

[0099] In another alternative embodiment, the valve bypass port 84 may extend radially from the inner bore 98 of the valve 30 through to the lower collar surface 78, the reduced diameter section 90, or the lower valve shoulder 92 of the valve 30.

[0100] In yet another alternative embodiment, one or more parts of the valve assembly may be integrally formed or may be divided into separate parts. In one example, the orifice ring and the spring mandrel may be integrally formed from a single piece. In another example, the valve, orifice ring, and spring mandrel may be integrally formed from a single piece. In another example, the spring mandrel may be formed from two or more separate pieces fixed together. In another example, the valve may be formed from two or more separate pieces fixed together. Additionally, one or more parts of the sleeve assembly may be integrally formed or may be divided into separate parts. In one example, the valve stop and the spring sleeve may be integrally formed from a single piece. In another example, the valve sleeve, valve stop, and spring sleeve may be integrally formed from a single piece. In another example, the spring sleeve may be formed from two or more separate pieces fixed together. In another example, the valve sleeve may be formed from two or more separate pieces fixed together.

[0101] In another alternative embodiment, the flow control system may include a valve assembly without a sleeve assembly, such that the valve assembly slides directly within the housing bore.

[0102] In another alternative embodiment, the flow rate control system may include a valve assembly that completely shuts off the flow of drilling fluid through the mud motor below, thereby bypassing all drilling fluid to an annular space outside the housing of the flow rate control system. In this fully bypassed position, the drilling fluid can be replaced with a different fluid (such as LCM fluid, perforation fluid, or fracturing fluid).

[0103] When the flow rate in the flow rate control system 10 exceeds the maximum permissible flow rate, the flow rate control system 10 prevents the drilling motor 182 from being exposed to a fluid flow rate higher than the maximum permissible flow rate by providing bypass flow through a bypass fluid path. For example, but not limited to, if the rated maximum drilling fluid flow rate of the drilling motor is 600 GPM, then when the drilling fluid flow rate in the flow rate control system 10 reaches 900 GPM, the flow rate control system 10 can divert 300 GPM through the bypass fluid path. In another example, but not as a limitation, if the maximum design flow rate of the drilling motor is 600 GPM, then when the drilling fluid flow rate in the flow rate control system 10 reaches 700 GPM, the flow rate control system 10 can divert 100 GPM through the bypass fluid path.

[0104] Unless otherwise described or specified, each component in the device has a generally cylindrical shape and can be formed of steel, another metal, or any other durable material. Parts of the flow control system 10 can be formed of a wear-resistant material such as tungsten carbide or ceramic-coated steel. In one embodiment, valve 30 and valve sleeve 20 are at interface 108 (e.g., ...). Figure 2 The portion shown can be formed of wear-resistant material.

[0105] Each device described in this disclosure may include any combination of the components, features, and / or functions described in each of the various device embodiments. Each method described in this disclosure may include any combination of the described steps in any order, including steps not described, and combinations of steps used in individual embodiments. Any numerical range disclosed herein includes any subrange thereof. “plurality” means two or more. “above” and “below” should be understood to mean upstream and downstream, respectively, such that the directional orientation of the device is not limited to a vertical arrangement.

[0106] While preferred embodiments have been described, it should be understood that these embodiments are merely illustrative, and the scope of the invention is defined only by the appended claims. When the appended claims are satisfied, a full range of equivalents, numerous variations and modifications will naturally occur to those skilled in the art upon review of the invention.

Claims

1. A flow rate control system, comprising: A housing, the housing including one or more housing bypass openings extending radially from an inner housing bore to an outer surface of the housing; A valve assembly slidably disposed within a housing bore, the valve assembly including a valve and an orifice; wherein the valve includes a valve collar defining an upper surface of the valve and defining an outer collar surface and a lower collar surface, a lower valve shoulder, a diameter-decreasing outer surface extending from the lower collar surface to the lower valve shoulder, a valve bore extending axially from the upper surface to a lower end, and a plurality of valve bypass holes extending axially through the valve collar between the valve bore and the outer collar surface; wherein the orifice is disposed within the valve bore; and wherein the valve assembly is configured to slide between a closed position and a fully open position; A spring disposed in the housing bore and surrounding a portion of the valve assembly, wherein the spring biases the valve assembly toward the closed position; In the closed position, the valve closes the housing bypass opening, and in the closed position, the valve assembly is subject to flow rate control. In the partially open position and the fully open position, the bypass fluid path is formed by the valve bypass orifice and the housing bypass opening; and in the partially open position and the fully open position, the valve assembly is pressure controlled.

2. The flow rate control system of claim 1, wherein each of the valve bypass orifices extends from an inlet on the upper surface of the valve to an outlet on the lower collar surface.

3. The flow rate control system according to claim 1, wherein, The orifice is formed by an orifice ring disposed in the inner bore of the valve.

4. The flow rate control system according to claim 1 further includes a sleeve assembly statically fixed in the inner bore of the housing; wherein, The valve assembly is slidably disposed through the sleeve assembly; wherein the sleeve assembly includes a valve sleeve disposed around the valve, the valve sleeve including a reduced diameter section and a plurality of valve sleeve bypass openings extending radially from an inner bore to an outer surface of the reduced diameter section, wherein the bypass fluid path in the fully open position further includes the valve sleeve bypass openings.

5. The flow rate control system of claim 4, further comprising one or more damping chambers formed between the valve assembly and the sleeve assembly, wherein, One or more damping nozzles fluidly connect the inner bore of the valve assembly to the one or more damping chambers to slow down the sliding movement of the valve assembly within the sleeve assembly.

6. The flow rate control system according to claim 4, wherein, A metal-to-metal seal is formed between the valve sleeve and the valve.

7. The flow rate control system according to claim 4, wherein, The bypass fluid path in the partially open position and the fully open position further includes an internal bypass chamber defined between the valve sleeve and the reduced-diameter outer surface of the valve, wherein, in the partially open position and the fully open position, the internal bypass chamber is fluidly connected to the valve bypass orifice and the valve sleeve bypass opening.

8. The flow rate control system according to claim 7, wherein, The bypass fluid path in the partially open position and the fully open position further includes an external bypass chamber defined between the reduced-diameter section of the housing and the valve sleeve, wherein, in the partially open position and the fully open position, the external bypass chamber is fluidly connected to the valve sleeve bypass opening and the housing bypass opening.

9. The flow rate control system according to claim 8, wherein, The valve assembly further includes a spring spindle disposed below the valve and the orifice, the spring spindle including an inner bore and an upper end engaging the inner bore of the valve, wherein the spring is disposed around the outer surface of the spring spindle, and wherein the spring biases the spring spindle toward the closed position to bias the valve toward the closed position.

10. The flow rate control system according to claim 9, wherein, The spring spindle includes a sealing block having an outer surface with an enlarged diameter, wherein the spring biases the sealing block toward the closed position.

11. The flow rate control system according to claim 10 further includes a spring sleeve disposed in the inner hole of the housing and surrounding the spring spindle and the spring.

12. The flow rate control system according to claim 11, wherein, The sealing block defines an upper damping chamber and a lower damping chamber between the spring mandrel and the spring sleeve, the sealing block including at least one upper nozzle for fluidly connecting the inner bore of the spring mandrel to the upper damping chamber and at least one lower nozzle for fluidly connecting the inner bore of the spring mandrel to the lower damping chamber.

13. The flow rate control system according to claim 12 further includes an upper spring ring and a lower spring ring, each of the upper spring ring and the lower spring ring being disposed around the outer surface of the spring spindle, wherein, The upper spring ring is disposed between the sealing block of the spring spindle and the upper end of the spring, wherein the lower spring ring is disposed between the lower end of the spring and the lower shoulder of the spring sleeve.

14. The flow rate control system according to claim 13, wherein, The upper spring ring and the spring are disposed in the lower damping chamber, wherein an annular space is formed between the upper spring ring and the spring sleeve.

15. A method for controlling the flow rate of fluid to a drilling motor, comprising the following steps: a) Providing a flow rate control system, the flow rate control system comprising: a housing including one or more housing bypass openings extending radially from an inner bore of the housing to an outer surface of the housing; a valve assembly slidably disposed within the inner bore of the housing, the valve assembly including a valve and orifices; wherein the valve includes a valve collar defining an upper surface of the valve and defining an outer collar surface and a lower collar surface, a lower valve shoulder, a diameter-decreasing outer surface extending from the lower collar surface to the lower valve shoulder, a valve inner bore extending axially from the upper surface to a lower end, and a plurality of valve bypass orifices extending axially through the valve collar between the valve inner bore and the outer collar surface; wherein the An orifice is disposed within the valve bore; and wherein the valve assembly is configured to slide between a closed position and a fully open position; a spring is disposed within the housing bore and surrounds a portion of the valve assembly, wherein the spring biases the valve assembly toward the closed position; wherein, in the closed position, the valve closes the housing bypass opening, and wherein, in the closed position, the valve assembly is subject to flow rate control; wherein, in the partially open position and the fully open position, a bypass fluid path is formed by the valve bypass orifice and the housing bypass opening; and wherein, in the partially open position and the fully open position, the valve assembly is subject to pressure control; b) Attach the flow rate control system to the tubing above the drilling motor; c) With the valve assembly in the closed position, pump fluid through the flow rate control system so that substantially all of the fluid flows through the valve bore to the drilling motor; d) Increase the flow rate of the fluid above a threshold flow rate value so that the valve assembly slides in the downward direction to the partially open position, in which a portion of the fluid flows through the bypass fluid path into the annular space surrounding the housing.

16. The method of claim 15, further comprising the step of: e) When the flow rate control system is in the partially open position, the flow rate of the fluid passing through the flow rate control system is reduced to below a threshold flow rate value without sliding the valve assembly to the closed position.

17. The method of claim 15, further comprising the step of: e) Maintain or increase the pressure difference between the fluid flowing into the flow rate control system and the fluid in the annular space, so that the valve assembly slides further in the downward direction to the fully open position, thereby increasing the volume of the fluid flowing through the bypass fluid path into the annular space.

18. The method of claim 17, further comprising the step of: f) Reduce the pressure difference between the fluid flowing into the flow rate control system and the fluid in the annular space, so that the valve assembly slides upward to the partially open position, thereby reducing the volume of the fluid flowing through the bypass fluid path into the portion of the annular space.

19. The method of claim 18, further comprising the step of: g) Further reduce the pressure difference between the fluid flowing into the flow rate control system and the fluid in the annular space, so that the valve assembly slides further in the upward direction to the closed position.

20. The method of claim 15, wherein, The flow rate control system further includes a sleeve assembly that is stationarily fixed in the inner bore of the housing, the valve assembly being slidably disposed through the sleeve assembly, wherein the flow rate control system further includes one or more damping chambers formed between the valve assembly and the sleeve assembly, wherein the one or more damping chambers are fluidly connected to the inner bore of the valve assembly through one or more nozzles; and wherein, in step (d), the one or more damping chambers slow down the sliding movement of the valve assembly.

21. The method of claim 15, further comprising the step of: e) The flow rate control system is placed in a fully bypassed position, in which all fluid flowing into the flow rate control system is transferred through the bypass fluid path to the annular space surrounding the housing above the drilling motor.

22. The method according to claim 21, wherein, The fluid flowing into the flow rate control system at the fully bypassed position is an LCM-rich drilling fluid, perforation fluid, or fracturing fluid.

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