The present disclosure is related to wellbore servicing tools used in the oil and gas industry and, more particularly, to an improved coupling for cement heads.
During completion of oil and gas wells, cement is often used to solidify a well casing within the newly drilled wellbore. To accomplish this, cement slurry is first pumped through the inner bore of the well casing and either out its distal end or through one or more ports defined in the well casing at predetermined locations. Cement slurry exits the well casing into the annulus formed between the well casing and the wellbore, and is then pumped back up toward the surface within the annulus. Once the cement hardens, it forms a seal between the well casing and the wellbore to protect oil producing zones and non-oil producing zones from contamination. In addition, the cement bonds the casing to the surrounding rock formation, thereby providing support and strength to the casing and also preventing blowouts and protecting the casing from corrosion.
Prior to cementing, the wellbore and the well casing are typically filled with drilling fluid or mud. A cementing plug is then pumped ahead of the cement slurry in order to prevent mixing of the drilling mud already disposed within the wellbore with the cement slurry. When the cementing plug reaches a collar or shoulder stop arranged within the casing at a predetermined location, the hydraulic pressure of the cement slurry ruptures the plug and enables the cement slurry to pass through the plug and then through either the distal end of the casing or the side ports and into the annulus. Subsequently, another cementing plug is pumped down the casing to prevent mixing of the cement slurry with additional drilling mud that will be pumped into the casing following the cement slurry. When the top cementing plug lands on the collar or stop shoulder, the pumping of the cement slurry ceases.
To perform the aforementioned cementing operations, a cement head or cementing head is usually employed. The cement head is arranged at the surface of the wellbore and the cementing plugs are held within the cement head until the cementing operation requires their deployment. The cement head must be able to withstand enormous tensile forces along its entire length attributable to the overall weight of the work string coupled to the cement head and extended into the wellbore. In some cases, the cement head and its various internal connections may be required to bear several million pounds of tensile force.
The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, without departing from the scope of this disclosure.
For a more complete understanding of the present disclosure, and for further details and advantages thereof, reference is now made to the accompanying drawings, wherein:
The present disclosure is related to wellbore servicing tools used in the oil and gas industry and, more particularly, to an improved coupling for cement heads.
The present disclosure provides embodiments of a cement head that maximize or increase its tensile load capabilities within limited clamping space. More specifically, the disclosed embodiments describe cement head couplings that are configured to support high axial loads from the weight of system components. The couplings may be configured with engagement surfaces positioned and oriented to receive an axial load from a bridge in a direction toward a connecting module. Such engagement surfaces serve to accommodate axial loads applied to adjacent modules in opposite directions. The disclosed coupling interfaces include a plurality of shear lugs or protrusions configured to support high axial loads. The shear lugs or protrusions may also be able to accommodate distributions of loads across protrusions that are non-uniform and otherwise provide the capability to support a share of a total load applied on the cement head.
Referring to
The cement head 100 comprises an output module 102, intermediate modules 104, and an input module 106. Each of the output module 102, intermediate modules 104, and input module 106 have a substantially cylindrical outer profile and each lie substantially coaxial with a central axis 128 that extends generally along the length of the cement head 100 and is generally located centrally within cross-sections of the cement head 100 that are taken orthogonal to the central axis 128. Each intermediate module 104 comprises a launch valve 112. The output module 102 comprises a launch port 114 and a launch indicator 116. The output module 102 further comprises a lower work string interface 108. The input module 106 comprises an upper work string interface 110 and/or one or more mixture ports 176.
Referring to
The output module 102, intermediate modules 104, and input module 106 comprise primary outer profiles 130 (shown in
As shown in
Referring now to
As previously discussed, the bridges 118 further comprise first and second complementary profiles 132 (shown as profiles 132a and 132b). The complementary profiles 132a and 132b comprise complementary protrusions 156a and 156b, respectively. The complementary protrusions 156a and 156b extend radially toward the central axis 128 and are longitudinally offset from each other along the central axis 128. More specifically, the complementary protrusions 156a and 156b are generally shaped as annular rings that, when viewed in a cross-section taken through the central axis 128, appear as polygonal protrusions extending from the inner surface of the bridge 118, toward the central axis 128. Each annular ring provides a ridge that extends at least partly about a circumference at a fixed location. According to some embodiments, the protrusions 156a and 156b follow annular, not helical, paths. Taken together, the complementary protrusions 156a and 156b of the bridge 118 form a series of ridges that are offset longitudinally.
The complementary profiles 132a and complementary protrusions 156a of a bridge 118 are termed such because, at least generally, their shape and size complements the respective primary outer profiles 130a and protrusions 138 of a first module 104 (
Likewise, the complementary profiles 132b and complementary protrusions 156b of a bridge 118 are termed such because, at least generally, their shape and size complements the respective primary outer profiles 130b and protrusions 138b of a second module 104 (
Referring now to
Referring now to
The complementary profiles 132 of the bridge 118 comprise complementary protrusions 156. The complementary protrusions 156 may extend radially toward the central axis 128 and are longitudinally offset from each other along the central axis 128. More specifically, the complementary protrusions 156 may also be shaped as annular rings that, when viewed in a cross-section taken through the central axis 128, appear as protrusions extending from the inner diameter of the bridge 118, toward the central axis 128.
The protrusions 138 and 156 are required to support heavy loads relating to the cement head 100 as well as other wellbore equipment and components. Such loads are transferred between the protrusions 156 of the bridge 118 and the protrusions 138 of the outer profile 130. An aspect of the present disclosure provides enhanced axial support and load distribution.
For example, referring now to
Referring to
As further shown in
According to some embodiments, at least a portion of the support surface 402, engagement surface 404, or top surface 406 is flat, convex, or concave. According to some embodiments, transitions between (i) the support surface 402 and the top surface 406, (ii) the top surface 406 and the engagement surface 404, (iii) the engagement surface 404 and the outer surface 408, or (iv) the outer surface 408 and the support surface 402 are sharp, angular, curved, beveled, smooth, or stepwise.
As further shown in
As further shown in
As further shown in
As further shown in
Engagement of the bridge 118 with the outer profile 130 occurs between contacting pairs of engagement surfaces 404 and 454. Pairs of angles 416 and 466 may be equal yet oblique relative to the central axis 128. Accordingly, pairs of adjacent support surfaces 402 and 452 may be parallel. Pairs of angles 418 and 468 may be equal (e.g., 90°) relative to the central axis 128. Accordingly, pairs of adjacent engagement surfaces 404 and 454 may be parallel. During operation, an axially directed load is transferred between engagement surfaces 404 and 454. In some embodiments, a gap 490 may appear between adjacent top surfaces 406 and 456 and/or between outer surface 408 and inner surface 458. The gap 490 may extend between support surfaces 402 and 452 and have a length 414/464. The retainer 122 may provide a radial or other force to maintain the bridges 118 in engagement with the modules 102, 104, or 106.
According to some embodiments, the support surface 402 of a protrusion 138a and the support surface 452 of a protrusion 156a may at least partially overlap along the axis. Accordingly, the width 410 at the base of the protrusion 138a and the width 460 at the base of the protrusion 156a may partially overlap along the axis. Thus, the same axial length may be utilized by the protrusion 138a and the protrusion 156a to provide a greater width 410 and width 460, respectively. Thus, the sum of the widths 410 and 460 is greater than a combined axial distance from the engagement surface 404 of the protrusion 138a to the engagement surface 454 of the protrusion 138b. At least part of the combined axial distance is occupied by portions of both support surfaces 402 and 452. The load is distributed across greater maximum axial widths 410, 460 than would be provided by rectangular profiles having the same combined axial distance across a pair of rectangular profiles. As such, the protrusions 138a and 156a are able to support greater loads, with less deformation, than would be achieved if the same load were applied to rectangular protrusions occupying the same axial length of space.
As will be appreciated, the increased axial widths 410, 460 and taper of the protrusions 138a, 156a, respectively, effectively increases the shear area over the same length of the bridge 118 as compared with prior designs (e.g.,
According to some embodiments, as shown in
Accordingly, the first and second protrusions 138a,b may have corresponding profiles that differ with respect to orientation of the support surfaces. For example, the first protrusions 138a may have a first profile and the second protrusions 138b have a second profile that is substantially a mirror image of the first profile. The support surfaces of the first protrusions 138a each face in a first direction, having a first axial component. The support surfaces of the second protrusions 138b each face in a second direction, having a second axial component, opposite the first axial component. The respective support surfaces may be non-parallel. Likewise, the respective directions in which the support surfaces face may be non-parallel.
A load transferred by the bridge 118 to each of the modules is received on the corresponding engagement surfaces. The engagement surfaces, having defined orientations and surface areas, are optimized to receive the load. Where each load received by a module 102, 104, 106 is unidirectional, the engagement surfaces are oriented to receive the load and the support surfaces are oriented to support the protrusion while minimizing the space occupied by the protrusion.
The angled support surfaces of the protrusions 138a, 138b, 156a, and 156b provide more shear resistance within a given axial length of the protrusion. Adjacent pairs of protrusions 138a and 156a may overlap at least partially along the axis 128. Likewise, adjacent pairs of protrusions 138b and 156b may overlap at least partially along the axis 128. As such, adjacent pairs of protrusions each provide a greater maximum axial length relative to protrusions with complementary rectangular profile shapes (e.g.,
According to some embodiments, as shown in
It has further been found that, relative to other protrusions, each protrusion along an axial length of a module 102, 104, 106 supports a disproportionate amount of a total load applied to the module 102, 104, 106. It has been found that, for at least some modules, protrusions closer to a source of a load support a greater proportion of the total load. For example, the following percent loads were measured for a module 106 having four protrusions, numbered in order of increasing distance from a set of protrusions of a neighboring module 104 to which the module 106 was coupled:
As shown, the fourth protrusion 138a, closest to the protrusions 138b of a neighboring module 104, received the greatest proportion of the total load. In contrast, the first protrusion 138a, farthest from the protrusions 138b of a neighboring module 104, received the greatest proportion of the total load. According to some embodiments, as shown in
It has further been found that, for at least some modules, a protrusion other than the protrusion closest to a source of a load bears the greatest proportion of the total load. For example, the following percent loads were measured for a module 104 having four protrusions, numbered in order of increasing distance from a set of protrusions of a neighboring module 106 to which the module 104 was coupled:
As shown, the distribution of load shown in Table 2 was more even than in the distribution shown in Table 1. In such cases, the maximum axial widths 410d, 410e, and 410e of the protrusions 138b may still vary according to the load distribution. According to some embodiments, each protrusion has a maximum axial width proportional to its corresponding percent of the total load. Each protrusion 156b of the bridge 118 may have a corresponding and complementary shape and size.
Notably, the protrusions having different maximum axial widths form annular rings. A threaded assembly requires uniform widths to allow threading and intimate engagement of complementary threading patterns. In contrast, embodiments having annular rings that do not follow helical paths may be engaged by a bridge without threading, and thereby allow a diversity of protrusion widths to engage the bridge simultaneously.
As discussed herein, when assembled, exemplary cement heads of the present disclosure are configured to support high axial loads from the weight of system components. The support surfaces of a given module are on axial sides of corresponding protrusions that face toward a connecting module. The engagement surfaces of a given module are on axial sides of corresponding protrusions that face away from the connecting module. Accordingly, the engagement surfaces of each module are positioned to receive an axial load from the bridge in a direction toward the connecting module. Each end of a module receives a unidirectional load, delivered to the engagement surfaces. The bridge provides axial loads to the different modules in opposite directions. Accordingly, the engagement surfaces of the different modules face in opposite directions.
When assembled, the exemplary cement heads of the present disclosure are configured to support high axial loads across a plurality of protrusions. The distribution of loads across protrusions may be non-uniform. Accordingly, the maximum axial width of each protrusion may be different from any other protrusion of the same module. The maximum axial width of each protrusion may be proportional to the corresponding percentage of the total load applied.
It is important to note that while multiple embodiments of a cement head have been disclosed above, each of the cement heads offer a simple method of joining modules together without the need to apply a substantial amount of torque to any of the modules, bridges, or retainers. While the assembly process for each of the above-disclosed embodiments of a cement head may require simple angular orienting about the central axis and/or matching up of modules to be connected, no torque or rotational force beyond the torque necessary to overcome inertial forces related to the modules themselves is necessary to complete the process of connecting adjacent modules. It will further be appreciated that the type of connection between modules described above may also be extended into use for other well service tools and apparatuses. Specifically, equivalents to the primary outer profiles, complementary profiles, bridges, and retainers may be used to join any other suitable tool or apparatus while still achieving the benefits of low or no torque required to make the connection.
To facilitate a better understanding of the present disclosure, the following examples of preferred or representative embodiments are given. In no way should the following examples be read to limit, or to define, the scope of the disclosure.
Embodiments disclosed herein include:
A. A cement head. The cement head includes a first module comprising a first end, a first outer surface, and a plurality of first protrusions extending radially outward from the first outer surface, each of the plurality of first protrusions comprising a first profile in which (i) a first engagement surface faces axially away from the first end and (ii) a first support surface forms a first oblique angle relative to an axis; and a bridge configured to engage the plurality of first protrusions.
B. A method of assembling a cement head. The method includes aligning a first module along an axis, the first module comprising a first end and a first protrusion having a first profile in which (i) a first engagement surface faces axially away from the first end and (ii) a first support surface forms a first oblique angle relative to the axis; and engaging a first complementary surface of a bridge with the first engagement surface.
C. A cement head. The cement head includes a first module comprising a first outer surface and a first plurality of protrusions extending radially outward from the first outer surface, wherein one of the first plurality of protrusions has a maximum axial width different from a maximum axial width of another of the first plurality of protrusions; and a bridge comprising a plurality of inner protrusions configured to engage the first plurality of protrusions wherein one of the plurality of inner protrusions has a maximum axial width different from a maximum axial width of another of the plurality of inner protrusions.
D. A method of assembling a cement head. The method includes aligning a first module along an axis; and engaging a bridge with first protrusions of the first module such that each of the first protrusions receives a corresponding portion of a total axial load via the bridge, and wherein each first outer protrusion has a corresponding maximum axial width proportional to the corresponding portion of the total axial load.
Each of embodiments A, B, C, and D may have one or more of the following additional elements in any combination: Element 1: a second module comprising a second end axially adjacent to the first end of the first module, a second outer surface, and a plurality of second protrusions extending radially outward from the second outer surface, wherein the bridge is further configured to engage the plurality of second protrusions. Element 2: wherein each of the plurality of second protrusions comprises a second profile in which (i) a second engagement surface faces axially away from the second end and (ii) a second support surface forms a second oblique angle relative to the axis. Element 3: wherein the first engagement surface is perpendicular to the first outer surface and wherein the second engagement surface is perpendicular to the second outer surface. Element 4: wherein the first support surface is non-parallel to the second support surface. Element 5: wherein each of the plurality of first protrusions comprises a base at the first outer surface and a top surface disposed (i) axially between the first engagement surface and the first support surface and (ii) radially outward from the first outer surface. Element 6: wherein a maximum axial width of the base is greater than a maximum axial width of the top surface. Element 7: wherein the plurality of first protrusions extend annularly about at least a portion of a circumference of the first module and wherein the plurality of second protrusions extend annularly about at least a portion of a circumference of the second module.
Element 8: aligning a second module along the axis, the second module comprising a second end axially adjacent the first end and a second protrusion having a second profile in which (i) a second engagement surface faces axially away from the second end and (ii) a second support surface forms a second oblique angle relative to the axis; and engaging a second complementary surface of the bridge with the second engagement surface, wherein a load of the first module is transferred to the second module via the bridge. Element 9: a second module comprising a second outer surface and a second plurality of protrusions extending radially outward from the second outer surface, wherein one the second plurality of protrusions has a maximum axial width different from a maximum axial width of another of the second plurality of protrusions, wherein the bridge is further configured to engage the second plurality of protrusions. Element 10: wherein the first plurality of protrusions comprises a first protrusion and a second protrusion disposed between the first protrusion and the second plurality of protrusions and having a maximum axial width greater than a maximum axial width of the first protrusion. Element 11: wherein the second plurality of protrusions comprises a third protrusion and a fourth protrusion, disposed between the third protrusion and the second plurality of protrusions and having a maximum axial width greater than a maximum axial width of the third protrusion. Element 12: wherein the first plurality of protrusions comprises a fifth protrusion between the second protrusion and the second plurality of protrusions, the fifth protrusion having a rectangular profile. Element 13: wherein the second plurality of protrusions comprises a sixth protrusion between the fourth protrusion and the first plurality of protrusions, the sixth protrusion having a rectangular profile. Element 14: wherein the second protrusion is disposed axially between the first protrusion and the second plurality of protrusions and wherein the fourth protrusion is disposed axially between the third protrusion and the first plurality of protrusions. Element 15: wherein each of the plurality of first protrusions comprises a first profile in which a first engagement surface faces axially away from the second module and a first support surface forms an oblique angle relative to the axis. Element 16: wherein each of the plurality of second protrusions comprises a second profile in which a second engagement surface faces axially away from the first module and a second support surface forms an oblique angle relative to the axis.
Element 17: wherein a corresponding portion of the total axial load received by one of the first outer protrusions is different from another corresponding portion of the total axial load received by another of the first outer protrusions. Element 18: wherein a maximum axial width of one of the first outer protrusions is different from another maximum axial width of another of the first outer protrusions. Element 19: aligning a second module along the axis and adjacent to the first module; and engaging the bridge with second protrusions of the second module such that each of the second protrusions receives a corresponding portion of a total axial load via the bridge, and wherein each second outer protrusion has a corresponding maximum axial width proportional to the corresponding portion of the total axial load.
Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.
Filing Document | Filing Date | Country | Kind |
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PCT/US2013/054464 | 8/12/2013 | WO | 00 |