Downhole separation system and method

Abstract

A downhole separation system for use upstream of any tool through which a medium flows. The separation system filters at least a portion of any solids from the medium flowing through a filtered flow path. The separation system flushes at least a portion of the filtered solids through a flushing flow path, through a flushing outlet on an outer surface of the housing, and into a space surrounding the housing. A screen and an activation mechanism are disposed within a bore of the housing. The filtered flow path extends through a plurality of openings in the screen. The activation mechanism is configured to move between a default position in which the activation mechanism directs fluid through the filtered flow path and an activated position in which the activation mechanism directs fluid through the flushing flow path. Optionally, a spring within the bore of the housing is configured to bias the activation mechanism toward the default position.

Description

background

[0001] During drilling and well maintenance, drilling fluid is pumped by drilling motors (such as positive displacement motors) and other drilling and completion equipment (such as friction-reducing tools, impact hammers, and turbines). Most drilling fluids contain solid particles (e.g., weighting materials such as barite and hematite; low-gravity solids such as bentonite, broken rock, and drill cuttings). Certain parts of drilling and completion equipment are sensitive to solid particles in the drilling fluid. For example, some drilling motors consist only of metal parts that do not flex when drilling fluid containing solid particles flows between them. Instead, solid particles often wed between two metal parts, causing premature wear or cessation of rotation of the drilling motor, resulting in metal-to-metal drilling motor failure. The power section of a standard drilling motor includes a nitrile elastomer material that flexes to allow solid particles to flow through the motor. However, these elastomer materials may begin to degrade or fail when the drilling motor is exposed to the high temperatures inside the wellbore or to oil-based drilling fluids with low aniline points.

[0002] In both cases, the filter is sometimes located upstream of the drilling motor to reduce the amount of solid particles in the drilling fluid before it enters the motor. However, the filter has a limited capacity to collect solid particles and fills up after a period of time. Once the filter reaches its capacity, some conventional filters guide the drilling fluid through a path within the filter, bypassing the solid particle trapping section, thus retaining any solid particles it contains while allowing unfiltered drilling fluid to reach the downstream drilling motor.

[0003] Figure 1 and Figure 2 An example of a conventional filter 2 is shown. Fluid flowing through filter 2 is directed across filter surface 4 to collect solid particles within filter sleeve 6. When a predetermined amount of solid particles is retained within filter sleeve 6, the associated pressure drop causes shear pin 8 to break and release filter sleeve 6, which then moves downstream to open bypass port 10, as... Figure 2 As shown. In this position, when the filter sleeve 6 is filled with solid particles, fluid is allowed to continue flowing through the filter 2. However, the fluid flowing through the bypass port 10 is unfiltered, which increases the possibility that solid particles may damage the downstream drilling motor.

[0004] To remove collected solid particles from the filter, a conventional filter is typically pulled out of the drill string for cleaning. For example, it may be necessary to... Figure 1 and Figure 2Filter 2 is pulled out of the drill string to remove collected solid particles before the fluid can be filtered again. Removing the filter from the wellbore requires the user to stop drilling operations, resulting in wasted drilling time and increased drilling costs. Alternatively, the collected solid particles can be removed from the filter by opening the solid particle collection section of the filter to flush the collected solid particles downstream through the central fluid path to the drilling motor with the flow of drilling fluid. Flushing the collected solid particles downstream with drilling fluid increases the amount of solid particles flowing through the drilling motor, which increases the likelihood that solid particles will wed between the two metal parts in the metal-to-metal drilling motor, thereby increasing the possibility that some drilling motors will wear out prematurely or stop working completely.

[0005] There is a need for a downhole separation system that filters solid particles from drilling fluids and removes collected solid particles from a filter without removing the system or filter from the wellbore or releasing the collected solid particles downstream. Brief description of the attached diagram

[0006] Figure 1 This is a cross-sectional view of a prior art filter device in the filtration position.

[0007] Figure 2 It is in a bypass position. Figure 1 The diagram shows a cross-sectional view of a prior art filter device.

[0008] Figure 3 This is a front view of the separated system of this disclosure in its default position.

[0009] Figure 4 This is a detailed cross-sectional view of a part of the separation system in its default position.

[0010] Figure 5 This is another detailed cross-sectional view of a part of the separation system in its default position.

[0011] Figure 6 This is another detailed cross-sectional view of a part of the separation system in its default position.

[0012] Figure 7 This is a front view of the outer valve sleeve of the separation system.

[0013] Figure 8 This is a perspective view of the outer valve sleeve.

[0014] Figure 9 This is a front view of the mandrel of the separation system.

[0015] Figure 10 This is a perspective view of the mandrel.

[0016] Figure 11This is a cross-sectional view of the inner valve sleeve of the separation system.

[0017] Figure 12 This is a front view of the piston in the separation system.

[0018] Figure 13 This is a cross-sectional view of the separation device in a partially activated position.

[0019] Figure 14 This is a detailed cross-sectional view of a part of the separation system in a partially activated position.

[0020] Figure 15 This is another detailed cross-sectional view of a part of the separation system in a partially activated position.

[0021] Figure 16 This is another detailed cross-sectional view of a part of the separation system in a partially activated position.

[0022] Figure 17 This is a cross-sectional view of the separation device in the active position.

[0023] Figure 18 This is a detailed cross-sectional view of a part of the separation system in the active position.

[0024] Figure 19 This is another detailed cross-sectional view of a part of the separation system in the active position.

[0025] Figure 20 This is another detailed cross-sectional view of a part of the separation system in the active position.

[0026] Figure 21 This is a schematic diagram of an embodiment of a downhole separation system positioned in an underground wellbore via a coiled tubing string.

[0027] Figure 22 This is a schematic diagram of an embodiment of a downhole separation system positioned in an underground wellbore via a tubing string.

[0028] Figure 23 This is a schematic diagram of the upstream and downstream separation systems located within the same tubing string in an underground well.

[0029] Detailed description of the selected embodiment

[0030] This paper discloses a separation system that automatically or in response to a signal from the wellbore surface flushes collected solids into an annular space around the outer surface of the wellbore. Figures 3 to 23 Embodiments of the separation system disclosed herein are shown, wherein many other embodiments within the scope of the claims will be readily apparent to those skilled in the art upon review of this disclosure.

[0031] Figure 3 An embodiment of a downhole separation system in its default filtration position is shown. The downhole separation system 20 may include a housing 22, which may include two or more segments, such as housing segments 22a, 22b, and 22c. Each housing segment 22a, 22b, and 22c may have a generally cylindrical shape and a housing bore 24 extending therethrough. The upper and lower ends of the housing 22 may be configured to connect to tubular members in a drill string. The housing 22 may include one or more flushing outlets 26 extending radially from the housing bore 24 to an outer surface 28 of the housing 22.

[0032] The screen 30 and the sliding assembly 32 can be fixed within the inner hole 24 of the housing. The sliding assembly 32 can be configured to slide within the inner hole 24 of the housing. A portion of the sliding assembly 32 can be configured to slide within the central hole of the screen 30. The sliding assembly is configured to be in its default position within the inner hole 24 of the housing. Figure 3 (as shown) and activation location ( Figure 17 Sliding between (shown in the diagram). In the default position, the filter flow path is open and the flush outlet 26 is closed. The filter flow path extends through the opening in the screen 30. In the active position, the flush flow path leading to the flush outlet 26 is open. In some embodiments, the filter flow path is partially or completely closed in the active position. In this way, the sliding assembly 32 is the activation mechanism of the downhole separation system 20.

[0033] In the illustrated embodiment, the sliding assembly 32 may include a spindle 36, an inner valve sleeve 38, and a piston 40. A spring 42 disposed within the housing bore 24 may bias the sliding assembly 32 toward a default position, which in the illustrated embodiment is upstream. The spring 42 may be disposed around a portion of the piston 40, which may slide within a central region of the spring 42 when the piston 40 compresses the spring 42. A first diverter 44 and a second diverter 46 may secure the screen 30 within the housing bore 24. The spindle 36 may be configured to slide through a central bore in the first diverter 44 and the second diverter 46. An outer valve sleeve 48 may also be secured within the housing bore 24. The inner valve sleeve 38 is slidably disposed within the outer valve sleeve 48. In some embodiments, the outer valve sleeve 48 defines upstream and downstream limits of the sliding path of the inner valve sleeve 38. In some embodiments, the outer valve sleeve 48 is aligned with a flush outlet 26 of the housing 22. The outer valve sleeve 48 may include one or more sleeve ports 50.

[0034] refer to Figures 3 to 5The first diverter 44 may include a central aperture 62, a plurality of first diverter channels 64, and a screen receiving portion 66. The plurality of first diverter channels 64 extend in an axial direction and are positioned between the central aperture 62 and the outer surface of the first diverter 44. The central aperture 62 of the first diverter 44 may include a shoulder 68, which provides a larger diameter central aperture upstream of the shoulder 68 and a smaller diameter central aperture downstream of the shoulder 68. Similarly, the second diverter 46 may include a central aperture 70, a plurality of second diverter channels 72, and a screen receiving portion 74. The plurality of second diverter channels 72 extend in an axial direction and are positioned between the central aperture 70 and the outer surface of the second diverter 46. The central aperture 70 of the second diverter 46 may include a shoulder 76, which provides a smaller diameter central aperture upstream of the shoulder 76 and a larger diameter central aperture downstream of the shoulder 68. The screen 30 may include a plurality of openings 78 extending radially from the central aperture 80 to the outer surface 82. The screen 30 is configured to filter any solids contained in a medium (e.g., a liquid or gas, which may be drilling media) flowing through multiple openings 78. The upstream end 84 of the screen 30 may be fixed within the screen receiving portion 66 of the first diverter 44, and the downstream end 86 of the screen 30 may be fixed within the screen receiving portion 74 of the second diverter 46.

[0035] In some embodiments, a screen assembly formed by a screen 30 between the first diverter 44 and the second diverter 46 can be fixed in a static configuration within the housing bore 24. For example, in the illustrated embodiment, the screen assembly is fixed within the housing section 22b by means of a shoulder 88 of the housing section 22b and the lower end of the housing section 22a. More specifically, in the illustrated embodiment, the downstream surface of the second diverter 46 engages the shoulder 88 of the housing section 22b without obstructing the second diverter channel 72, and the upstream surface of the first diverter 44 engages the lower end of the housing section 22a without obstructing the first diverter channel 64.

[0036] refer to Figure 3 and Figures 6 to 8The outer valve sleeve 48 may include a central bore 89 configured to allow the inner valve sleeve 38 to slide therein. The outer valve sleeve 48 may be fixed in a static configuration within the housing bore 24. For example, in the illustrated embodiment, the upstream end 90 of the outer valve sleeve 48 engages a spacer 92, which engages the lower end of the housing segment 22b, and the downstream end 94 of the outer valve sleeve 48 engages a valve stop 96, which engages a shoulder 98 of the housing segment 22c. The valve stop 96 may include a recess for receiving a sealing member 99, which may provide a sliding fluid seal between the valve stop 96 and the piston 40. The housing 22 and the outer valve sleeve 48 may be configured to provide a flushing outlet 100 between the outer valve sleeve 48 and the housing 22. The flushing outlet 100 may be in fluid communication with the sleeve port 50 of the outer valve sleeve 48 and the flushing outlet 26 of the housing 22. In some embodiments, such as the illustrated embodiment, the flushing outlet 100 may be defined by a recess 101 in the outer surface of the outer valve sleeve 48 and a recess in the housing bore 24. Alternatively, the flushing outlet 100 may be defined only by a recess in the outer surface of the outer valve sleeve 48 or only by a recess in the housing bore 24. In some embodiments, the sleeve port 50 of the outer valve sleeve 48 may be offset from the flushing outlet 26 of the housing 22. This offset arrangement can reduce wear by reducing the rate at which fluid or other media flows through the flushing outlet 26 and the sleeve port 50. In other embodiments, the sleeve port 50 may be aligned with the flushing outlet 26. The outer valve sleeve 48 may also include one or more recesses 102 for receiving a sealing member 104, which may provide a fluid seal between the outer surface of the outer valve sleeve 48 and the housing bore 24.

[0037] Now for reference Figures 3 to 6 and Figures 9 to 10 The mandrel 36 may include a main collar 110, a secondary collar 112 extending from shoulder 113 to shoulder 114, and an outer surface 115 extending from shoulder 114 to downstream end 116. The mandrel 36 may also include an upstream center bore 118 and a downstream center bore 120 separated by a mandrel core 122. One or more mandrel filter ports 124 may extend radially from the upstream center bore 118 to the outer surface of the secondary collar 112. One or more mandrel flush ports 126 may extend radially from the upstream center bore 118 to the outer surface 115. The upstream center bore 118 may include a tapered surface 127 between the mandrel filter ports 124 and the mandrel flush ports 126. One or more lower mandrel ports 128 may extend radially from the downstream center bore 120 to the outer surface 115.

[0038] refer to Figure 4 and Figure 5The outer surface of the main shaft ring 110 of the mandrel 36 can engage with the inner hole 24 of the housing. A portion of the mandrel 36 can slide within the central hole 62 of the first distributor 44, the central hole 80 of the screen 30, and the central hole 70 of the second distributor 46. Figures 3 to 6 In the default position shown, the mandrel 36 can be positioned such that the mandrel filter port 124 is open to the filter port cavity 130, which is defined by the housing bore 24, the shoulder 113 of the mandrel 36, and the upper surface of the first diverter 44. In this position, the mandrel flushing port 126 can be positioned within the smaller diameter region of the central bore 62 of the first diverter 44. Also in this position, the lower mandrel port 128 can open to the screen cavity 132, which is defined between the central bore 80 of the screen 30 and the outer surface 115 of the mandrel 36, and between the first diverter 44 and the second diverter 46. Therefore, in the default position, the mandrel filter port 124 and the lower mandrel port 128 are open, while the mandrel flushing port 126 is closed. The mandrel cavity 134 can extend from the shoulder 114 of the mandrel 36 to the shoulder 68 of the first diverter 44 between the central bore 62 of the first diverter 44 and the outer surface 115 of the mandrel 36. The collection chamber 136 can extend from the first diverter 44 to the second diverter 46 between the inner hole 24 of the housing and the outer surface 82 of the screen 30.

[0039] Now for reference Figure 6 and Figure 11 The inner valve sleeve 38 is slidably disposed within the central hole 89 of the outer valve sleeve 48. Figure 6 In the default position shown, the upstream end of the inner valve sleeve 38 may engage the lower end of the spacer 92. The central bore of the inner valve sleeve 38 may include an upstream bore 140 extending from the upstream end of the inner valve sleeve 38 to the shoulder 142 and a downstream bore 144 extending from the shoulder 146 to the downstream end of the inner valve sleeve 38. A protrusion 148 may be formed between the shoulders 142 and 146. The central bore of the inner valve sleeve 38 may also include a diameter enlargement region 150 near its downstream end. The downstream end 116 of the mandrel 36 is positioned within the upstream bore 140 of the inner valve sleeve 38, engaging the shoulder 142. The upstream end of the piston 40 is positioned within the downstream bore 144 of the inner valve sleeve 38. In some embodiments, a ring 151 may also be provided between the upstream end of the piston 40 and the shoulder 146. In other embodiments, the upstream end of the piston 40 engages the shoulder 146. The inner valve sleeve 38 may also include one or more recesses 152 in the upstream bore 140, the downstream bore 144, and on the outer surface of the inner valve sleeve 38 for receiving a sealing member 153. Sealing member 153a may provide a fluid seal between the upstream bore 140 and the outer surface of the spindle 36. Sealing member 153b may provide a fluid seal between the downstream bore 144 and the outer surface of the piston 40. Sealing member 153c may provide a fluid seal between the outer surface of the inner valve sleeve 38 and the outer valve sleeve 48.

[0040] refer to Figure 3 , Figure 6 and Figure 12 The piston 40 may include a central bore 154, an upstream outer surface 156 extending from an upstream end to a shoulder 158, and a downstream outer surface 160 extending from a shoulder 162 to a downstream end. A sealing block 164 may form a diameter-enlarged region between the shoulders 158 and 162. Figure 6 and Figure 12 As shown, the sealing block 164 may include a recess 166 configured to receive a sealing member 155, which may include an O-ring or other sealing element. A portion of the outer surface of the sealing block 164 may engage the housing bore 24 to provide a fluid seal separating the first damping chamber 167 and the second damping chamber 168 (e.g., Figure 3 (As shown). One or more fluid channels may extend through the body of the sealing block 164 and connect the first damping cavity 167 and the second damping cavity 168 to each other. For example, one or more first nozzles 169 above the sealing recess 166 and one or more second nozzles 170 below the sealing recess 166 may extend inward from the outer surface of the sealing block 164 (as shown). Figure 12 (As shown). In some embodiments, each first nozzle 169 is fluidly connected to one of the second nozzles 170, such that a nozzle path is formed from the first damping cavity 167 through the sealing block 164 to the second damping cavity 168. The nozzle path may include a flow path diameter limitation. In other embodiments, the fluid passage connecting the first damping cavity 167 and the second damping cavity 168 may include an annular space between the sealing block 164 and the housing bore 24.

[0041] The piston 40 may also include an orifice 172 extending from the central bore 154 to the upstream outer surface 156. The position of the piston 40 within the downstream bore 144 of the inner valve sleeve 38 allows the orifice 172 to be aligned with the diameter enlargement 150 of the inner valve sleeve 38. Figure 6 In the default position shown, valve chamber 174 extends from the downstream end of inner valve sleeve 38 to valve stop 96, which is located between the central bore 89 of outer valve sleeve 48 and the upstream outer surface 156 of piston 40. Valve chamber 174 is fluidly connected to the central bore 154 of piston 40 through orifice 172 and enlarged diameter section 150. In the default position, shoulder 158 of piston 40 can engage the lower surface of valve stop 96.

[0042] Refer again Figure 3 and Figure 6Spring 42 can be positioned within spring cavity 176, which is defined between housing bore 24 and downstream outer surface 160 of piston 40. Spring 42 can be positioned between first spring block 180 and second spring block 182. First spring block 180 can be positioned within housing bore 24 between spring 42 and shoulder 162 of piston 40. Flow passage 183 between housing bore 24 and first spring block 180 fluidly connects second damping cavity 168 and spring cavity 176, thereby effectively forming combined downstream damping cavities 168 / 176. Second spring block 182 can be positioned within housing bore 24 between spring 42 and shoulder 184 of housing segment 22c. A portion of piston 40 can be configured to pass through a central bore in spring block 180 and a central bore in spring block 182. Spring 42 can apply a force in the upstream direction to the first spring block 180, which generates an upstream force applied to the shoulder 162 of piston 40, the shoulder 146 of inner valve sleeve 38, and the downstream end 116 of spindle 36. In this way, spring 42 moves the first spring block 180, the seal 164 of piston 40, inner valve sleeve 38, and spindle 36 in the upstream direction towards Figure 3 The default position offset is shown.

[0043] Figures 3 to 6 A downhole separation system 20 in its default position is shown, in which media flowing into the housing bore 24 at the upper end of the housing 22 is directed through a filtration flow path within the housing 22. The filtration flow path extends through multiple openings 78 of a screen 30 to filter at least a portion of any solids from the media. In some embodiments, the filtration flow path extends through a collection chamber 136 before the multiple openings 78 of the screen 30. For example, the filtration flow path may extend from the upper end of the housing bore 24 into an upstream central bore 118, through one or more mandrel filter ports 124, through filter port cavities 130, through multiple first diverter channels 64, through the collection chamber 136, through the multiple openings 78 of the screen 30, through a screen cavity 132, through the lower mandrel port 128 into a downstream central bore 120 of the mandrel 36, and through a central bore 154 of the piston 40. As the medium flows through the filtration flow path, at least a portion of any solids contained in the medium is retained in the collection chamber 136 as the medium passes through the multiple openings 78 of the screen 30. The filtered medium continues to flow through the screen chamber 132, through the remainder of the filtration flow path, and further downstream, while the collected solids remain in the collection chamber 136. In this way, the downhole separation system 20 in its default position filters out at least a portion of any solids contained in the medium flowing through the system, retains the collected solids, and allows the filtered medium to continue flowing downstream.

[0044] In the default position, fluid or other media can be contained in the mandrel cavity 134 between the mandrel 36 and the first distributor 44 (e.g., Figure 4 As shown), contained in valve cavity 174 between outer valve sleeve 48 and piston 40 (as shown). Figure 6 As shown), it is contained in the first damping cavity 167 and the second damping cavity 168 between the inner bore 24 of the housing and the sealing block 164 of the piston 40 (as shown). Figure 6 As shown), and contained in the spring cavity 176 between the housing bore 24 and the piston 40 (as shown). Figure 6 and Figure 3 (As shown). In some embodiments, media may enter some of these cavities during use. For example, a small amount of media flowing through the housing bore 24 may permeate through the connection between the mandrel 36 and the first distributor 44 to enter the mandrel cavity 134. A small amount of media flowing through the central bore 154 of the piston 40 may flow through the orifice 172 and the enlarged diameter region 150 of the inner valve sleeve 38 to enter the valve cavity 174, which may be fluid-sealed upstream by sealing members 153b and 153c and downstream by sealing member 99 and a compression seal formed by the contact between the valve stop 96 and the shoulder 98.

[0045] In some embodiments, certain fluid chambers of the separation system 20 may be filled with a medium before use. For example, damping chambers 167 and 168 / 176 may be filled with fluid during assembly of the separation system 20. The damping chambers may be filled with a fluid having a constant viscosity over a wide temperature range, such as ethylene glycol. In some embodiments, damping chambers 167 and 168 / 176 may be filled during use when a looser seal is used.

[0046] refer to Figure 3 and Figure 6 The damping chambers 167 and 168 / 176, together with the nozzles 169 and 170, can form a damping mechanism for the independent seal of the separation system 20. The independent sealing unit can be provided by an upstream fluid seal and a compression seal formed at the interface between the valve stop 96 and the shoulder 98 by the sealing member 199 (e.g., ...). Figure 3 The downstream fluid seal provided (shown) is formed. Sealing member 199 provides a fluid seal at the sliding interface between the lower outer surface of piston 40 and the housing bore 24 downstream of shoulder 184. In these embodiments, a fixed amount of fluid initially filled into cavities 167, 168, and 176 can be retained in these cavities during use.

[0047] The sealing member 155 fluidly seals the interface between the housing bore 24 and the sealing block 164 of the piston 40. Fluid communication between the first damping chamber 167 and the combined downstream damping chambers 168 / 176 is achieved solely through one or more first nozzles 169 and one or more second nozzles 170 (e.g., ...). Figure 6 and Figure 12 Provided (as shown). The first nozzle 169 and the second nozzle 170 can be configured to control or limit the flow rate of fluid between damping cavities 167 and 168 / 176. As the sliding assembly 32 moves upstream or downstream, the respective volumes of the first damping cavity 167 and the combined downstream damping cavities 168 / 176 change. The axial downstream movement of the piston 40 pushes a volume of fluid from the combined downstream damping cavities 168 / 176 through nozzles 170 and 169 into the first damping cavity 167. The size and number of nozzles 169 and 170 determine the flow rate at which fluid can move between the damping cavities 167 and 168 / 176, which in turn controls and reduces the sliding speed or rate of axial movement or sliding of the sliding assembly 32 (including the piston 40 and the spindle 36) in each direction. In this way, the damping mechanism prevents the instantaneous opening and closing of the bypass port 26. The damping mechanism also prevents breakage of components of the separation system 20 that may be caused by rapid axial movement of the sliding assembly 32. The degree to which the damping mechanism attenuates or slows down the axial movement of the sliding assembly 32 can be adjusted by changing the number and size of the nozzles 169 and 170. In one embodiment, the first nozzle 169 and the second nozzle 170 each include a reduced diameter portion to restrict fluid flow based on the sum of the force from the spring 42 acting on the valve assembly 32 and the pressure difference generated by the fluid flowing through the valve assembly 32.

[0048] refer to Figures 3 to 6 In the default position, the medium flowing through the separation system 20 applies a downstream force to the effective area of ​​the sliding assembly 32, which may include the mandrel effective area on the mandrel 36 and the valve effective area on the inner valve sleeve 38. The mandrel effective area can be determined by the cross-sectional area of ​​the surface provided by the upstream surface 185 of the main shaft ring 110 of the mandrel 36, the tapered surface 127 within the upstream central bore 118, and the end face 186 of the upstream central bore 118 (e.g., ...). Figure 4(As shown). The effective area of ​​the valve can be defined by the cross-sectional area of ​​the portion of the upstream surface 188 of the inner valve sleeve 38 exposed to the pressure and downstream force exerted by the medium flowing through the inner bore 24 of the housing. The sliding assembly 32 is axially movable relative to the outer valve sleeve 48 and the sealing member 99, both of which are fixed relative to the housing 22 at the shoulder 98. In the default position, the cumulative upstream effective area is approximately equal to the cumulative downstream effective area of ​​the sliding assembly 32, making the sliding assembly 32 a balanced (or non-biased) piston assembly. Changes in hydrostatic pressure do not force the sliding assembly 32 to move axially in either direction from the default position. For this reason, the separation system 20 is flow-controlled in the default position. As used herein, “flow-controlled” means that a change in the flow rate of the medium flowing through the separation system 20 causes a pressure differential on the sliding assembly 32, which generates a downstream force acting on the effective area to move the sliding assembly 32 from the default position to a partially activated position.

[0049] The increased flow rate of the medium flowing through the separation system 20 in the default position applies an increased downstream force to the effective area of ​​the sliding assembly 32. When the downward force reaches a threshold force value that overcomes the upstream spring force on the sliding assembly 32, the downstream force causes the sliding assembly 32 to move downstream within the housing bore 24 and compress the spring 42. Specifically, the spindle 36 slides downstream within the first and second distributors 44 and 46, within the screen 30, and within the outer valve sleeve 48; the inner valve sleeve 38 slides downstream within the outer valve sleeve 48; and the piston 40 slides downstream within the outer valve sleeve 48, the valve stop 96, the second spring block 182, and the housing bore 24.

[0050] For the sliding assembly 32 to slide downstream, a portion of the medium contained in certain chambers of the separation system 20 must be discharged from those chambers. For example, for the mandrel 36 to move downstream, a portion of the fluid in the mandrel chamber 134 must return to the housing bore 24 and / or the upstream center bore 118 of the mandrel 36. Similarly, for the inner valve sleeve 38 to slide downstream, a portion of the fluid in the valve chamber 174 will return to the center bore 154 of the piston 40. Furthermore, for the piston 40 to slide downstream, a portion of the fluid in the combined downstream damping chambers 168 / 176 must flow into the first damping chamber 167 through the first nozzle 169 and the second nozzle 170. The restricted diameters of nozzles 169 and 170 delay the movement of the sliding assembly 32 in response to changes in the medium flow rate. Thus, the damping chambers provide damping for the movement of the sliding assembly 32. The sliding assembly 32 slides in response to an average flow rate that varies over time, rather than in response to short-term changes or faster fluctuations.

[0051] Now for reference Figures 13 to 16The sliding assembly 32 slides downstream in response to an increased fluid flow rate until it reaches the partially activated position shown. In some embodiments, fluid in the second damping chamber 168 must flow into the first damping chamber 167 to provide a damping effect so that the sliding assembly 32 slides in response to an average pressure value that changes over time, rather than in response to short-term changes or faster fluctuations. In this position, the lower mandrel port 128 is disposed within the central bore 70 of the second diverter 46, which effectively closes the lower mandrel port 128. Also in this position, the mandrel filter port 124 is partially positioned within the central bore 62 of the first diverter, leaving only a gap 190 of the mandrel filter port 124 leading to the filter port cavity 130; a portion of each mandrel filter port 126 leads to the screen cavity 132, forming a gap 192; and the upstream surface 188 of the inner valve sleeve 38 is aligned with the sleeve port 50 of the outer valve sleeve 48 to open the gap 194. In the partially activated position, the flushing flow path is open. The flushing flow path can extend through the screen cavity 132 before the multiple openings 78 of the screen 30 and the collection cavity 136, to flush the collected solids contained in the collection cavity 136 from the separation system 20 through the flushing outlet 26 into the space surrounding the outer surface 28 of the housing 22. For example, the flushing flow path can extend from the upper end of the housing bore 24 to the upstream central bore 118, through the flushing mandrel port 126, through the screen cavity 132, through the multiple openings 78 of the screen 30, through the collection cavity 136, through the multiple second diverter channels 72, through the housing bore 24 below the second diverter 46, through the spacer 92, through the upstream end of the outer valve sleeve 48, through the gap 194, through the sleeve port 50, through the flushing outlet 100, through the flushing outlet 26, and reach the outside of the outer surface 28 of the housing 22. As the medium flows through the flushing flow path, the medium can transport the collected solids held in the collection chamber 136 to the space surrounding the outer surface 28 of the housing 22 through the sleeve port 50 and the flushing outlet 26. In some embodiments, the filter flow path is closed in a partially activated position.

[0052] With the separation system 20 in the partially activated position, the pressure difference between the housing bore 24 and the space surrounding the outer surface 28 of the housing 22 can force the medium flowing through it through a flushing flow path. In this position, the downstream force on the sliding assembly 32 is generated by the pressure difference between the housing bore 24 and the space surrounding the outer surface 28 of the housing 22 at the sleeve port 50 and the flushing outlet 26. Specifically, the effective area in the partially activated position includes the spindle effective area and the valve effective area, which, due to the spacing of the spacer 92, can include the total surface area of ​​the upstream surface 188 of the inner valve sleeve 38. In the partially activated position, the effective area can act as a downstream bias piston, which moves in response to the pressure difference between the housing bore 24 and the annular space surrounding the outer surface 28 of the housing 22. Because the sliding assembly 32 is biased in the downstream direction, if the flow velocity through the housing bore 24 decreases, the total downstream force acting on the sliding assembly 32 against the upstream spring force can be equal to or greater than the previous downstream force applied solely by the flow velocity. For this reason, even if the fluid flow rate decreases, the sliding component 32 will not move to the default position in the upstream direction when the flushing flow path is opened.

[0053] Within the wellbore, due to the pressure drop across the bottomhole assembly, the pressure in the annular space surrounding the housing 22 is lower than the pressure within the housing bore 24. In the partially activated position, the pressure within the housing bore 24 is greater than the pressure in the annular space. Therefore, the separation system 20 is pressure-controlled in the partially activated position. "Pressure control" refers to the upward or downward change in the pressure difference between the fluid pressure in the housing bore 24 of the separation system 20 and the pressure in the annular space surrounding the housing 22, causing the sliding assembly 32 to slide from the partially activated position to the fully activated position or the default position, respectively. In other words, when partially or fully activated, the system 20 is controlled by the pressure difference between the pressure in the housing bore 24 and the annular space surrounding the housing 22. If fluid flow slows down while the pressure difference between the separation system 20 and the annular space remains low, the sliding assembly 32 will not return to the default position even if fluid flow decreases. When fluid flow stops, the internal fluid pressure can be released by flushing the flow path until the force acting on the effective area is less than the upstream force from the spring 42, which biases the sliding assembly 32 in the upstream direction.

[0054] refer to Figures 17 to 20The increased pressure difference between the inner bore 24 of the housing and the annular space surrounding the housing 22 causes the sliding assembly 32 to continue sliding downstream until it reaches the fully activated position shown. In this position, the shoulders 113 and 114 of the mandrel 36 engage the upper end and shoulder 68 of the first diverter 44, respectively. The filter mandrel port 124 can be fully disposed within the central bore of the first diverter 44, and the lower mandrel port 128 can remain fully disposed within the central bore of the second diverter 46 to close the filter mandrel port 124 and hold the lower mandrel port 128 in the closed position. In the fully activated position, the flushing mandrel port 126 can be fully disposed within the sieve chamber 132 to fully open the flushing flow path. In the fully activated position, the medium flowing through the system 20 can flush the collected solids from the collection chamber 136 and discharge them through the sleeve port 50 and the flushing outlet 26.

[0055] The separation system 20 is pressure-controlled in the fully activated position. If fluid flow slows down, and the pressure difference between the housing bore 24 and the annular space decreases slightly, the sliding assembly 32 will not slide upstream toward the default position. To allow the sliding assembly 32 to slide upstream and return to its original position... Figures 3 to 6 The default position shown reduces the pressure difference between the housing bore 24 and the annular space. This can be achieved by reducing the pressure in the housing bore 24, increasing the pressure in the annular space, or by shutting off the fluid pump and allowing the pressure to equalize along the flushing fluid path. Once the sliding assembly 32 has slid past the partially activated position in the upstream direction, the activated area returns to the flow-controlled valve state. Without sufficient flow velocity, the sliding assembly 32 continues to move... Figures 3 to 6 The default location shown.

[0056] Because the separation system 20 is flow rate controlled in its default position, it is automatically activated when the fluid flow rate exceeds a predetermined force threshold. The separation system 20 is pressure-controlled in both the partially activated and fully activated positions. Therefore, after the media and any collected solids are flushed into the annular space, the separation system 20 will not be accidentally shut down due to flow rate changes. The separation system 20 rotates to the default position only in response to a predetermined pressure change generated on the surface of the wellbore. Additionally, the damping effect provided by nozzles 169 and 170 and damping chambers 167 and 168 prevents the separation system 20 from being unintentionally activated or deactivated 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 a specific time (e.g., 30 to 45 seconds) before the separation system 20 changes position.

[0057] The separation system 20 is configured to activate at a predetermined flow rate at a partially activated position (in Figures 13 to 16 (in the middle) and when the predetermined pressure difference reaches the fully activated position (in Figures 17 to 20 (in the middle). In another embodiment, the predetermined flow rate and predetermined pressure difference can be adjusted, for example, by replacing spring 42 with springs of different compressive strengths or different lengths, or by replacing ring 151 with different inner diameters.

[0058] Now for reference Figure 21 Downstream separation system 20 can be secured to coiled tubing connector 200 at the distal end of coiled tubing string 202, which extends below ground level 206 through underground formation 208 for drilling wellbore 204. In some embodiments, MWD tool 210 can be positioned between coiled tubing connector 200 and separation system 20, with drive mechanism 212 (e.g., drilling motor) and drill bit or milling cutter 214 located downstream. Drilling medium can be pumped through coiled tubing string 202 and coiled tubing connector 200. When drilling medium flows through separation system 20 in default position (i.e., filtration mode), all or part of the solid particles in the drilling medium can be removed and collected in collection chamber 136. Filtered or cleaned drilling medium (i.e., the remaining liquid or gaseous components) flows downstream through drive mechanism 212 and drill bit 214. In some embodiments, separation system 22 can be activated in response to an increase in the flow rate of drilling medium. When the separation system 22 reaches a predetermined threshold flow rate, the sliding component 32 of the separation system 22 can be placed in a fully activated or partially activated position. In this partially activated or fully activated position (i.e., flushing mode), the separation system 22 uses the flow of drilling media to flush the collected solid particles out of the separation system through the flushing outlet 26 and into the annular space 216 between the separation system 22 and the formation 208. Once the upstream fluid pressure drops below a predetermined deactivation value, the separation system 20 can automatically move back to the default position, allowing solid particles to be collected again from the drilling media flowing through the separation system 20, and the clean drilling media then flows through the drive mechanism. The separation device 20 can also be placed in a filtering or flushing mode in response to a signal received from the surface 206 of the wellbore 204. Such signals can be, but are not limited to, a sequence of pressure pulses (mud weight changes), flow rate changes, drill pipe rotation changes, or the use of RFID (Radio Frequency Identification) technology.

[0059] refer to Figure 22 The separation system 20 can be attached to the distal end of the drill string 220 used for drilling the wellbore 204. In this embodiment, the MWD tool 210 can be positioned upstream of the separation system 20, with the drive mechanism 212 and drill bit 214 positioned downstream. The drive mechanism 212 may include a curved housing drilling motor. Drilling media flowing through the drill string 220 can pass through the separation system 20 before reaching the drive mechanism 212 and drill bit 214. In its default position (i.e., filtration mode), the separation system 20 can remove some or all of the solid particles from the drilling media. Figure 21Similarly, when the solid particles collected in the separation system 20 cause the upstream fluid pressure to reach a predetermined activation value, the separation system 20 is activated and placed in the fully activated position (i.e., flushing mode). When activated, the fluid flowing through the separation system 20 flushes the collected solids through the flushing outlet 26 and enters the annular space 216 between the separation system 20 and the formation 208. After deactivation, the fluid flowing through the separation system 20 in the default position is cleaned again before flowing into the drive mechanism 212.

[0060] Alternatively, such as Figure 21 and Figure 22 The separation system 22 shown can be activated and switched to flushing mode in response to a signal from the ground. For example, the signal can be a pressure pulse, an electrical signal, a magnetic signal, a mechanical signal (changes in rotational speed, changes in weight-on-bit (WOB) pressure, axial movement of the drill string, etc.), or any other type of signal that can be detected within the wellbore 204.

[0061] like Figure 23 As shown, when drilling wellbore 204, two or more separation systems 20 can be used in drill string 220. Upstream separation system 20A can be attached to the downstream end of drill string 220 in conjunction with upstream tool 230. Pipeline 232 can be attached between upstream tool 230 and downstream separation system 20B. Drive mechanism 212 and drill bit 214 can be attached below downstream separation system 20B. Drive mechanism 212 can be configured to drive drill bit 214, while upstream tool 230 can be configured to generate vibration, activate valves or any actuation device, or power a generator. For example, drive mechanism 212 can include a positive displacement motor (e.g., a vane motor or Moyno motor), turbine, impact motor, or hammer, while upstream tool 230 can include a turbine, friction-reducing tool, or vibration-generating tool, or any other tool that benefits from the use of clean drilling fluid. Upstream separation system 20A can remove solid particles from drilling fluid pumped through drill string 220, allowing clean or filtered drilling fluid to flow into upstream tool 230. Downstream separation system 20B can remove solid particles from the drilling fluid, allowing clean or filtered drilling fluid to flow into drive mechanism 212. When one or both of separation systems 20A and / or 20B are activated (automatically or in response to a signal from the surface), the collected solid particles are flushed through flush outlets 26A and / or 26B, respectively. Upstream separation system 20A can be configured to filter particles of a certain size from the drilling fluid, while downstream separation system 20B can be configured to filter particles of a smaller size than those from upstream separation system 20A.

[0062] As used herein, “medium” means any liquid or compressible gas, which may include solid particles.

[0063] As used herein, “fluid” means any liquid or gas, which may include solid particles.

[0064] As used in this article, “open” in relation to an outlet, port or other opening means that fluid communication is open at the outlet, port or other opening.

[0065] As used in this article, “closed” in relation to an outlet, port or other opening means that fluid communication does not exist at the outlet, port or other opening.

[0066] Unless otherwise described or specified, each component in the device has a generally cylindrical shape and may be formed of steel, another metal, or any other durable material. Parts of the separation system 20 may be formed of abrasion-resistant materials such as tungsten carbide, ceramic, or ceramic-coated steel.

[0067] Each device described in this disclosure may include any combination of the components, features, and / or functions described in each embodiment of the various device embodiments. Each method described in this disclosure may include any combination of steps described in any order, including combinations of steps missing certain descriptions and steps used in individual embodiments. Any numerical range disclosed herein includes any subrange within that range. “plurality” means two or more. “Above” and “below” should be understood respectively to mean upstream and downstream, such that the directional orientation of the device is not limited to a vertical arrangement.

[0068] While preferred embodiments have been described, it should be understood that these embodiments are merely illustrative, and the scope of the invention will be defined only by the appended claims (which, when given the full scope of equivalents, many variations and modifications that would naturally conceive of by those skilled in the art upon review of the invention).

Claims

1. A downhole separation system, comprising: A housing, the housing including a housing bore and one or more flushing outlets extending radially from the housing bore to the outer surface of the housing; A screen, wherein the screen is disposed within the inner hole of the housing, and the screen includes a plurality of openings; The plurality of openings in the screen filter at least a portion of any solids contained in the medium flowing through the downhole separation system; wherein the one or more flush outlets flush at least a portion of the filtered solids through the one or more flush outlets and out of the outer surface of the housing as the medium flows through the downhole separation system; and A sliding assembly configured to move within the housing bore between a default position and an active position; wherein the sliding assembly is configured to close one or more flush outlets in the default position and open one or more flush outlets in the active position; wherein the sliding assembly is flow rate controlled in the default position and pressure controlled in the active position. The core of the sliding component includes: The upstream center hole and the downstream center hole are separated by the mandrel core; One or more mandrel filter ports, each mandrel filter port extending radially from the upstream central hole to the outer surface of the mandrel; wherein the mandrel filter port is open in the default position and closed in the active position; One or more mandrel flushing ports, each mandrel flushing port extending radially from the upstream center hole to the outer surface of the mandrel; wherein the mandrel flushing port is configured to be axially distanced from the mandrel filter port; wherein the mandrel flushing port is closed in the default position and open in the active position; One or more lower mandrel ports, each lower mandrel port extending radially from the downstream center hole to the outer surface of the mandrel; wherein the lower mandrel port is open in the default position and closed in the active position.

2. The downhole separation system of claim 1 further includes a damping mechanism comprising a fluid channel connecting two damping chambers, wherein fluid flow through the fluid channel slows the rate at which the sliding assembly moves between the default position and the activated position.

3. The downhole separation system according to claim 2, wherein, The fluid channel includes one or more nozzles.

4. The downhole separation system according to claim 2, wherein, The fluid channel includes an annular space.

5. The downhole separation system of claim 1 further includes a spring disposed within the inner bore of the housing, wherein the spring is configured to bias the sliding assembly toward the default position.

6. The downhole separation system according to claim 1, wherein, The upstream center hole includes a tapered surface located between the mandrel filter port and the mandrel flush port.

7. The downhole separation system according to claim 1, wherein, A portion of the mandrel is slidably disposed through the central hole of the screen; wherein the lower port of the mandrel is disposed within the central hole of the screen in the default position; wherein the mandrel flushing port is disposed within the central hole of the screen in the activated position.

8. The downhole separation system according to claim 7, further comprising: A screen cavity, the screen cavity being defined between the outer surface of the mandrel and the inner surface of the screen; and A collection chamber is defined between the outer surface of the screen and the inner hole of the housing.

9. The downhole separation system according to claim 8, further comprising: A first diverter includes a central aperture and one or more first diverter channels, each first diverter channel extending axially between the central aperture and an outer surface of the first diverter; wherein a portion of a mandrel is slidably disposed through the central aperture of the first diverter, such that a mandrel flushing port is disposed within the central aperture of the first diverter in a default position, and a mandrel filtering port is disposed within the central aperture of the first diverter in an activated position. and The second diverter includes a central aperture and one or more second diverter channels, each second diverter channel extending axially between the central aperture of the second diverter and an outer surface of the second diverter; wherein a portion of the mandrel is slidably disposed through the central aperture of the second diverter, such that a lower port of the mandrel is disposed within the central aperture of the second diverter in the activated position; wherein the screen extends between the first diverter and the second diverter.

10. The downhole separation system of claim 1, further comprising an outer valve sleeve fixedly disposed within the inner bore of the housing, the outer valve sleeve including a central bore and one or more sleeve ports extending radially from the central bore of the outer valve sleeve to an outer surface of the outer valve sleeve; wherein a flushing outlet is formed between the outer surface of the outer valve sleeve and the inner bore of the housing; and wherein the flushing outlet fluidly connects the one or more sleeve ports to the one or more flushing outlets of the housing.

11. The downhole separation system according to claim 10, wherein, The one or more sleeve ports and the one or more flushing outlets are spaced apart by an axial distance.

12. The downhole separation system according to claim 10, wherein, The sliding assembly further includes an inner valve sleeve connected to the downstream end of the mandrel; wherein the inner valve sleeve is slidably disposed within the central hole of the outer valve sleeve; wherein, in the default position, the inner valve sleeve closes the one or more sleeve ports; wherein, in the activated position, the inner valve sleeve opens the one or more sleeve ports.

13. The downhole separation system of claim 12, further comprising a spring disposed within the inner bore of the housing, wherein the spring is configured to bias the sliding assembly toward the default position, wherein, The sliding assembly also includes a piston connected to the downstream end of the inner valve sleeve; wherein the spring is disposed around a portion of the piston.

14. The downhole separation system according to claim 13, wherein, The piston includes a sealing block having an enlarged outer diameter, the sealing block engaging the housing bore to create a first damping chamber and a second damping chamber; wherein the piston also includes one or more nozzles extending from a first shoulder of the sealing block to a second shoulder; wherein each of the one or more nozzles fluidly connects the first damping chamber and the second damping chamber.

15. A method for filtering a medium flowing in a wellbore, comprising the following steps: a) Provide a first separation system, wherein the first separation system is the downhole separation system according to claim 1; b) Position the first separation system within the drill string or coiled tubing string inside the wellbore; c) Allow the medium to flow through the drill string or the coiled tubing string and into the housing bore of the first separation system; d) When the sliding component is in the default position, at least a portion of any solids contained in the medium is filtered by guiding the medium into the plurality of openings of the screen; The filtered solids remain in the collection chamber; e) Activate the first separation system to move the sliding assembly to the activated position to flush at least a portion of the filtered solids from the collection chamber through the one or more flushing outlets out of the outer surface of the housing and into the annular space surrounding the housing; f) Deactivate the first separation system to allow the sliding assembly to slide back to the default position to filter the medium flowing through the housing borehole; wherein steps b) through f) are performed without removing the first separation system from the wellbore; In step e), the first separation system is activated by adjusting the flow rate of the medium through the first separation system; in step f), the first separation system is deactivated by adjusting the pressure difference between the inner hole of the housing and the annular space.

16. The method according to claim 15, wherein, In step a), the first separation system further includes a damping mechanism comprising a fluid channel connecting two damping chambers, and wherein in step e), the fluid flow through the fluid channel slows the rate at which the sliding component moves to the activated position.

17. The method according to claim 15, wherein, Step a) further includes providing a second separation system, the second separation system being the downhole separation system of claim 1, wherein the plurality of openings of the second separation system are configured to filter particle sizes smaller than those of the plurality of openings of the first separation system; Step b) further includes positioning the second separation system downstream of the first separation system within the drill string or coiled tubing string in the wellbore; step c) further includes allowing the medium to flow through the housing bore of the second separation system; and step d) further includes filtering at least a portion of any solids contained in the medium when the sliding assembly of the second separation system is in the default position, wherein the solids filtered by the sliding assembly of the second separation system are less than the solids filtered by the sliding assembly of the first separation system.

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