Patent Grant
11454090
This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an example described below, more particularly provides for pressure containment in a chemical treatment well tool assembly.
Subterranean oil and gas wells are subject to problems with corrosion, paraffin, scale, H2S and other conditions that hinder optimum production. These conditions can cause deterioration of pumps, tubing, sucker rods, casing and other components that comprise the equipment that enable production of hydrocarbons to the surface.
In an example described more fully below, a method for alleviating such conditions (or other conditions) includes the use of a downhole chemical treatment assembly. The assembly can contain water soluble solid chemical blends and is preferably installed in a wellbore prior to production of fluids from a well. Fluids could be produced from the well before a particular assembly is installed.
Produced wellbore fluids come into contact with the solid chemical treatment through openings in the assembly. The solid chemical treatment liquifies as it is exposed to fluid and is slowly dispersed within the wellbore, thereby mixing with and treating the produced fluids.
The dispersion of chemical may be regulated by sections of welded wire screen which cover openings in the assembly. A single assembly or “stacked” multiple assemblies may be installed, depending on well conditions, production numbers and severity of well problems.
On occasion, well completions are pulled for repair or maintenance. When pulled, a downhole chemical treatment assembly may still be relatively full of solid chemical treatment, or flow through the screens could be blocked or restricted. In such cases, pressure may be trapped in the assembly when it is retrieved to surface.
Using the principles of this disclosure, the possibility for fluids and/or solid chemical to be forcibly ejected from the assembly as one section is disconnected from another section of the downhole chemical treatment assembly is reduced or eliminated. This enhances the safety of personnel in the vicinity and reduces potential harm to the environment.
An example of a pressure containment valve for a downhole chemical treatment assembly depicted in the accompanying drawings prevents the release of pressure when one section of the assembly is disconnected from another section. The pressure containment valve is spring-loaded and is positioned within box and pin (female and male, respectively) connectors of the assembly. As sections of the assembly are connected together, opposing valve shafts are pressed together, which opens the valves, thereby allowing communication between interior flow passages of the downhole chemical treatment assembly sections.
When the connectors are disconnected, the shafts pull away from each other, causing the valves to close. In single section installations, the valve stays closed and continues to isolate any pressure. The section(s) may then be brought to a refurbishing facility where the pressure is released under safe, controlled conditions.
The pressure containment valves may be used with 2⅜″, 2⅞″, 3⅛″ or 4½″ (or any other) outside diameter tools. In the example depicted in the drawings, the pressure containment valves are housed within a socketed collar and a socketed pin which are welded to outer housings of the downhole chemical treatment assembly.
The example pressure containment valve includes a valve closure, valve seat, valve seat retaining snap ring, valve spring, spring retainer and retainer pin. The valve seat retaining snap ring holds the valve seat in position, and the spring retainer and retainer pin hold the spring in place. A shaft of the valve closure has a selected length to engage with an opposing pressure containment valve's closure shaft.
As connectors are screwed together, in this example, the shafts of the pressure containment valves contact each other and push the valve closures away from the seats, thereby opening the valves. When the connectors are disconnected, the shafts separate, and the springs cause the valve closures to close against the valve seats.
In a single section configuration, the upper connector includes a socketed collar with a no-flow nipple attached. The lower connector includes a socketed collar connected to a bull plug. The socketed collar contains an internal plug which prevents any chemical treatment from falling out of the downhole chemical treatment assembly if the bull plug is removed.
In a two section downhole chemical treatment assembly, the upper connector of an upper section includes a socketed collar with a no-flow nipple. The lower connector of the upper section includes a socketed pin with a pressure containment valve. The upper connector of the lower section includes a socketed collar with a pressure containment valve, and the lower connector includes a socketed collar with an internal plug and a bull plug secured therein.
In a three or more section downhole chemical treatment assembly, the upper connector of the upper section includes a socketed collar with a no-flow nipple. The lower connector of the upper section includes a socketed pin with a pressure containment valve. The upper connector of each intermediate section includes a socketed collar with a pressure containment valve. The lower connector of each intermediate section includes a socketed pin with a pressure containment valve. The upper connector of the lower section includes a socketed collar with a pressure containment valve, and the lower connector includes a socketed collar with an internal plug and a bull plug secured therein.
When the valve shafts are engaged, and the valve closure is disengaged from the valve seat, the pressure containment valve is open, thereby allowing communication between the downhole chemical treatment assembly sections. This allows the wellbore fluids to interact with the solid chemical treatment within the sections. This communication between the sections provides for uniform dispersion of the chemical treatment as it liquefies over time and is released into the wellbore. When the well completion is pulled for repair or due to failure, and the individual sections of the downhole chemical treatment assemblies are disconnected from each other, any pressure which has accumulated within them is contained.
Once the sections are out of the well and disconnected from each other, they may be taken to a refurbishing facility that is equipped with appropriate apparatus to relieve the pressure inside the sections. The apparatus may include a cowl that is lowered over end(s) of the section containing the pressure. A mechanical, hydraulic or pneumatic plunger mechanism may then be used to depress the shaft of the valve closure, thereby allowing pressure inside the section to be released. Any expelled material is directed by the cowl into a container for disposal.
Once pressure has been relieved, the valve seat retaining ring can be removed, thereby allowing the valve seat, valve closure, retainer pin, valve spring and spring retainer, to be removed. This will also allow removal of any remaining chemical treatment remaining inside the section.
Representatively illustrated in
In the
In other examples, portions of the wellbore 12 in which the principles of this disclosure are practiced may be uncased or open hole. Although the wellbore 12 is depicted in
A well completion 20 has been installed in the wellbore 12. The completion 20 facilitates production of well fluids 22 (such as, oil, gas, gas condensates, water, etc.) from the well.
As depicted in
This treatment of the fluids 22 can, for example, prevent buildup of paraffins or scale in the tubing string 26, prevent corrosion of the tubing string, mitigate H2S production, etc. The scope of this disclosure is not limited to any particular purpose for treating the fluids 22.
In the
The sections 28, 30, 32 are connected together before or as they are installed with the completion 20 into the well. When or after the completion 20 is retrieved from the well, the sections 28, 30, 32 are disconnected from each other.
Referring additionally now to
The upper connector 34 comprises a “no-flow” nipple 38 that is threaded into a socketed collar 40. A generally tubular outer housing 42 is welded to the collar 40. The nipple 38 blocks off a flow passage 44 that extends longitudinally through the outer housing 42.
The lower connector 36 comprises a socketed pin and is welded to a lower end of the outer housing 42. A pressure containment valve 46 is secured within the lower connector 36. The pressure containment valve 46 permits selective communication with the flow passage 44.
One or more chemical treatments 48 are contained in the flow passage 44 of the outer housing 42. A screen 50 provides for filtered flow between the flow passage 44 and an exterior of the upper section 28. In this manner, the well fluids 22 can enter the flow passage 44, contact the chemical treatments 48, and the treated fluids can return to the exterior of the upper section 28. Thus, the chemical treatment 48 leaches into the produced well fluids 22.
The pressure containment valve 46 is closed, thereby preventing communication with the flow passage 44 through the lower connector 36. However, when the upper section 28 is connected to the intermediate section 30 as described more fully below, the pressure containment valve 46 will be opened.
Referring additionally now to
As depicted in
Note that a screen 50 is not provided on the outer housing 42. However, in other examples one or more screens could be provided, so that communication is permitted between the flow passage 44 and the exterior of the intermediate section 30 through the outer housing 42.
An upper connector 52 is welded to an upper end of the outer housing 42. The upper connector 52 comprises a socketed collar or box connection. A pressure containment valve 46 is secured in the upper connector 52 to provide selective communication with the flow passage 44 through the upper connector.
The pressure containment valves 46 are closed as depicted in
Referring additionally now to
As depicted in
A lower connector 54 is welded to a lower end of the outer housing 42. The lower connector 54 comprises a socketed collar or box connection. A bull plug 56 closes off a lower end of the flow passage 44. A generally disc-shaped internal plug 58 is threaded into the connector 54 and supports the chemical treatments 48 in the flow passage 44.
The pressure containment valve 46 in the upper connector 52 is closed as depicted in
Referring additionally now to
In the
The closure 60 includes a generally disc-shaped body 60a with a sealing surface 60b thereon configured to sealingly engage a sealing surface 62a on the seat 62. A stem 60c extends longitudinally outward from the body 60a of the closure 60.
When the sealing surfaces 60b, 62a are in sealing contact, flow through ports 62b of the seat 62 is prevented. When the sealing surfaces 60b, 62a are spaced apart from each other, flow through the ports 62b is permitted.
The stem 60c extends through a central opening 62c of the seat 62. The spring 64 encircles the stem 60c and is retained in compression between the seat 62 and the spring retainer 66. The retainer pin 68 prevents displacement of the spring retainer 66 relative to the stem 60c.
The spring 64 biases the closure 60 toward sealing engagement with the seat 62. However, if a longitudinal force is exerted against the stem 60c (in a downward direction as viewed in
Referring additionally now to
When the lower and upper connectors 36, 52 are separated (not operatively connected to each other), the pressure containment valves 46 are closed (e.g., as in
However, when the connectors 36, 52 are operatively connected to each other as viewed in
The lower and upper connectors 36, 52 depicted in
When the lower and upper connectors 36, 52 are connected to each other, the valves 46 are displaced longitudinally toward each other (e.g., as a result of threading one connector into the other connector). Note that it is not necessary for connectors to be threaded together in keeping with the principles of this disclosure, since other means may be used to connect the connectors (such as, a breech-lock type of connection, a latch connection, etc.). Thus, the scope of this disclosure is not limited to any particular technique for operatively connecting the connectors 36, 52.
The longitudinal displacement of the valves 46 toward each other also displaces the valve stems 60c toward each other. Eventually, the valve stems 60c contact or abut each other, and continued displacement of the valves 46 toward each other overcomes the biasing forces exerted by the springs 64, thereby causing the bodies 60a to disengage from the seats 62. In this example, the seats 62 continue to displace toward each other after the valve stems 60c have contacted each other and can no longer displace toward each other.
When the lower and upper connectors 36, 52 are disconnected from each other, the valves 46 are displaced longitudinally away from each other (e.g., as a result of unthreading one connector from the other connector). The longitudinal displacement of the valves 46 away each other also displaces the valve seats 62 away from each other. Eventually, the bodies 60a engage the seats 62, since the springs 64 bias the bodies toward the seats. The valve stems 60c will no longer contact or abut each other as the connectors 36, 52 are separated.
Thus, as described above, the valves 46 are open, the flow passages 44 are in communication with each other, flow is permitted through the ports 62b, and the valve closure 60 is not sealingly engaged with the seat 62, when the connectors 36, 52 are operatively connected to each other. The valves 46 are closed, the flow passages 44 are not in communication with each other, flow is prevented through the ports 62b, and the valve closure 60 is sealingly engaged with the seat 62, when the connectors 36, 52 are disconnected from each other.
It may now be fully appreciated that the above disclosure provides significant advancements to the art of constructing and utilizing chemical treatment assemblies for use in wells. In examples described above, connectors 36, 52 of various sections 28, 30, 32 of the chemical treatment assembly 24 can be disconnected from each other, without the flow passages 44 in the sections being placed in communication with the external environment via the connectors.
The above disclosure provides to the art a chemical treatment assembly 24 for use in a subterranean well. In one example, the chemical treatment assembly 24 can comprise: a first section 28, 30, 32 including a first pressure containment valve 46 that selectively permits and prevents fluid communication with a first flow passage 44 in the first section 28, 30, 32, and a second section 28, 30, 32 including a second pressure containment valve 46 that selectively permits and prevents fluid communication with a second flow passage 44 in the second section 28, 30, 32, and in which the first and second pressure containment valves 46 are closed in response to disconnection of the first section from the second section.
The first and second pressure containment valves 46 may be opened in response to connection of the first section to the second section.
Each of the first and second pressure containment valves 46 may comprise a valve closure 60, and the valve closures 60 may disengage from each other in response to disconnection of the first section from the second section.
The first pressure containment valve 46 may be positioned in a first connector 36 of the first section, the second pressure containment valve 46 may be positioned in a second connector 52 of the second section, and the first and second pressure containment valves 46 may be closed in response to longitudinal displacement of the first and second connectors 36, 52 away from each other.
The first pressure containment valve 46 may comprise a first seat 62, the second pressure containment valve 46 may comprise a second seat 62. The first and second pressure containment valves 46 may be closed in response to longitudinal displacement of the first and second seats 62 away from each other.
Each of the first and second pressure containment valves 46 may comprise a valve closure 60, and the valve closures 60 may contact each other in response to connection of the first section to the second section. The first flow passage 44 may be placed in fluid communication with the second flow passage 44 in response to contact between the valve closures 60.
The above disclosure also provides to the art a method of containing pressure in at least first and second sections 28, 30, 32 of a chemical treatment assembly 24. In one example, the method can comprise: installing a first pressure containment valve 46 in the first section of the chemical treatment assembly 24, and installing a second pressure containment valve 46 in the second section of the chemical treatment assembly 24, the first and second pressure containment valves 46 being configured to close in response to disconnecting the first section from the second section.
The step of installing the first pressure containment valve 46 may comprise sealingly engaging a first valve closure 60 of the first pressure containment valve 46 with a first valve seat 62 of the first pressure containment valve 46, the first pressure containment valve 46 being configured to open in response to relative displacement between the first valve closure 60 and the first valve seat 62.
The step of installing the second pressure containment valve 46 may comprise sealingly engaging a second valve closure 60 of the second pressure containment valve 46 with a second valve seat 62 of the second pressure containment valve 46, the second pressure containment valve 46 being configured to open in response to relative displacement between the second valve closure 60 and the second valve seat 62.
The disconnecting step may comprise displacing the first and second valve seats 62 away from each other. The disconnecting step may comprise preventing flow through ports 62b formed in each of the first and second valve seats 62.
The first and second pressure containment valves 46 may be configured to open in response to connecting the first section to the second section.
The connecting step may comprise displacing the first and second valve seats 62 toward each other. The connecting step may comprise permitting flow through ports 62b formed in each of the first and second valve seats 62.
Also described above is a chemical treatment assembly 24 for use in a subterranean well, the chemical treatment assembly comprising: an outer housing 42, a flow passage 44 extending longitudinally through the outer housing 42, a chemical treatment 48 positioned in the flow passage 44, and a pressure containment valve 46 that selectively permits and prevents fluid communication with the flow passage 44 through the pressure containment valve 46.
The pressure containment valve 46 may be positioned in a connector 36, 52 secured to the outer housing 42. The pressure containment valve 46 may comprise a valve closure 60 that is biased toward sealing engagement with a valve seat 62.
A valve spring 64 may bias the valve closure 60 toward the valve seat 62. The valve spring 64 may bias the valve closure 60 longitudinally away from the flow passage 44.
The valve closure 60 may comprise a valve stem 60c that extends longitudinally outward relative to the outer housing 42. The valve stem 60c may extend longitudinally outward relative to the flow passage 44.
Ports 62b may be formed through the valve seat 62. Sealing engagement between the valve closure 60 and the valve seat 62 may prevent fluid communication between the flow passage 44 and the ports 62b.
Although various examples have been described above, with each example having certain features, it should be understood that it is not necessary for a particular feature of one example to be used exclusively with that example. Instead, any of the features described above and/or depicted in the drawings can be combined with any of the examples, in addition to or in substitution for any of the other features of those examples. One example's features are not mutually exclusive to another example's features. Instead, the scope of this disclosure encompasses any combination of any of the features.
Although each example described above includes a certain combination of features, it should be understood that it is not necessary for all features of an example to be used. Instead, any of the features described above can be used, without any other particular feature or features also being used.
It should be understood that the various embodiments described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of this disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which is not limited to any specific details of these embodiments.
In the above description of the representative examples, directional terms (such as “above,” “below,” “upper,” “lower,” “upward,” “downward,” etc.) are used for convenience in referring to the accompanying drawings. However, it should be clearly understood that the scope of this disclosure is not limited to any particular directions described herein.
The terms “including,” “includes,” “comprising,” “comprises,” and similar terms are used in a non-limiting sense in this specification. For example, if a system, method, apparatus, device, etc., is described as “including” a certain feature or element, the system, method, apparatus, device, etc., can include that feature or element, and can also include other features or elements. Similarly, the term “comprises” is considered to mean “comprises, but is not limited to.”
Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the disclosure, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of this disclosure. For example, structures disclosed as being separately formed can, in other examples, be integrally formed and vice versa. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the invention being limited solely by the appended claims and their equivalents.
| Number | Name | Date | Kind |
|---|---|---|---|
| 339809 | Putman | Apr 1886 | A |
| 2453741 | Bopp | Nov 1948 | A |
| 2512999 | Bruning | Jun 1950 | A |
| 2548528 | Hansen | Apr 1951 | A |
| 2642139 | Bedford | Jun 1953 | A |
| 3994317 | Miyazaki et al. | Nov 1976 | A |
| 4819692 | Olson | Apr 1989 | A |
| 5388874 | Barrier | Feb 1995 | A |
| 5829480 | Smith, III | Nov 1998 | A |
| 5893391 | Jenski, Jr. | Apr 1999 | A |
| 5899228 | Smith, III | May 1999 | A |
| 6206040 | Smith, III | Mar 2001 | B1 |
| 6808023 | Smith et al. | Oct 2004 | B2 |
| 8622085 | June | Jan 2014 | B2 |
| 8857520 | Hoffman et al. | Oct 2014 | B2 |
| 9611949 | Pelfrey | Apr 2017 | B2 |
| 9909703 | Van Scyoc | Mar 2018 | B2 |
| 20150292638 | Pelfrey | Oct 2015 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20200248532 A1 | Aug 2020 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62800963 | Feb 2019 | US |
