Energy Retaining Toe Valve
A downhole tool comprises a mechanical energy storage component that retains energy supplied by a first pressure increase and transfers such energy to actuate another component of the tool. In one aspect, the tool is a toe valve that is activated for opening ports thereon upon application of a first pressure and actuated to open the ports upon application of a second pressure lower than the first pressure.
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The present application claims priority to U.S. Application No. 63/203,522, filed on Jul. 26, 2021, the entire contents of which are incorporated herein by reference.
FIELD OF THE DESCRIPTIONThe present description generally relates to downhole tools, in particular tools for performing perforation operations. More particularly, the description relates to downhole tools that are capable of being activated when conducting a casing pressure test.
BACKGROUNDIn the field of hydrocarbon production, a wellbore is first drilled into a region containing a hydrocarbon-containing subterranean formation. The wellbore is then lined with casing, generally comprising a plurality of tubular components having an outer diameter that is less than the diameter of the wellbore, whereby an annular space is created between the casing and the wellbore. The casing is then secured in the wellbore with a cementing operation, wherein cement is passed through the casing and flowed into the annular space between the casing and the wellbore.
As is known in the art, prior to initiating production of a well, the cemented casing is pressure tested to ensure its integrity and that no leaks are present. Such pressure testing is often a requirement prescribed by governmental regulatory authorities. In conducting such pressure testing operation, the toe of the casing is sealed, and fluid is pumped into bore of the casing, thereby increasing the pressure therein to a specified value. This pressure is maintained for a specified period of time to conduct the test. If no pressure drop is found during the course of the test, the integrity of the casing is confirmed.
To achieve production of a cased well, fluid communication must be created between the hydrocarbon-containing reservoir and the internal bore of the casing. For this purpose, perforations are formed through the cement thereby forming fluid channels between the reservoir and the bore of the casing. These channels allow hydrocarbons from the reservoir to enter the casing and to ultimately be produced at surface. The perforations may be formed using various known tools and methods.
As known in the art, the perforation step may be performed using a toe valve, which comprises a tool formed as part of the casing. Such toe valves generally have a number of fluid ejection ports, usually circumferentially arranged, that are directed radially outwards towards the cement. Generally, the ejection ports are covered with burst plugs or discs or the like, which are designed to remain closed until a pre-set threshold pressure is reached. In operating toe valves, the bore of the casing is pressurized using a fluid, with the pressure being raised beyond a threshold pressure of the burst plugs. At this point, the ports are opened, and pressurized fluid supplied to the casing is ejected to the surrounding cement. The pressure of the fluid is sufficient to create perforations in the cement.
As will be understood, where a pressure integrity test must be performed on the casing, the testing pressure would necessarily exceed the pressure required to open the ports of the toe valve. Thus, with toe valves as described above, there is the problem that conducting a pressure test would result in premature opening of the ports of the toe valve. To address this problem, toe valves have been proposed that incorporate one or more mechanisms to prevent premature opening of the ports. Examples of such known toe valves include those described in: U.S. Pat. Nos. 9,359,864; 9,835,010; and 10,107,072. Another toe valve is disclosed by Chauffe, S. (Hydraulic Toe Valve Specifically Designed for a Cemented Environment, Am. Assoc. Drilling Eng., AADE-13-FTCE-25, 2013). Each of these known valves comprise an arrangement of moving sleeves and rupture discs that are adapted to be activated in multiple stages and generally involve complicated mechanisms that may be prone to failure.
The present description aims to provide an improvement over the known toe valves, in particular, toe valves that are designed to maintain closure of the perforation ports during the pressure testing phase.
SUMMARY OF THE DESCRIPTIONIn one aspect, there is provided a toe valve adapted to be deployed in a casing installed in a wellbore that is (i) adapted to be activated during a casing pressure test; and (ii) adapted to be actuated upon application of a second pressure lower than the casing test pressure, where actuation of the valve opens ports thereon.
In one aspect, there is provided a tool for deployment in a wellbore for performing a perforation step, the tool comprising a generally tubular structure adapted to be assembled on a tubular string, wherein the tool comprises:
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- a top sub, adapted to be connected to an uphole tubular component, and a bottom sub, adapted to be connected to a downhole tubular component;
- a tubular housing extending between the top sub and the bottom sub, the tubular housing having a first end connected to the top sub and a second end connected to the bottom sub, and a wall with at least one perforation port for fluid communication through the wall;
- a slidable sleeve provided within the tubular housing, the sliding sleeve being axially moveable with respect to the housing between a closed position, wherein the sleeve covers the at least one perforation port, and an open position, wherein the at least one perforation port is exposed allowing fluid communication through the wall of the tubular housing;
- the top sub including a plurality of pistons, wherein each piston comprises a respective first end and second end;
- the top sub including a biasing means for applying an axial force against the first ends of the pistons;
- at least one first valve adapted to permit pressurized fluid within the lumen of the tool to impinge on the second ends of the pistons and energize the biasing means; and,
- at least one second valve adapted to be actuated by the energized biasing means, whereby, upon actuation, the second valve provides a fluid channel between the lumen of the tool and the slidable sleeve.
In another aspect, there is provided a method of operating a tool deployed in a wellbore, the tool comprising a generally tubular structure adapted to be assembled on a tubular string, the tool comprising:
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- a top sub, adapted to be connected to an uphole tubular component, and a bottom sub, adapted to be connected to a downhole tubular component;
- a tubular housing extending between the top sub and the bottom sub, the tubular housing having a wall with at least one port for fluid communication through the wall;
- the housing including a slidable sleeve, wherein the sleeve is axially moveable between a closed position covering the at least one port, and an open position, wherein the at least one port is exposed allowing fluid communication through the wall of the tubular housing;
- the top sub including a biasing means;
- the method comprising:
- pressurizing the lumen of the tool with a fluid under a first pressure and actuating a first valve to permit the fluid to energize the biasing means;
- reducing the pressure within the lumen of the tool and actuating a second valve to permit fluid within the lumen to impinge on the sliding sleeve;
- pressurizing the lumen of the tool with a fluid under a second pressure to axially shift the sliding sleeve from the closed position to the open position; and,
- pressurizing the lumen of the tool with a pressurized fluid to force the pressurized fluid through the at least one port provided on the housing.
The features of certain embodiments will become more apparent in the following detailed description in which reference is made to the appended figures wherein:
As used herein, the term “sub” will be understood to mean a tubing string component, such as a tubular member, a coupling, a tool etc. as known in the art. As also known, a sub has a generally cylindrical structure and is adapted to be connected to adjacent tubular members, or other subs, to form the tubing string. As with typical tubular members, a sub may have a female or “box” end and a male or “pin” end. The box end includes an internal threaded portion that is adapted to receive and threadingly engage an external thread provided on a pin end of an adjacent component (e.g., a tubular member, a sub, or a tool etc.). In this way, all components of the tubular string are connected together in an end-to-end manner.
The term “tool” as used herein will be understood to refer commonly known tubing string components that are used for performing various tasks. Examples of tools include valves, such as sliding sleeve valves, packers, and the like. Cementing tools are also known in the art, and these include plugs, shoes, collars etc.
The term “port” will be understood to mean an opening, aperture, or the like, that is provided to allow the flow of fluid therethrough. As used herein, a port comprises an opening provided on the wall of a tubular body for forming a fluid channel into the lumen of the body.
The terms “comprise”, “comprises”, “comprised” or “comprising” may be used in the present description. As used herein (including the specification and/or the claims), these terms are to be interpreted as open-ended terms and as specifying the presence of the stated features, integers, steps, or components, but not as precluding the presence of one or more other feature, integer, step, component, or a group thereof as would be apparent to persons having ordinary skill in the relevant art. Thus, the term “comprising” as used in this specification means “consisting at least in part of”. When interpreting statements in this specification that include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as “comprise” and “comprised” are to be interpreted in the same manner.
The phrase “consisting essentially of” or “consists essentially of” will be understood as generally closed terms, with the exception of allowing inclusion of additional items, materials, components, steps, or elements, that do not materially affect the basic and novel characteristics or function of the item(s) used in connection therewith. For example, trace elements present in a composition, but not affecting the composition's nature or characteristics would be permissible if present under the “consisting essentially of” language, even though not expressly recited in a list of items following such terminology. When using an open-ended term, such as “comprising” or “including”, it will be understood that direct support should be afforded also to “consisting essentially of” language as well as “consisting of” language as if stated explicitly and vice versa. In essence, use of one of these terms in the specification provides support for all of the others.
The term “and/or” can mean “and” or “or”.
Unless stated otherwise herein, the articles “a” and “the”, when used to identify an element, are not intended to constitute a limitation of just one and will, instead, be understood to mean “at least one” or “one or more”.
The terms “top”, “bottom”, “up”, or “down” may be used herein. It will be understood that these terms will be used purely for facilitating the description and, unless stated otherwise, are not intended in any way to limit the description to any spatial or positional orientation. In one example, the terms “top” or “uphole” may be used herein to refer to a direction along the tubing string or component towards the surface. Similarly, the terms “bottom” or “downhole” may be used herein to refer to a direction along the tubing string or component towards the bottom of the well, i.e., away from the surface. As would be known to persons skilled in the art, the “toe” of a well is the portion furthest away from the top of the well.
The housing 12 is provided with at least one, and preferably a plurality of ports 22 at a predetermined distance along the length thereof. The ports 22 are generally circumferentially spaced over the housing 12, as shown in
As illustrated further in
As mentioned above,
The piston housing 32 and spool valve housing 34 are sealed against the housing 12. In one preferred aspect, the piston housing 32 and spool valve housing 34 are provided with at least two circumferential grooves generally at the opposite ends thereof.
As illustrated in
As noted above, the sliding sleeve 54 is slidably provided on the valve 10, with the sleeve initially retained in the position shown in
The operation of the subject toe valve will now be described in reference to the figures contained herein.
As described below, the toe valve 10 described herein generally has four states, each of which is briefly summarized below and explained in further detail later in this description. The valve is in its initial state when it, along with the casing, is run into the wellbore. In this state, the ports 22, through which a perforating fluid is ultimately passed, are closed and sealed by the sliding sleeve 54. Once the casing, including the valve 10, is located in the wellbore, the casing is cemented in place, using procedures known in the art. In short, and as described above, cement is provided through the casing and allowed to flow exit the casing and return to surface through the annular space between the casing and the wellbore. During this cementing step, the valve is retained in its initial state.
Once the cementing operation is completed, a pressure test is conducted on the cemented casing as known in the art. As noted, for a pressure test, the interior of the casing, which includes the toe valve 10, is pressurized after sealing the toe of the casing, and the pressure monitored for changes over a given time. Upon pressurizing the casing, the toe valve 10 is actuated to its pressure test state. In this state, the pressure used for the casing integrity test is translated to a force for compressing, or energizing, the spring or biasing element 30 (as discussed further below). The valve 10 is retained in this state while the casing test is conducted. After the test, and as the pressure in the casing is reduced, the biasing element 30 acts on the piston housing 32 to shift or actuate the spool valve 38. The toe valve 10 then enters its third, or activated state. Finally, when the perforation operation is to commence, pressure in the casing, and thus the lumen of the valve 10, is once again increased using a pressurized fluid to cause shifting of the sliding sleeve 54, thereby placing the valve in its final or actuated state. In this state, the ports 22 of the valve 10 are opened and the pressurized fluid is ejected out of the ports and against the adjacent cement. The fluid is thus used to perforate the cement as known in the art. It will be understood that the applied pressure would also dislodge the barrier plugs 24 covering the ports 22.
As noted above,
The operation of the toe valve will now be described in more detail with reference to the accompanying figures.
State 1—Initial State of Toe Valve
As mentioned above, the sleeve 54 is retained in this initial position by a locking means, such as a retaining ring 60 or the like. As will be understood, the retaining ring 60 serves to prevent axial movement of the sleeve within the valve 10.
The sleeve 54 is sealed against the first end 28 of the bottom sub 16 by one or more seals 64, such as O-rings. The sleeve 54 is also sealed against the nose coupling 50 by means of one or more seals, such as O-rings 66. As mentioned above, the sleeve 54 is further sealed against the body housing 12 by means of seals 68 and 70 provided on opposite ends of the region where the ports 22 are located. As will be understood, in this initial state, a sealed annular space is formed, bounded by the region of the body housing 12 having the ports 22, the sleeve 54 and the seals 68 and 70 and seals 64 and 66. In this way, the ports 22 are not exposed to any pressure variations in the lumen of the valve 10 and no fluids are able to pass from the casing through the ports 22.
As also shown in
State 2—Pressure Test
It should be noted that, in states 1 and 2, both ends of the spool valve 38 are subjected to the same pressure. Therefore, in this pressure balanced state, the spool valve 38 is not actuated. This is shown in more detail in
As shown in
As noted above, the check valve 40 only permits transmission of pressurized fluid in the uphole direction. In other words, once the pressurized fluid passes through the check valve 40 and advances, or actuates, the piston pins 36, such pressure is maintained on the piston pins 36, whereby the compressive force on the biasing element 30 is also maintained. In this way, the force exerted on the piston pins 36 by the pressurized fluid is stored in the energized biasing element 30.
State 3—Activation of the Toe Valve
Once the casing pressure test is completed, the pressure within the casing is reduced. This state of the toe valve is illustrated in
It will be understood that the shear pin 82 will be selected according to the anticipated pressure differential established between the annular spaces 74 and 76. Thus, the shear pin 82 serves to retain the spool 78 in its initial state until such time as a predetermined pressure differential is created between the two annular spaces 74 and 76.
As mentioned above, axial advancement, or shifting, of the spool 78 in the downhole directly is limited by the shoulder 130 (as shown in
State 4—Actuation of the Toe Valve
As will be understood, once the toe valve 10 is in the activated state, i.e., state 3, it is in a state that would allow opening of the ports 22 once the sliding sleeve 54 is laterally shifted in the downhole direction from its initial position as shown in
Once the casing is pressurized, the pressurized fluid enters the first annular space 74 through the port 47 and subsequently to the third annular space 88 through the spool valve 38. In other words, the pressurized fluid applied within the casing enters the first annular space 74 and, thereby, the spool port 120. The fluid then passes through the spool 78, and through the aligned ports 80 and 86, and ultimately into the third annular space 88, which is in fluid communication with the sliding sleeve 54. Upon application of a predetermined pressure, the shear ring 60 retaining the sliding sleeve 54 is sheared and the sliding sleeve 54 is thereby axially advanced in the downhole direction into the sleeve receiving annular space 62. As shown in
As will be understood, the present description provides, in one aspect, a toe valve that can be deployed on casing prior to a cementing operation and retained in place during a casing pressure test without being actuated. Actuation of the toe valve to conduct a perforation operation utilizing such valve, may then be accomplished after the casing pressure test is completed.
It will be appreciated that, while the present description has been provided in relation to a toe valve, the components mentioned above, and the associated method steps, would be applicable to any valve where the energy provided with an increased pressure is mechanically stored or retained and used to actuate a component thereof.
Although the above description includes reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art. Any examples provided herein are included solely for the purpose of illustration and are not intended to be limiting in any way. Any drawings provided herein are solely for the purpose of illustrating various aspects of the description and are not intended to be drawn to scale or to be limiting in any way. The scope of the claims appended hereto should not be limited by the preferred embodiments set forth in the above description but should be given the broadest interpretation consistent with the present specification as a whole. The disclosures of all prior art recited herein are incorporated herein by reference in their entirety.
Claims
1. A tool for deployment in a wellbore for performing a perforation step, the tool comprising a generally tubular structure adapted to be assembled on a tubular string, wherein the tool comprises:
- a top sub, adapted to be connected to an uphole tubular component, and a bottom sub, adapted to be connected to a downhole tubular component;
- a tubular housing extending between the top sub and the bottom sub, the tubular housing having a first end connected to the top sub and a second end connected to the bottom sub, and a wall with at least one perforation port for fluid communication through the wall;
- a slidable sleeve provided within the tubular housing, the sliding sleeve being axially moveable with respect to the housing between a closed position, wherein the sleeve covers the at least one perforation port, and an open position, wherein the at least one perforation port is exposed allowing fluid communication through the wall of the tubular housing;
- the top sub including a plurality of pistons, wherein each piston comprises a respective first end and second end;
- the top sub including a biasing means for applying an axial force against the first ends of the pistons;
- at least one first valve adapted to permit pressurized fluid within the lumen of the tool to impinge on the second ends of the pistons and energize the biasing means; and,
- at least one second valve adapted to be actuated by the energized biasing means, whereby, upon actuation, the second valve provides a fluid channel between the lumen of the tool and the slidable sleeve.
2. The tool of claim 1, wherein the sliding sleeve comprises a cylindrical body coaxially provided within the tubular body.
3. The tool of claim 1 further comprising a means of retaining the sliding sleeve in the closed position.
4. The tool of claim 1, wherein the sliding sleeve includes a plurality of seals to prevent flow of fluid there-around when in the closed position.
5. The tool of claim 1, wherein the pistons are circumferentially spaced apart.
6. The tool of claim 5, wherein the pistons are provided within a piston housing connected to the top sub.
7. The tool of claim 6, wherein the piston housing comprises a generally cylindrical body having a plurality of barrels for housing the pistons, wherein the second ends of the pistons are contained within respective apertures.
8. The tool of claim 1, wherein the top sub includes at least one actuation port for transferring pressurized fluid from the lumen of the tool to the second ends of the pistons.
9. The tool of claim 8, wherein the at least one actuation port is provided with a burst plug.
10. The tool of claim 1, wherein the at least one first valve is a check valve.
11. The tool of claim 1, wherein the at least one second valve is a spool valve.
12. The tool of claim 1, wherein the biasing means comprises a spring.
13. The tool of claim 12, wherein the spring comprises a wave spring or a labyrinth spring.
14. A method of operating a tool deployed in a wellbore, the tool comprising a generally tubular structure adapted to be assembled on a tubular string, the tool comprising:
- a top sub, adapted to be connected to an uphole tubular component, and a bottom sub, adapted to be connected to a downhole tubular component;
- a tubular housing extending between the top sub and the bottom sub, the tubular housing having a wall with at least one port for fluid communication through the wall;
- the housing including a slidable sleeve, wherein the sleeve is axially moveable between a closed position covering the at least one port, and an open position, wherein the at least one port is exposed allowing fluid communication through the wall of the tubular housing;
- the top sub including a biasing means;
- the method comprising: pressurizing the lumen of the tool with a fluid under a first pressure and actuating a first valve to permit the fluid to energize the biasing means; reducing the pressure within the lumen of the tool and actuating a second valve to permit fluid within the lumen to impinge on the sliding sleeve; pressurizing the lumen of the tool with a fluid under a second pressure to axially shift the sliding sleeve from the closed position to the open position; and, pressurizing the lumen of the tool with a pressurized fluid to force the pressurized fluid through the at least one port provided on the housing.
15. The method of claim 14, wherein energizing the biasing means comprises compressing a spring.
16. The method of claim 14, further comprising conducting a perforation operation by ejecting a pressurized fluid through the ports.
Type: Application
Filed: Jul 26, 2022
Publication Date: Jan 26, 2023
Applicant: Tryton Tool Services Limited Partnership (Edmonton, AB)
Inventors: Tyler LINDSTRAND (Edmonton), Randy BERRYMAN (Edmonton)
Application Number: 17/815,038