CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to US provisional patent application number 62/779,150 filed December 13, 2018, the entire contents of which are incorporated by reference herein.

TECHNICAL FIELD

[0002] The application relates generally to valves and, more particularly, to float valves for hydrocarbon extraction operations.

BACKGROUND

[0003] In hydrocarbon extraction operations, a drill string is an assembly of drill pipes and other components that provides an internal fluid passage along its axis, to transmit components and fluids down hole into the ground. The drill string also provides a guide path for fluid to circulate back up to the surface. Drill pipes make up the majority of the drill string, and are joined at mating ends, typically using threaded connections.

[0004] A component found in some drill strings is a float valve housed in a section of the drill string. The functionality of the float valve is to allow circulation of fluid in a desired direction (typically down hole) based on the pressure of fluid upstream of the valve. If there is a flow reversal in the drill string, the float valve is meant to close and thus prevent fluid from flowing in an undesired direction.

[0005] Such float valves may help with Managed Pressure Drilling (MPD), which allows for control of the bottom hole pressure (BHP) by changing a direction of pressure back toward the bottom hole. Such valves may also help with Under Balanced Drilling (UBD), which may help to decrease drill pipe connection times by adding a float valve at every 200 m to 500 m of connections.

[0006] Known float valves have experienced several issues. One such issue is that the spring in the valve failed, and the valve remained in the open configuration even when it was not supposed to. Another such issue is the phenomenon of “washing out” of the valve’s components away from the valve due to a force exerted by the fluid in the drill string.

SUMMARY

[0007] There is provided a valve, comprising: a housing extending along a longitudinal axis and having a first part and a second part spaced axially from the first part, and a housing sleeve extending between and mounted to the first and second parts, the first part having a passage therein in fluid communication with a valve chamber disposed between the first and second parts and delimited by the housing sleeve, the second part having a stem passage extending therein; a valve head and a valve stem extending axially away from the valve head, the valve head disposed within the housing sleeve and displaceable within the valve chamber along the longitudinal axis, the valve stem displaceable into the stem passage of the second part, the valve stem having an abutment member abuttable against the second part of the housing; and a biasing member about the valve stem, the biasing member having a first end abutted against the valve head and a second end abutted against the second part of the housing, the biasing member operable to displace the valve head against the first part of the housing to block the passage; the valve head and the valve stem being displaceable between an open position of the valve and a closed position of the valve, the valve head in the open position disposed within the valve chamber and the abutment member of the valve stem abutted against the second part, the valve head in the closed position abutted against the first part by the biasing member.

[0008] There is provided a method of conveying fluid in a single direction through a valve, the method comprising: biasing a valve head and a valve stem of the valve in a direction opposite to the single direction with a biasing member of the valve; and displacing the valve head and the valve stem in the single direction when a force of the fluid exceeds a biasing force of the biasing member, until part of the valve stem abuts against a downstream portion of the valve, the biasing member being less than fully compressed when the valve stem abuts against the downstream portion of the valve. [0009] There is provided a drill string float valve, comprising: a housing extending along a longitudinal axis and having a first part and a second part spaced axially from the first part and connected thereto, the first part having a passage therein in fluid communication with a valve chamber disposed between the first and second parts; a valve head and a valve stem extending axially away from the valve head, the valve head and the valve stem being displaceable within the valve chamber along the longitudinal axis, the valve stem having an abutment member abuttable against the second part of the housing; and a biasing member having a first end abutted against the valve head and a second end abutted against the second part of the housing, the biasing member operable to displace the valve head against the first part of the housing to block the passage; the valve head and the valve stem being displaceable between an open position of the valve and a closed position of the valve, the valve head in the open position disposed within the valve chamber and the abutment member of the valve stem abutted against the second part such that the biasing member is less than fully compressed, the valve head in the closed position abutted against the first part by the biasing member.

DESCRIPTION OF THE DRAWINGS

[0010] Reference is now made to the accompanying figures in which:

[0011] Fig. 1 A is a partial cross-sectional view of a valve;

[0012] Fig. 1 B is another partially-sectioned view of the valve of Fig. 1A;

[0013] Fig. 1C is an end view of the valve of Fig. 1 A;

[0014] Fig. 1 D is a cross-sectional view of the valve of Fig. 1A, shown in an open position;

[0015] Fig. 1 E is another cross-sectional view of the valve of Fig. 1A, shown in a closed position;

[0016] Fig. 1 F is an enlarged view of the portion IF-IF in Fig. 1 E;

[0017] Fig. 1G is a perspective view of the valve of Fig. 1A; [0018] Fig. 1 H is another perspective view of the valve of Fig. 1A;

[0019] Fig. 11 is a cross-sectional view of the valve of Fig. 1A taken along the line ll-ll in Fig. 1G;

[0020] Fig. 1J is another perspective view of the valve of Fig. 1A showing internal features thereof in dotted lines;

[0021] Fig. 1 K is a perspective view of a biasing member of the valve of Fig. 1 A;

[0022] Fig. 2A is a cross-sectional view of another valve shown in the closed position;

[0023] Fig. 2B is another cross-sectional view of the valve of Fig. 2A, the valve shown in the open position;

[0024] Fig. 2C is a perspective view of the valve of Fig. 2A;

[0025] Fig. 2D is a partially-sectioned view of the valve of Fig. 2A;

[0026] Fig. 2E is another perspective view of the valve of Fig. 2A;

[0027] Fig. 3A is a perspective view of another valve;

[0028] Fig. 3B is another perspective view of the valve of Fig. 3A, shown in a closed position;

[0029] Fig. 3C is another perspective view of the valve of Fig. 3A, shown in an open position;

[0030] Fig. 3D is a cross-sectional view of the valve of Fig. 3A, shown in a closed position;

[0031] Fig. 3E is a cross-sectional view of the valve of Fig. 3A, shown in an open position;

[0032] Fig. 4 is a cross-sectional view of the valve of Fig. 3A showing a valve head;

[0033] Fig. 5 is a cross-sectional view of the valve of Fig. 1 A showing a valve head; [0034] Fig. 6A is a cross-sectional view of a valve shown within a housing; and [0035] Fig. 6B is another partially sectioned view of the valve and housing of Fig. 6A. DETAILED DESCRIPTION

[0036] Fig. 1A illustrates a valve 10 of a type for use, for example, in a drill string of a hydrocarbon extraction operation. The valve 10 of the depicted embodiment is sometimes referred to as a“float” valve 10, or a“drill string float” valve 10. In one example of a use of the valve 10, the valve 10 is housed in a section of the drill string. The functionality of the valve 10 is to allow circulation of fluid in a desired direction D (which is downward in Fig. 1A), and to prevent the circulation of fluid in a direction opposite to the desired direction D. The valve 10 operates between an open position shown in Figs. 1 D, during which it permits the circulation of fluid through the valve 10 and in the desired direction D, and a closed position shown in Figs. 1A, 1 B and 1 E during which it blocks the circulation of fluid through the valve 10.

[0037] Referring to Figs. 1A and 1 B, the valve 10 has a housing 20 which forms the stationary corpus of the valve 10 and provides structure thereto. The housing 20 is used to mount the valve 10 to a component of the drill string, such as a drill pipe, such that the valve 10 is fixed in position within the drill string. The housing 20 is an elongated body that is longer than it is wide. The housing 20 extends along a longitudinal axis 21. The longitudinal axis 21 in the depicted embodiment is a center axis of the housing 20. The housing 20 has a first part 22 and a second part 24. The first part 22 is a one-piece integral body. The second part 24 is a one-piece integral body. The first and second parts 22,24 are spaced apart from each other in a direction along the axis 21 of the housing 20, and are also connected to each other. The connection or joining of the first and second parts 22,24 may take different forms, and is described in greater detail below. In the depicted embodiment, the valve 10 has an upright or vertical orientation, and the first part 22 forms an upper part of the housing 20, while the second part 24 forms a lower part of the housing 20. In an embodiment where the valve 10 has a different orientation, for example a substantially horizontal orientation, the first part 22 forms an upstream part of the housing 20 and the second part 24 forms a downstream part of the housing 20. The first part 22 may therefore be understood as the portion of the housing 20 with which fluid engages first, and thus before the fluid engages the second part 24 of the housing 20.

[0038] The housing 20 has a housing sleeve 25 extending between, and mounted to, the first and second parts 22,24. In Figs. 1A and 1 B, the housing sleeve 25 is part of the second part 24 of the housing 20, and includes a threaded end 25A to threadingly engage a threaded portion 22D of the first part 22 to connect the first and second parts 22,24 together. The position of the first and second parts 22,24 is therefore fixed relative to one another, such that the first and second parts 22,24 do not experience relative movement. The first and second parts 22,24 are easily disconnected, thereby allowing the housing 20 to be relatively easily disassembled for repairs or replacement. The second part 24 serves as a stopper to prevent wash out of components of the valve 10. The second part 24 has a stem passage 24B extending through the second part 24 to slidingly receive a stem, as described in greater detail below. In an alternate embodiment, the stem passage 24B extends into the second part 24 and has a floor defined in the second part 24. In such an embodiment, the stem passage 24B is a depression or groove in the second part 124.

[0039] In the open position shown in Fig. 1 D, fluid flows through the valve 10. The first part 22 has a passage 26 defined therein which allows for fluid to flow through the first part 22. The passage 26 is defined or circumscribed by inner walls of the first part 22. In the depicted embodiment, the passage 26 is cylindrical in shape and is coaxial with the axis 21. The passage 26 may have other shapes in alternate embodiments. The housing 20 also has a valve chamber 28 located between the first and second parts 22,24. When the valve 10 is in the open position, fluid flows through the passage 26 in the first part 22 and then into the valve chamber 28. The fluid exits the valve 10 by exiting the valve chamber 28 to flow downstream of the valve 10. The valve chamber 28 may assume different configurations to achieve such functionality. In Fig. 1 D, the valve chamber 28 is partially open (or partially closed), and is partially delimited by walls of the housing sleeve 25. In alternate embodiments, some of which are described below, the valve chamber 28 is completely closed except for a downstream outlet. Regardless of their configuration, the valve chamber 28 and the passage 26 in the first part 22 define a flow path for fluid through the valve 10. [0040] The housing 20 may assume any suitable shape, or have any suitable components or arrangements thereof, to achieve the functionality ascribed to it herein. Referring to Figs. 1 B, 1C, 1G and 11, the housing 20 has planar walls 21A and curved walls 21 B. The curved walls 21 B delimit the boundaries of the valve chamber 28 and partially close same. The valve chamber 28 is therefore open on two sides of the housing 20, and closed on two sides. The planar walls 21A give the housing 20 a slimmer profile. In Figs. 1 B, 1C, 1G and 11, each planar wall 21A extends between two curved walls 21 B. The planar walls 21 A are part of the second part 24 of the housing 20. Each of the planar walls 21A lie in, or define, a plane. Referring to Figs. 1C, 1G and 11, the second part 24 has two planar walls 21A which lie in parallel planes. The two planar walls 21A are spaced apart from each other in a direction being perpendicular to their planes. The two planar walls 21A are spaced apart from each other in a direction being parallel to a plane that is perpendicular to the axis 21. Referring to Fig. 1C, the planar walls 21A are spaced inwardly from the curved walls 21 B. The planar walls 21A are positioned closer to the longitudinal axis 21 than the curved walls 21 B.

[0041] Referring to Figs. 1C, 1G, 11, 1 H and 1 J, the planar walls 21A of the housing 20 of the valve 10 have flow channels 60 formed therein. The flow channels 60 are depressions or grooves that extend inwardly from the surface of the planar walls 21A toward the longitudinal axis 21. The flow channels 60 are depressions or grooves that extend inwardly from the surface of the planar walls 21A only partially into the body of the second part 24. The flow channels 60 are disposed in the planar walls 21A adjacent to the curved walls 21 B of the housing 120. The flow channels 60 of each planar wall 21A are spaced apart from each other by a remainder of the planar walls 21A. Each flow channel 60 on each planar wall 21A is aligned with a flow channel 60 on the other planar wall 21A, such that a plane being perpendicular to the planar walls 21A extends through the aligned flow channels 60. The flow channels 60 have a length defined along the longitudinal axis 21. The flow channels 60 are elongated and extend in a direction parallel to the longitudinal axis 21. In the depicted embodiment, the flow channels 60 are disposed only in the second part 24 of the housing 120. The flow channels 60 help to increase the flow area. Flow speed may decrease as a result of the flow channels 60, which may help reduce the risk of a washing out of components of the valve 10.

Referring to Fig. 11, the cross-sectional shape of the second part 24 with the flow channels 60 is similar to that of an anchor. The cross-sectional shape of the second part 24 is substantially rectangular, except for the curved walls 21 B. The flow channels 60 have a semi-circular shape in cross-section.

[0042] The valve 10 also has internal components which displace relative to the housing 20 to open and close the valve 10. Still referring to Figs. 1 D and 1 E, the valve 10 has a valve piston or head 32 and a valve stem 34 extending away from the valve head 32 in a direction parallel to the axis 21. The valve head 32 and the valve stem 34 are coaxial with the axis 21. In the depicted embodiment, the valve head 32 and the valve stem 34 are integral with each other and form a singular component. In an alternate embodiment, the valve head 32 and the valve stem 34 are two separate components which are removably connectable to one another.

[0043] The valve head 32 and the valve stem 34 are displaceable together within the valve chamber 28. The valve head 32 and the valve stem 34 displace along the axis 21 in a first direction D1 toward the first part 22, and in a second direction D2 opposite to the first direction D1 toward the second part 24. Upstream fluid pressure causes the valve head 32 and the valve stem 34 to displace in the direction D2, and a biasing force, described in greater detail below, causes the valve head 32 and the valve stem 34 to displace in direction D1. The valve head 32 is sized and shaped to be trapped within the valve chamber 28 between the first and second parts 22,24, and may take any suitable shape to achieve such functionality. For example, the valve head 32 is shaped to engage and be flush with the inner walls of the sleeve 25. The valve head 32 may therefore be prevented from“washing out” of the housing 20 of the valve 10 in response to strong fluid pressure in the drill string. The valve head 32 and the valve stem 34 may assume any suitable shape, or have any suitable components or arrangements thereof, to achieve the functionality ascribed to them herein. In Figs. 1 D and 1 E, the valve head 32 and the valve stem 34 are cylindrical bodies. The diameter of the valve stem 34 is less than the diameter of the valve head 32. The valve head 32 is disposed within the housing sleeve 25 between its ends axially-opposed ends. The valve head 32 is slidingly displaceable along the inner surface of the curved walls 21 B of the housing sleeve 25. The valve stem 34 is displaceable into and through the stem passage 24B of the second part 24. [0044] The valve 10 also has one or more components which operate to maintain the valve 10 in the closed position by default. Referring to Figs. 1 D, 1 E and 1 K, the valve 10 has a biasing member 40 which exerts a biasing force against the valve head 32 to displace it in the direction D1 to maintain the valve 10 in the closed position shown in Fig. 1 E. The biasing member 40 operates to displace the valve head 32 in the direction D1 against the first part 22 of the housing 20 to block the passage 26. When the pressure of the fluid in the drill string upstream of the valve 10 is high enough, the force exerted by the biasing member 40 is overcome, and the valve 10 is allowed to open by displacing the valve head 32 in the direction D2, as shown in Fig. 1 D.

[0045] In the depicted embodiment, the biasing member 40 is in the form of a coiled compression spring 41 which is coaxial with the axis 21. The spring 41 exerts force on the valve head 32 by expanding. The expanded state of the spring 41 is the default position of the spring 41 , such that the valve 10 is by default maintained in the closed position. The biasing member 40 has a first end 42 abutted against the valve head 32 and a second end 44 abutted against the second part 24. The biasing member 40 is a one-piece body extending uninterrupted between its first and second ends 42,44 and between the valve head 32 and the second part 24. In the depicted embodiment, the biasing member 40 is mounted about the stem 34, and is positioned radially inwardly of the sleeve 25. The biasing member 40 is positioned between valve head 32 and the second part 24, and thus partially shielded from the fluid flow when the valve 10 is in the open position, as shown in Fig. 1 D. The biasing member 40 is trapped between the valve head 32 and the second part 24, which may help prevent the biasing member 40 from washing out of the housing 20 of the valve 10 in response to strong fluid pressure in the drill string.

[0046] Referring to Figs. 1 D and 1 E, the valve stem 34 has an abutment member 35 which is intended to abut against a portion of the second part 24 to prevent further displacement of the valve head 32 and the valve stem 34 in the direction D2. The abutment member 35 may help the spring 41 from being excessively compressed, and thus from being structurally damaged. The spring is operable between a fully extended position, which may be reached when the valve 10 is in the closed position, and a fully compressed position. The abutment member 35 is positioned on the valve stem 34 to prevent the spring 41 from being in the fully compressed position when the abutment member 35 abuts against the second part 24 in the open position of the valve 10, as shown in Fig. 1 D. The abutment member 35 therefore helps to limit the maximum compressibility of the spring 41 , and thus helps the prevent the spring 41 from being excessively compressed. The valve head 32 and the valve stem 34 arrive at a hard stop before the spring 41 might be completely crushed by fluid pressure acting to displace the valve head 32 and the valve stem 34 in the direction D2. The abutment member 35 may therefore help prevent the spring 41 from failing, it being appreciated that a failed spring might prevent the valve 10 from closing.

[0047] Different configurations of the abutment member 35 are possible to achieve this functionality and within the scope of the present disclosure. In Figs. 1 D and 1 E, the valve stem 34 includes an elongated first part 34A and an elongated second part 34B extending from the first part 34A. The second part 34B in the depicted embodiment is longer than the first part 34A. The first part 34A has a first diameter and the second part 34B has a second diameter that is less than the first diameter. The transition between the first and second parts 34A.34B of the valve stem 34 thus forms a flange 35A, which forms the abutment member 35 in the depicted embodiment. The flange 35A protrudes radially outwardly from the smaller-diameter second part 34B of the valve stem 34 at the transition. The flange 35A has an orientation that is perpendicular to the axis 21.

[0048] The flange 35A is intended to abut against a portion of the second part 24. Specifically, and referring to Figs. 1 D and 1 E, the stem passage 24B of the second part 24 has a first part 24B’ and a second part 24B”. The first and second parts 24B’,24B” are coaxial with the axis 21. The second part 24B” in the depicted embodiment is longer than the first part 24B’. The first part 24B’ has a first diameter and the second part 24B” has a second diameter that is less than the first diameter. The transition between the first and second parts 24B’,24B” of the stem passage 24B thus forms a landing 24C. The landing 24C is a wall in the depicted embodiment which extends radially-outwardly from the second part 24B” of the stem passage 24B. The flange 35A is configured to abut against the landing 24C to prevent further displacement of the valve head 32 and the valve stem 34, and to prevent crushing or over compression of the biasing member 40, as shown in Fig. 1 D. The biasing member 40 is thus prevented from being in the fully compressed state when the flange 35A abuts against the landing 24C. The radially-outermost diameter of the landing 24C is greater than the radially- outermost diameter of the flange 35A in the depicted embodiment.

[0049] The biasing member 40 is mounted about the valve stem 34. When the valve 10 is in the closed position, as shown in Fig. 1 E, the biasing member 40 extends over both the first and second parts 34A.34B of the valve stem 34. When the valve 10 is in the open position, as shown in Fig. 1 D, the biasing member 40 extends over only the first part 34A of the valve stem 34. The biasing member 40 is always present in the first part 24B’ of the stem passage 24B. The biasing member 40 is never present in the second part 24B” of the stem passage 24B. In both the open and closed positions of the valve 10, the second end 44 of the biasing member 40 rests against and is abutted against the landing 24C.

[0050] The valve 10 operates as follows between the open position and the closed position. It will be understood that the open and closed positions shown in the figures are fully opened positions and fully closed positions of the valve 10 in which further displacement of the valve head 32 and the valve stem 34 is prevented. The valve 10 is also operable between partially opened and partially closed positions between the fully opened and closed positions shown, where further displacement of the valve head 32 and the valve stem 34 is possible.

[0051] Referring to Figs. 1 D and 1 E, in response to a fluid pressure upstream of the valve 10 which is greater than the force exerted by the biasing member 40, the valve head 32 and the valve stem 34 are caused to displace in the direction D2 to open the valve 10. The valve head 32 in the open position shown in Fig. 1 D is disposed within the valve chamber 28 and the abutment member 35 is abutted against the second part 24 to prevent further displacement of the valve head 32 and the valve stem 34, and to prevent crushing of the biasing member 40.

[0052] Referring to Figs. 1 D and 1 E, when the fluid pressure upstream of the valve 10 is less than the biasing force exerted by the biasing member 40, or where there is reverse flow of fluid in the direction D1 , the valve head 32 and the valve stem 34 are caused to displace in the direction D1 to close the valve 10 by a biasing force provided by the biasing member 40. The valve head 32 in the closed position of the valve 10 shown in Fig. 1 E is abutted against the first part 22 by the biasing member 40 to block the passage 26 and close the valve 10, thus preventing fluid from flowing through the valve 10.

[0053] Referring to Figs. 1 E and 1 F, the valve 10 has a cap 50. The cap 50 is mounted to the valve head 32 and displaceable therewith in the valve chamber 28. The cap 50 extends between a first end 52A mounted to, or abutting against, the valve head 32, and a second end 52B extending away from the first end 52A in a direction toward the second part 24. In the depicted embodiment, the cap 50 abuts against a seal 39 secured against a flange of the valve head 32. The cap 50 is an annular body and has a hollow interior. In Fig. 1 E, the cap 50 has an axial length defined between the first and second ends 52A.52B that is less than that of the biasing member 40 in its uncompressed state. In Fig. 1 E, the cap 50 has an axial length defined between the first and second ends 52A.52B that is less than that of the valve chamber 28. The cap 50 is disposed about a portion of the biasing member 40 to house and protect the biasing member 40 in a compressed stated. The biasing member 40 is thus positioned radially between the cap 50 and an outer surface of valve stem 34. An inner flange 54 of the cap 50 extends radially inwardly from an outer surface of the cap 50, and defines an extremity of the cap 50 and abuts against the first end 42 of the biasing member 40.

[0054] When the valve 10 is in the closed position, as shown in Fig. 1 E, the biasing member 40 is in its expanded state, and the cap 50 encloses part of the biasing member 40. When the valve 10 is in the open position, as shown in Fig. 1 D, the biasing member 40 is in its compressed state, and the cap 50 encloses the entirety of the biasing member 40 not in the second part 24. In its compressed state, the biasing member 40 is thus partly shielded in the first part 24B’ of the stem passage 24B, and partly shielded by the enclosure defined when the cap 50 is abutted against the second part 24. This protects the biasing member 40, and may help avoid an occurrence where the biasing member 40 could be washed out by the flow of fluid through the valve chamber 28 of the valve 10. When the valve 10 is in the open position, as shown in Fig. 1 D, the second end 52B of the cap 50 abuts against a wall 24A of the second part 24 to prevent further displacement of the cap 50 in the direction D2, and thus further displacement of the valve head 32 and the valve stem 34 in the direction D2.

[0055] Figs. 2A to 2E show another embodiment of the valve 110. The valve 110 is similar to the valve 10 described above. Therefore, any features of the valve 110 shown in Figs. 2A to 2E that are also in the valve 10 described above may be attributed the same reference numbers and associated description. The valve 110 is free of the cap 50 of the valve 10 described above. The biasing member 40 of the valve 110 is trapped between the valve head 32 and the second part 24, which may help prevent the biasing member 40 from washing out of the housing 20 of the valve 110 in response to strong fluid pressure in the drill string. The housing 20 of the valve 110 has planar walls 121A and curved walls 21 B. The planar walls 121A of the valve 110 are continuous. The planar walls 121 A are free of depressions and flow channels. The curved walls 21 B delimit the boundaries of the valve chamber 28 and partially close same. The valve chamber 28 is therefore open on two sides of the housing 20, and closed on two sides. The planar walls 121A give the housing 20 a slimmer profile. Each planar wall 121A extends between two curved walls 21 B. The planar walls 121 A are part of the second part 24 of the housing 20.

[0056] Figs. 3A to 3E show another embodiment of the valve 210. In the depicted embodiment, the valve chamber 228 is completely open, and is defined as a uninterrupted void between the first and second parts 222,224 of the housing 220. The housing 220 may assume any suitable shape, or have any suitable components or arrangements thereof, to achieve the functionality ascribed to it herein. For example, in the depicted embodiment, a radially outer surface 222A of the first part 222 (i.e. the surface of the first part 222 furthest from the axis 221 in a direction radial thereto) has seal members 223, such as gaskets, and O-rings. The seal members 223 help the valve 210 to form a fluid seal with the inner wall of the drill pipe when the housing 220 is mounted thereto. The first part 222 also has flow guide vanes 222B disposed in the passage 226, and extending radially outwardly from a hub 222C. The flow guide vanes 222B help to smooth out and guide the fluid flowing through the passage 226. In the depicted embodiment, the second part 224 has a distal ring 224A extending outwardly from a mounting shaft 224B which is coaxial with the axis 221. The distal ring 224A has ribs 224C which reinforce the compressive strength of the second part 224 at the distal or downstream end of the housing 220. The distal ring 224A forms a foot of the valve 210.

[0057] In Figs. 3A to 3E, the first part 222 is connected to the second part 224 via a housing shaft 225. The housing shaft 225 is coaxial with the axis 221 and extends between and fixedly mounts the first and second parts 222,224 together. The position of the first and second parts 222,224 is therefore fixed relative to one another, such that the first and second parts 222,224 do not experience relative movement. The housing shaft 225 is an internal component of the housing 220. At least part of the housing shaft 225 is not exposed to the fluid flowing through the valve 210. In the depicted embodiment, the housing shaft 225 has a smooth outer surface 225A located between threaded ends 225B. The threaded ends 225B are engaged with similarly threaded grooves in the first part 222 and the mounting shaft 224B of the second part 224 to connect the first and second parts 222,224 together. In the depicted embodiment, the first and second parts 222,224 are easily disconnected, thereby allowing the housing 220 to be relatively easily disassembled for repairs or replacement.

[0058] In the depicted embodiment, and as better shown in Figs. 3D and 3E, the abutment member 235 is in the form of a rim 235A at the distal, downstream end of the valve stem 234. The rim 235A abuts against the ribs 224C of the second part 224 to prevent further displacement of the valve head 232 and the valve stem 34 in the direction D2.

[0059] The valve head 232 and the valve stem 234 may assume any suitable shape, or have any suitable components or arrangements thereof, to achieve the functionality ascribed to them herein. For example, in the depicted embodiment, the valve stem 234 has a threaded segment 236 along its radially-outer surface. A rotatable nut 238 threadingly engages the threaded segment 236 to tighten a seal 239 against a flange of the valve head 232. The seal 239 engages an inner wall of the first part 222 of the housing 220 when the valve 210 is in the closed position, as better shown in Fig. 3D. In the depicted embodiment, the valve head 232 and the valve stem 234 are mountable about the housing shaft 225 and displaceable therealong within the valve chamber 228. The valve head 232 and the valve stem 234 are thus displaceable along the longitudinal axis 221 , and are slidingly mounted around the housing shaft 225 along its smooth outer surface 225A and between its threaded ends 225B. The sliding movement of the valve head 232 and the valve stem 234 is limited to being between the first and second parts 222,224. In the depicted embodiment, the biasing member 240 is mounted about the housing shaft 225, and is positioned between the outer surface 225A of the housing shaft 225 and a radially-inner surface of the valve stem 234. The valve head 232 and the valve stem 234 are hollow components in the depicted embodiment. The biasing member 240 is enclosed within valve head 232 and the valve stem 234, and thus shielded from the fluid flow. The biasing member 240 is also trapped between the valve head 232 and the mounting shaft 224B, which may help prevent the biasing member 240 from washing out of the housing 220 of the valve 210 in response to strong fluid pressure in the drill string. As better shown in Fig. 3E, the rim 235A abuts against the ribs 224C of the second part 224 to stop displacement of the valve head 232 and the valve stem 234 in the direction D2 before the spring 241 reaches its fully compressed position.

[0060] Referring to Fig. 4, the valve head 232 of the valve 210 includes an annular cap portion 232A integral with an annular skirt portion 232B. An outer surface of the skirt portion 232B forms an angle Q relative to the axis 221. Non-limiting examples of values for the angle Q range from 30° to 60°. Referring to Fig. 5, the valve head 32 of the valve 10 includes an annular cap portion 32A integral with an annular first skirt portion 32B, and the annular seal 39. A radially-outer surface of the first skirt portion 32B forms an angle b relative to the axis 21. Non-limiting examples of values for the angle b range from 30° to 60°. A radially-outer surface of the seal 39 forms an angle a relative to the axis 21. Non-limiting examples of values for the angle a range from 10° to 20°. The annular seal 39 is mounted about the valve stem 34 and against a flange 32E of the valve head 32. The annular seal 39 engages an inner surface of the curved walls 21 B of the housing sleeve 25, and is displaceable with the valve head 32. The cap portion 32A of the valve head 32 has an annular groove 32C. A seal 32D, made of rubber which is molded into the annular groove 32C, is displaceable with the valve head 32. The molded rubber seal 32D engages with an inner surface of the first part 22 that defines and delimits the passage 26 through the first part 22. A molded rubber seal 32D is believed to be better able to remain in the annular groove 32C in comparison to an O- ring.

[0061] Referring to Figs. 6A and 6B, the valve 10,110,210 is attached to a lock mandrel 170, typically by torquing the valve 10,110,210, and the valve 10,110,210 and lock mandrel 170 are positioned within a bore 172 of a sub 174 or housing. The lock mandrel 170 is locked inside the sub 174 using keys 176, two of which are shown. The lock mandrel 170 and the attached valve 10,110,210 may be retrieved from within the sub 174 using a wireline tool, such as a GS tool, in situations such as when they are stuck in the bore 172 of the sub 174. The sub 174 has an internal cross-sectional profile for accommodating the keys 176 of the lock mandrel 170. The sub 174 is torqued to the main drill string at both of its ends and becomes part of the drill string.

[0062] Referring to Figs. 1 D and 1 E, there is disclosed a method of conveying fluid in a single direction D2 through the valve 10,110,210. The method includes biasing the valve head 32 and the valve stem 34 in a direction D1 opposite to the single direction D2 with the biasing member 40. The method includes displacing the valve head 32 and the valve stem 34 in the single direction D2 when a force of the fluid exceeds a biasing force of the biasing member 40, until part of the valve stem 32 abuts against a downstream portion of the valve 10,110,210, such as the second part 24. The biasing member 40 is less than fully compressed when the valve stem 34 abuts against the downstream portion of the valve 10.

[0063] The housing 20,220 of the valve 10,110,210 described herein may be disassembled, meaning if ever a wash out of a component were to occur, the component may be replaced rather than having to replace the entire valve 10,110,210 or housing 20,220.

[0064] The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. For example, although the valve 10,110,210 is described herein as being used in a hydrocarbon extraction system, the valve 10,110,210 may be used in other fluid applications. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.