Tree Cap with No-Bolt Connection

Embodiments of the present disclosure relate to connection systems in tree cap arrangements, and in particular, no bolt connections used within tree caps.

Tree caps are pressure-containing barriers installed in oil and gas drilling equipment. Tree caps are part of a Christmas tree (XT) that is installed at above an oil and gas well, and can be installed in surface level or subsea environments. Tree caps are often located at the top of an XT in order to provide access to the well bore and prevent pressure from escaping out of the XT. This can pose many challenges, because it is beneficial to have quick and easy access to the well bore while also having a secure enough seal to contain the pressure therein. Typically, tree caps are secured in place using threaded connections, which increase removal time and assembly time. There is a need in the industry for a tree cap that provides quicker access to the well bore, thereby reducing operation costs.

Applicant recognized the problems noted above herein and conceived and developed embodiments of systems and methods, according to the present disclosure, for tree cap systems.

In an embodiment, a tree cap may include a tree cap body having an open end, a blanking plug positioned adjacent the tree cap body and at least partially received within the open end of the tree cap body, a hold down cap nut in axial alignment with the blanking plug and the tree cap body along a tree cap body axis, the hold down cap nut engaged with the tree cap body and the blanking plug to limit axial movement of the blanking plug relative to the tree cap body, and a quick connection system. The quick connection system may include one or more tree cap body lugs extending radially outward from the tree cap body, the one or more tree cap body lugs arranged in one or more tree cap body lug rows, and one or more cap nut lugs extending radially inward from the hold down cap nut, the one or more cap nut lugs arranged in one or more cap nut lug rows, so that when the one or more tree cap body lugs are circumferentially aligned with the one or more cap nut lugs, interference between the one or more tree cap body lugs and the one or more cap nut lugs limits relative axial movement between the tree cap body and the hold down cap nut.

In another embodiment, a tree cap may include a tree cap body having an open end, a blanking plug, a hold down cap nut in axial alignment with the blanking plug and the tree cap body, the hold down cap nut engaged with the tree cap body and the blanking plug to limit axial movement of the blanking plug relative to the tree cap body, and a quick connection system configured to secure the blanking plug to the tree cap body. The quick connection system may include a tree cap body lug extending radially outward from the tree cap body, a cap nut lug extending radially inward from the hold down cap nut, the cap nut lug at least partially axially aligned with and configured to engage the tree cap body lug to limit relative axial movement between the tree cap body and the hold down cap, and a latch configured to prevent rotational movement of the hold down cap nut relative to the tree cap body.

In another embodiment, an assembly may include a composite block and a tree cap. The tree cap may include a tree cap body having an open end, a blanking plug positioned adjacent the tree cap body and at least partially received within the open end of the tree cap body, a hold down cap nut in axial alignment with the blanking plug and the tree cap body along a tree cap body axis, the hold down cap nut engaged with the tree cap body and the blanking plug to limit axial movement of the blanking plug relative to the tree cap body, and a quick connection system. The quick connection system may include one or more tree cap body lugs extending radially outward from the tree cap body, the one or more tree cap body lugs arranged in one or more tree cap body lug rows, and one or more cap nut lugs extending radially inward from the hold down cap nut, the one or more cap nut lugs arranged in one or more cap nut lug rows, so that when the one or more tree cap body lugs are circumferentially aligned with the one or more cap nut lugs, interference between the one or more tree cap body lugs and the one or more cap nut lugs limited relative axial movement between the tree cap body and the hold down cap nut.

The foregoing aspects, features, and advantages of the present disclosure will be further appreciated when considered with reference to the following description of embodiments and accompanying drawings. In describing the embodiments of the disclosure illustrated in the appended drawings, specific terminology will be used for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms used, and it is to be understood that each specific term includes equivalents that operate in a similar manner to accomplish a similar purpose. Additionally, like reference numerals may be used for like components, but such use should not be interpreted as limiting the disclosure.

When introducing elements of various embodiments of the present disclosure, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and/or environmental conditions are not exclusive of other parameters/conditions of the disclosed embodiments. Additionally, it should be understood that references to “one embodiment”, “an embodiment”, “certain embodiments”, or “other embodiments” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, reference to terms such as “above”, “below”, “upper”, “lower”, “side”, “front”, “back”, or other terms regarding orientation or direction are made with reference to the illustrated embodiments and are not intended to be limiting or exclude other orientations or directions. Like numbers may be used to refer to like elements throughout, but it should be appreciated that using like numbers is for convenience and clarity and not intended to limit embodiments of the present disclosure. Moreover, references to “substantially” or “approximately” or “about” may refer to differences within ranges of +/−10 percent.

Tree caps are typically located at the top of a Christmas tree (XT) in oil and gas applications in order to provide access to the well bore. As typically used in the industry, the lower section of a tree cap usually includes a flanged connection, and the upper section of the tree cap usually includes a threaded connection between the body of the tree cap and the hold down cap nut, in order to keep the blanking plug in place. The threaded connection between the body of the tree cap and the hold down cap nut can cause leaks, be difficult and time consuming to replace, and result in higher operation costs. The threaded connection also may increase assembly time during installation on the XT.

Embodiments of the present disclosure may replace the threaded connection on a tree cap by using a No-bolt connection (e.g. a “quick connection system”). The No-bolt connection may be implemented to secure the hold down cap nut to the body of the tree cap in order to hold the blanking plug in place in the tree cap of an XT. Elimination of the threaded connections and instead employing a No-bolt connection may reduce the time it takes to install the tree cap on an XT, which reduces operation costs during installation. The elimination of the threaded connection may also reduce leaks out of the tree cap. Further, instead of the lower portions of the tree cap having a flange connection, the tree cap with the No-bolt connection may be installed as part of a composite block, thus eliminating a potential leak path. Lastly, since the No-bolt connection is quicker to secure and unsecure than a threaded connection, which has to be screwed in and out, the installation or replacement of a tree cap with a No-bolt may also be faster, which may decrease operation costs.

is an isometric view of an embodiment of a tree cap. Various components have been removed for simplicity with the present discussion, but additional components may be used with the tree cap. The illustrated tree capincludes a tree cap body. The tree capalso includes a hold down cap nut, the hold down cap nutaligned substantially parallel with the tree cap bodyalong the tree cap body axis. The hold down cap nutholds down a blanking plug, the blanking plugaligned substantially parallel with the hold down cap nutand tree cap bodyalong the tree cap body axis. The hold down cap nutholds down the blanking plugusing internal interfaces, which are shown in more detail in.

Additionally, the tree capofincludes a flangeconnected to the tree cap body. It should be appreciated that while the illustrated tree capincludes a flange, it may also include other portions for various type of connections to other equipment. For example, the tree capmay a part of a composite block (not depicted in), instead of having a flange connection. The tree capas part of a composite block is shown in more detail in. In the illustrated tree cap, the flangecontains one or more flange aperturesdesigned to receive fasteners (not depicted). The flangemay be connected with fasteners, through the flange apertures, to other compatible equipment. It should be appreciated that the flangeof the tree capmay be an API top flange as well. Also, the flangemay connect through means other than fasteners, such as via a threaded connection.

The illustrated tree capalso includes lifting eyes, which can be attached to or formed integrally with the blanking plug. The lifting eyesallow the tree capto be lifted and/or moved using external equipment, and serve as a contact point of the tree capfor this external lifting means. It should be appreciated that although there are two lifting eyes illustrated in, there may be any number of lifting eyes, depending on the embodiment. When the hold down cap nutis engaged with the blanking plug, lifting the lifting eyesmay lift the entire tree cap. It should be appreciated that in the illustrated tree cap, the lifting eyesare secured to the blanking plug, which may also offer the benefit of allowing only the blanking plug(and not the other components of the tree cap) to be removed from the tree capwhen the hold down cap nutis not engaged. The internal components of the tree capand the interaction between the hold down cap nutand blanking plugare shown in more detail in.

Additionally, the tree capincludes a quick connection system, such as the system described in U.S. patent application Ser. No. 16/728,213, titled “No-Bolt Valve Assembly System,” filed Dec. 27, 2019 by Baker Hughes Oilfield Operations LLC, which is hereby incorporated by reference in its entirety. The tree capcan include a latchon the external surface of the hold down cap nut. The latchmay be in an open or a closed position, which may correspond with the quick connection system being engaged or not engaged, respectively. The latchas depicted inis in the closed position, which is characterized by the external surface of the latchbeing substantially flush with the external surface of the hold down cap nut. In other words, when the latchis in a closed position, the latchis not substantially protruding from the side of the hold down cap nut. In the closed position, internal components of the latchof the hold down cap nutengage with internal components of the blanking plug(such internal components are not depicted in, but are shown in detail in). On the other hand, when the latchis in an open position, the external surface of the latchis at an angle oblique to the external surface of the hold down cap nut. In this open position, the latchis protruding from the side of the hold down cap nut. In the open position, internal components of the latchof the hold down cap nutare not engaged with internal components of the blanking plug(such internal components are not depicted in, but are shown in detail in).

Furthermore, the latchmay be connected to the hold down cap nutand secured to the hold down cap nutvia the roll pin. The latchmay be able to open and close by pivoting about the roll pin. The roll pinmay be housed in a roll pin aperture. The roll pinextends through the roll pin apertureand through apertures in the latch(not depicted in). The latchis also connectable to the hold down cap nutvia a spring plunger. In some embodiments, the spring plungermay be connected to, and extend out of, the latch. When the latchis in a closed position, the spring plungerlines up with the spring plunger apertures, a spring mechanism of the spring plungerextends the spring plungeroutwards from the latchinto the spring plunger aperture, and locking the latchin place in the side of the hold down cap nut.

is a cross-sectional view of an embodiment of a tree cap, which shares several similar features with the tree capof, such as the tree cap body, hold down cap nut, latch, and others, which will be identified with like reference numerals for convenience purposes only and not to limit the scope of the present disclosure. As can be seen in the cross-sectional view of, the tree cap body, the hold down cap nut, the blanking plug, and the flangeare aligned substantially parallel along the tree cap body axis. It should be appreciated that although there are two lifting eyes illustrated in, there may be any number of lifting eyes, depending on the embodiment.

Also illustrated inis a cross-sectional view of the latchand embodiments of its features, including the roll pin, roll pin aperture, spring plunger, and spring plunger aperture. The cross-sectional view ofalso shows the internal features of the interaction and interfaces between the tree cap bodyand the hold down cap nut, among other interfaces. Namely, the tree cap bodyhas one or more tree cap body lugs, and the hold down cap nuthas one or more cap nut lugs. Inside of the hold down cap nut, when the hold down cap nutis secured to the tree cap body, the tree cap body lugsof the tree cap bodyand the cap nut lugsof the hold down cap nutform one or more lug interfaces. The lug interfacesare a contact point between the hold down cap nutand the tree cap body. When the hold down cap nutis secured to the tree cap body, meaning the lug interfacesare engaged, it keeps the hold down cap nutsecured to the tree cap bodyand retains downward force on the blanking plug, keeping blanking plugin place.

It should be appreciated that although only one row of tree cap body lugs(a row of tree cap body lugs here defined as tree cap body lugssubstantially circumferentially surrounding the tree cap body axison the tree cap body) is depicted in, there may be any number of tree cap body lugsin the tree cap. Similarly, it should be appreciated that although only one row of cap nut lugs(a row of cap nut lugs here defined as cap nut lugssubstantially circumferentially surrounding the tree cap body axison the hold down cap nut) is depicted in, there may be any number of cap nut lugsin the tree cap. In an embodiment, there is one row of tree cap body lugsand two or more rows of cap nut lugs. In another embodiment, there is one row of cap nut lugsand two or more rows of tree cap body lugs. In another embodiment, there is an equal number of rows of tree cap body lugsas there are rows of cap nut lugs. For example, there may be one row of tree cap body lugsand one row of cap nut lugs(as depicted in), there may be two rows of tree cap body lugsand two rows of cap nut lugs, there may be three rows of tree cap body lugsand three rows of cap nut lugs, etc. Rows of tree cap body lugsmay be arranged on planes perpendicular to the axison the tree cap body. Similarly, rows of cap nut lugsmay be arranged on planes perpendicular to the axison the hold down cap nut. More rows of lugs,may be utilized based on the required yield strength of the lugs,. When there are multiple rows of lugs,, there also may be multiple rows of lug interfaces. When there are multiple rows of tree cap body lugsand cap nut lugs, the spacing between the rows may be dependent on the height of the tree cap body lugsand cap nut lugsthemselves such that the lugs,must be able to rotate around the tree cap body axisupon the engagement and disengagement of the quick connection system. An example embodiment of a tree cap bodywith more than one row of tree cap body lugsis shown in more detail in.

Furthermore, the rows of lugs,may be positioned such that the lugs,are axially aligned or are not axially aligned. For example, the tree cap body lugsin a first row of tree cap body lugsmay be offset or staggered (e.g. not axially aligned) from the tree cap body lugsin a second row of tree cap body lugs. The offset may be beneficial by allowing the hold down cap nutto be better secured to the tree cap bodydue to the staggering of the lugs,in the arrangement. However, offsetting the lugs,between the rows of tree cap body lugsand cap nut lugsmay increase install and replacement time, due to having to twist down the lugs,between each row of lugs,, sequentially. It should also be appreciated thatdepicts a tree capwith internal lugs,, however, the arrangement of the lugs,may be such that the tree cap body lugsand cap nut lugsare on the external surfaces of the tree cap bodyand hold down cap nut, respectively.

The latchalso includes a latch member. In, the memberof the latchis in an engaged position, sincedepicts the latchin a closed position. The memberof the latchbeing in a closed position creates a recess. When the latchis moved to an open position, the recessprovides the physical space for the latchto rotate about the roll pinand protrude outward from the hold down cap nut. One or more hold down interfaces, are created when the hold down cap nutis engaged with the tree cap bodyso that the hold down cap nutholds the blanking plugin place. The hold down interfacesare a contact point between the hold down cap nutand the blanking plug, retaining the blanking plugand ensuring the blanking plugdoes not disengage from the tree cap. Furthermore, the blanking plugmay include a sealcircumscribing the blanking plugin a seal recess. The sealmay be made of rubber, or another suitable material for restricting fluid (e.g. liquid, gas, solid, or a combination thereof) leakage. When the blanking plugand tree cap bodyare joined, the sealengages and seals the interface therebetween. The tree cap bodydefines the tree cap cavitythat is contained internally within the tree cap.

is an isometric view of an embodiment of a quick connection system. The quick connection systemis integrated into a hold down cap nut, as in. Similar to, the quick connection systemincludes a latch, roll pin, roll pin aperture, spring plunger, spring plunger aperture, and latch member. The latchillustrated inis in an open position, whereas the latchinis in a closed position. The open position of the latchmay be defined as the latchprotruding outwards from the hold down cap nutand the latch memberbecoming disengaged.

The spring plungerof the quick connection systemis biased outward, but is depressible. When the latchis in a closed position, the spring plungerextends into the spring plunger apertureto retain the latchin a closed position. When the spring plungeris depressed, the spring plungerdisengages the spring plunger aperture, thereby allowing the latchto move to an open position by rotating about the roll pin.

is a top view of an embodiment of a tree cap, which shares several similar features with the tree capofand tree capof, such as the hold down cap nut, blanking plug, flange, and others, which will be identified with like reference numerals for convenience purposes only and not to limit the scope of the present disclosure. As illustrated in, the blanking plug, hold down cap nut, and flangeare concentric at the tree cap axis. In order to engage or disengage the hold down cap nuton the tree cap body(not depicted in), the hold down cap nutmay be rotated about the tree cap body axisclockwise or counterclockwise relative to the tree cap bodyand flange connection. The rotation of the internal components, not illustrated in, is shown in more detail in. In embodiments in which the hold down cap nutis removed from the tree cap, the blanking plugmay be rotated in a similar manner. Furthermore, it should be appreciated that although eight flange aperturesare depicted in the flange connectionof, there may be any reasonable number of flange aperturesdepending on the configuration of the external equipment that the tree capis to be connected to.

are top plan cross-sectional views of an embodiment of the tree cap, showing the tree cap bodyinterfacing with the hold down cap nutvia the tree cap body lugsand cap nut lugs. In the illustrated embodiment, the tree cap bodyis arranged circumferentially within at least a portion of the hold down cap nut. However, other portions of the tree cap bodymay be outside of the hold down cap nutor substantially aligned with the tree cap body. It should also be appreciated that various components have been removed for clarity with the following discussion.

In the illustrated embodiments of, the cap nut lugsextend radially inward toward the tree cap body axis. The illustrated cap nut lugsare arranged within the gapspositioned between adjacent tree cap body lugs. The tree cap body lugsextend radially outward from the tree cap body axisand are positioned within spacesbetween the cap nut lugs. The arrangement illustrated inenables the axial movement of the tree cap bodyand/or the hold down cap nutalong the tree cap body axis. For example, the tree cap bodymay be moved through the spaceswhen the tree cap body lugspass through the spaces.

In operation, at least one of the hold down cap nutand the tree cap bodymay be rotated to align, at least partially, the tree cap body lugswith the cap nut lugs, as illustrated in. As a result, axial movement between the hold down cap nutand the tree cap bodymay be blocked due to the interference between the tree cap body lugsand the cap nut lugs. In various embodiments, the rotation is less than one full rotation of the hold down cap nutand/or the tree cap body. For example, the rotation can be approximately 10 degrees, approximately 20 degrees, approximately 30 degrees, approximately 40 degrees, approximately 50 degrees, approximately 60 degrees, approximately 70 degrees, approximately 80 degrees, approximately 90 degrees, approximately 100 degrees, approximately 110 degrees, approximately 120 degrees, approximately 130 degrees, approximately 140 degrees, approximately 150 degrees, approximately 160 degrees, approximately 170 degrees, approximately 180 degrees, approximately 190 degrees, approximately 200 degrees, approximately 210 degrees, approximately 220 degrees, approximately 230 degrees, approximately 240 degrees, approximately 250 degrees, approximately 260 degrees, approximately 270 degrees, approximately 280 degrees, approximately 290 degrees, approximately 300 degrees, approximately 310 degrees, approximately 320 degrees, approximately 330 degrees, approximately 340 degrees, approximately 350 degrees, or any other reasonable rotational amount. Moreover, the tree cap body gapsand the hold down cap nut spacesare substantially aligned.

It should be appreciated that while the embodiments illustrated ininclude an equal number of tree cap body lugsand cap nut lugs, that in other embodiments that may not be an equal number. For example, there may be more tree cap body lugsthan cap nut lugs, or vice versa. Furthermore, while the illustrated embodiments include eight tree cap body lugsand eight cap nut lugs, it should be appreciated that there may be any reasonable number of tree cap lugsarranged radially around the tree cap body axison the tree cap body. Similarly, it should be appreciated that there may be any number of cap nut lugsarranged radially around the tree cap body axison the hold down cap nut. Additionally, as is depicted in, the tree cap body lugsmay be arranged with equal spacing between each tree cap body lug, and the cap nut lugsmay be arranged with equal spacing between each cap nut lug.

In an embodiment, a method of assembling the tree capmay first include positioning the hold down cap nutin alignment with the tree cap bodyalong the tree cap body axis. The method may include aligning the tree cap body lugswith the hold down cap nut spaces, and/or aligning the hold down cap nut lugswith the tree cap body gaps. Once the lugs,are aligned with the spacesand/or gaps, as applicable, the tree cap bodymay be moved towards the hold down cap nutsuch that the hold down cap nutmay at least partially surround the tree cap body. Once the tree cap body lugspass through the hold down cap nut spacesand/or the hold down cap nut lugspass through the tree cap body gaps, the method may include the hold down cap nutbeing rotated, at least partially, relative to the tree cap body, to an engaged position. The engaged position, an example embodiment of which is depicted in, is defined as the tree cap body lugshaving passed through the hold down cap nut spacesand/or the hold down cap nut lugshaving passed through the tree cap body gaps, with tree cap body lugsbeing at least partially vertically aligned with the hold down cap nut lugs, along the valve body axis. In an embodiment, a method of disassembling the tree capmay begin with the engaged position, and positioning the tree cap body lugsto align with the hold down cap nut spacesand/or the hold down cap nut lugsto align with the tree cap body gaps, then moving the hold down cap nutapart from the tree cap bodyalong the valve body axis.

is a partial cross-sectional internal side view of an embodiment of a tree cap, which shares several similar features with the tree capof, the tree capof, the tree capof, such as the tree cap body, hold down cap nut, flange connection, tree cap body lugs, and others, which will be identified with like reference numerals for convenience purposes only and not to limit the scope of the present disclosure. As shown in, the tree cap body lugsare arranged in a single row of tree cap body lugs, with gapsbetween each of the tree cap body lugs. There is a partial cutaway in the hold down cap nutdepicted in, but one cap nut lugis shown. In, the tree cap body lugis partially engaged with an associated cap nut lug. In this configuration, axial movement of the hold down cap nutrelative to the tree cap body, along the tree cap body axis, is inhibited because the lugs,block upwards and downwards axial movement due to the engagement of the lugs,.

is a side view of an embodiment of a tree cap integrated into a composite block assembly. The composite block assemblyincludes a tree cap, which shares several similar features with the tree capof, tree capof, the tree capof, and the tree capof, such as the tree cap body, hold down cap nut, latch, and others, which will be identified with like reference numerals for convenience purposes only and not to limit the scope of the present disclosure. The tree cap, instead of having a flange connection(not depicted in), is part of the composite block assembly, which includes a composite block. The composite blockmay be integrated into an XT assembly (not depicted). One benefit of the tree capintegrated into the composite block assemblyis that it eliminates a potential leak path through the flange connection.

The composite blockofincludes one or more XT valve connectionsthat may be used when the composite blockis integrated into an XT. It should be appreciated that four XT valve connectionsare depicted in the composite block assembly, however, there may be any reasonable number of XT valve connectionsbased on the design of the composite blockand any external XT equipment. Additionally, the composite blockmay be different sizes relative to the tree cap, andmay not be drawn to scale. Furthermore, the composite blockitself may have one or more block flange connectionsfor connection to other external equipment, such as equipment integrated into an XT. Similarly,depicts one block flange connection, however, there may be any reasonable number of block flange connectionsbased on the design of the composite blockand any external XT equipment.

is a side view of an embodiment of a quick connection systemthat is in an open position. The quick connection systemis integrated into a hold down cap nut, as in. Similar to, the quick connection systemincludes a latch, roll pin, roll pin aperture, spring plunger aperture, and latch member. The view ofshows the interaction between the latch memberand one or more tree cap body lugs, within the quick connection system. When moving the latchinto a closed position, the latch membermay fit between tree cap body lugs, which may prevent rotational movement of the hold down cap nutrelative to the tree cap body. When rotational movement is applied to the hold down cap nutrelative to the tree cap body, the latch membermay engage one or more tree cap body lugsto prevent the rotational movement.

is a schematic side view of a tree cap. The illustrated tree capincludes a tree cap body, but a hold down cap nutis not depicted. The tree capalso includes the tree cap body axisand the flange connection. Notably,is an example embodiment of multiple rows of tree cap body lugs. One or more first tree cap body lugsare arranged into a first row of tree cap body lugs, the one or more first tree cap body lugsaligned in a plane around the circumference of the tree cap bodydefining the first row. One or more second tree cap body lugsare arranged into a second row of tree cap body lugs, the one or more second tree cap body lugsaligned in a plane around the circumference of the tree cap bodydefining the second row. As can be seen, the first tree cap body lugsare not circumferentially aligned with the second tree cap body lugs, thus creating an “offset” configuration between the first rowand second rowof lugs,. However, it should be appreciated that the first and second tree cap body lugs,do not need to be in an offset configuration, and may instead be circumferentially aligned with each other. Additionally, although cap nut lugson a hold down cap nutare not depicted in, a similar configuration may be possible with first and second cap nut lugs on a first and second row on the hold down cap nut, both in an offset configuration and a configuration where the first and second cap nut lugs are aligned circumferentially.

Although the technology herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present technology. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present technology as defined by the appended claims.