This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in one example described below, more particularly provides a rotating control device with a latch that is biased toward engagement.
A rotating control device (RCD, also known as a rotating head, rotating blowout preventer and rotating diverter) is used to seal off an annulus about a rotatable tubular (such as, part of a drill string or other tubular string) at or near the earth's surface. For this purpose, the rotating control device includes an annular seal, which may rotate with the tubular. If the annular seal does rotate, bearings can be used to allow the seal to rotate relative to an outer housing of the rotating control device.
It is beneficial to be able to releasably latch the seal and/or bearings relative to the outer housing, so that the seal and/or bearings can be conveniently installed and removed when desired. Thus, it will be appreciated that improvements are continually needed in the arts of constructing and operating latches for rotating control devices.
In the
The BOP stack 14 can be connected to various types of structures (for example, a tensioner ring of a riser string, a wellhead or a lower marine riser package (LMRP)), so that the passage 16 is in communication with a wellbore (not shown). However, the scope of this disclosure is not limited to use of the RCD 12 with any particular type of drilling rig, or to any particular arrangement or configuration of components or well tools above or below the RCD.
The RCD 12 in this embodiment includes a seal and bearing assembly 30 (alternatively referred to as the “assembly” with respect to this embodiment). In particular, the assembly 30 in this embodiment includes both an annular seal component for sealing with an inserted tubular member and a bearing component for facilitating rotation of the annular seal with respect to the RCD 12. In another embodiment, the seal component and bearing component could be separable, such that either or both of the seal component and bearing component could be separately secured to a housing of an RCD according to the principles disclosed herein. In yet another embodiment, the bearing component could be omitted, such that only a seal assembly could be releasably secured to the housing of the RCD. The RCD 12 in this embodiment further includes a latch 24 for releasably securing the seal and bearing assembly 30 in an outer housing 26 of the RCD. In
The engagement members 28 of
The assembly 30 includes bearings 36, which permit the seal 32 to rotate relative to the outer housing 26. In this manner, the seal 32 can rotate with the tubular 34 while sealing off an annular space 38 formed radially between the tubular and the outer housing 26.
In the
In other examples, an assembly latched into the outer housing 26 could comprise a protective sleeve (not shown) for protecting seal bores, shoulders and other structures in the outer housing 26. Thus, it is not necessary for an assembly latched into the outer housing 26 to include an annular seal and/or a bearing.
One seal 32 is depicted in
As described more fully below, the latch engagement members 28 can be displaced radially relative to the outer housing 26 between a position in which removal of the seal and bearing assembly 30 from the RCD 12 is prevented (as in
The seals 40 longitudinally straddle the engagement members 28. In this manner, well fluids and debris are effectively isolated from the engagement member 28 while the seal and bearing assembly 30 is positioned in the housing 26, thereby preventing such well fluids and debris from hindering displacement of the engagement member.
A piston 44 of the latch 24 is displaced upwardly, in order to displace the engagement member 28 radially inward. In other examples, the piston 44 could be displaced downwardly to displace the engagement member 28 inward. Thus, the scope of this disclosure is not limited to any particular configuration or direction of displacement of any components of the latch 24.
In the
A biasing device 20 (such as, a coiled spring, wave springs or Bellville washers) continually biases the piston 44 upward so that, unless increased pressure is applied to the port 48, a net upward biasing force is applied to the piston. In this manner, the piston 44 maintains the engagement member 28 in its inwardly displaced, latched position, unless increased pressure is applied to the port 48. In
When the piston 44 displaces upward (due to the biasing force exerted by the biasing device 20), rollers 22 carried on a rod 18 connected to the piston and received in a lateral slot 82 in the engagement member 28 urge the engagement member 28 to displace longitudinally upward and radially inward along an inclined face 80 formed in an upper section 26a of the outer housing 26 to the latched position of
As a contingency measure, or if pressure is not available for applying to the port 48, the piston 44 can be displaced downward by threading a threaded member 60 (such as, an internally threaded nut) onto a lower end of the piston. Threaded engagement between the piston and the threaded member 60 will cause the piston to be biased downward by rotation of the threaded member. Note that it is not necessary for the member 60 to be internally threaded. In other examples, the threaded member 60 could be externally threaded and the piston 44 could be internally threaded, or the piston could be otherwise manually displaced to its downward unlatched position.
Referring again to
Thus, it is not necessary to maintain increased pressure at the port 46 in order to maintain the engagement member 28 engaged in the recess 42, whether or not the assembly is biased upward, such as, by increased pressure in the annular space 38. The biasing force exerted by the biasing device 20 is sufficient to keep the engagement member 28 from displacing longitudinally downward and radially outward due to the force of gravity acting on the engagement member when there is no upwardly biasing force applied to the assembly 30.
However, it should be understood that it is not necessary for the inclined faces 80, 84 to be parallel to each other. Materials, surface finishes and resulting coefficients of friction for the inclined faces 80, 84 and the engagement member 28 can be selected, and appropriate angles of inclination can be selected, so that, even if the inclined faces are not parallel, the engagement member will not displace radially outward, no matter how much upwardly biasing force is applied to the assembly 30.
In this example, the biasing device 20 and the piston 44 are components of an actuator 86 of the latch 24. The actuator 86 also includes the ports 46, 48 and a sleeve 88 in which the piston 44 is sealingly and reciprocably received.
In examples described herein, there is one actuator 86 for each engagement member 28. However, in other examples, a single actuator 86 could be used to displace multiple engagement members 28, or multiple actuators could be used to displace a single engagement member. Thus, the scope of this disclosure is not limited to any particular configuration, arrangement or number of actuators 86 relative to engagement members 28.
Note that, when the piston 44 displaces upwardly, the rollers 22 contact an upper side 82a of the slot 82 to thereby positively displace the engagement member 28 radially inward (and longitudinally upward). Furthermore, when the piston 44 displaces downwardly, the rollers 22 contact a lower side 82b of the slot 82 to thereby positively displace the engagement member 28 radially outward (and longitudinally downward). Thus, a possibility of the engagement member 28 sticking or jamming in its latched or unlatched positions is significantly reduced, since the engagement member is positively displaced from one position to the other.
Before the assembly 30 is installed in the outer housing 26, the engagement members 28 are in their radially inward latched positions, due to the biasing force exerted by the biasing device 20 maintaining the piston 44 in its upper position. When the assembly 30 is inserted downwardly into the housing 26, a lower inclined shoulder 90 formed on the assembly will eventually contact an upper inclined face 92 on the engagement member 28. Further downward displacement of the assembly 30 will cause the shoulder 90 to urge the engagement member 28 radially outward, and the assembly can then be displaced further downward to its operative position.
When the engagement member 28 is laterally aligned with the recess 42, the engagement member can displace radially inward into engagement with the recess, due to the biasing force exerted by the biasing device 20. Thus, the assembly 30 can be securely latched into the housing 26, without applying any pressure to the actuator 86.
In some instances, increased pressure could be applied to the port 46 after the assembly 30 has been latched into the housing 26, in order to ensure that the engagement members 28 are fully engaged with the recess 42. Furthermore, in some examples, increased pressure could be applied to the port 48 prior to inserting the assembly 30 into the housing 26, in order to radially outwardly displace the engagement members 28, so that they do not contact the assembly as it is being installed into the housing. In these examples, the increased pressure applied to the port 48 would be relieved after the assembly 30 is in its operative position with the engagement members 28 aligned with the recess 42. When the increased pressure is relieved, the biasing device 20 will displace the piston 44 upward and, thus, cause the engagement members 28 to displace radially inward into engagement with the recess 42, thereby securely latching the assembly 30 into the housing 26.
The plates 94 urge the engagement members 28 to displace radially inward and outward (and longitudinally upward and downward) together as a unit. The plates 94 could also be provided with circumferentially extending interlocking grooves or other profiles, so that the engagement members 28 are constrained to displace together.
In some examples, the plates 94 could be integrally formed with the engagement members 28, or differently shaped structures could be used to interlock the engagement members. Thus, the scope of this disclosure is not limited to any particular configuration of the plates 94 and/or engagement members 28 and, indeed, use of the plates is not necessary at all.
Comparing the latched and unlatched configurations of
In this example, the engagement members 28 and plates 94 do not overlap each other. Instead, each engagement member 28 is independently displaced by its associated actuator 86.
It may now be fully appreciated that the above disclosure provides significant advances to the art of constructing and operating rotating control devices. In examples described above, the assembly 30 can be conveniently and reliably latched into and unlatched from the outer housing 26. In some examples, the assembly 30 can be latched into the housing 26, without a necessity of applying pressure to the latch 24.
The above disclosure provides to the art a method of releasably latching an assembly 30 relative to an outer housing 26 of a rotating control device 12. In one example, the method can comprise: inserting the assembly 30 into the outer housing 26, thereby outwardly displacing at least one engagement member 28 of a latch 24; and positioning the assembly 30 in the outer housing 26 at an operative position, thereby allowing the engagement member 28 to displace inward and engage a recess 42 on the assembly 30.
The inserting and the outwardly displacing steps may be performed without applying pressure to an actuator 86 of the latch 24.
The inserting step can include the assembly 30 contacting the engagement member 28 and pushing the engagement member 28 outward.
The method may include applying pressure to an actuator 86 of the latch 24 (such as, to port 46) after the positioning step, thereby maintaining the engagement member 28 engaged with the recess 42.
The positioning step can include a biasing device 20 of the latch 24 elongating and thereby causing the engagement member 28 to displace inward into engagement with the recess 42. The elongating step may include the biasing device 20 longitudinally displacing a piston 44 of the latch 24.
Multiple circumferentially distributed engagement members 28 may be provided, and each of the engagement members 28 may be interlocked with circumferentially adjacent ones of the engagement members 28 (for example, using separate or integrally formed plates 94).
The assembly 30 can include an annular seal 32 and/or a bearing 36. In other examples, the assembly could comprise a protective sleeve (not shown) for protecting seal bores, shoulders and other structures in the outer housing 26. Thus, it is not necessary for the assembly to include an annular seal and/or a bearing.
A rotating control device 12 is also provided to the art by the above disclosure. In one example, the rotating control device 12 can include an outer housing 26, at least one assembly 30 in a passage 16 extending through the outer housing 26, and a latch 24 in the outer housing 26, the latch 24 including at least one engagement member 28 which releasably secures the assembly 30 relative to the outer housing 26. The engagement member 28 is biased toward an engaged position by a biasing device 20 which exerts a longitudinally directed biasing force on a piston 44.
The engagement member 28 may displace both radially and longitudinally in response to longitudinal displacement of the piston 44.
The engagement member 28 may engage a recess 42 formed on the assembly 30. The engagement member 28 can be positioned between a first inclined face 84 of the recess 42 and a second inclined face 80 in the outer housing 26.
The first and second inclined faces 84, 80 may oppose each other. The first and second inclined faces 84, 80 can be substantially parallel to each other.
Another method of releasably latching an assembly 30 relative to an outer housing 26 of a rotating control device 12 is described above. In this example, the method can comprise: applying pressure to an actuator 86 of a latch 24 of the rotating control device 12; then positioning the assembly 30 in the outer housing 26 at an operative position; and then reducing the pressure, thereby allowing a biasing device 20 to displace at least one engagement member 28 of the latch 24 into engagement with a recess 42 formed on the assembly 30.
The applying pressure step can include compressing the biasing device 20. The pressure reducing step can include allowing the biasing device 20 to elongate.
The method may include, after the pressure reducing step, applying pressure to the actuator 86 (such as, to port 46), thereby maintaining the engagement member 28 engaged with the recess 42.
The pressure reducing step may include the biasing device 20 longitudinally displacing a piston 44 of the latch 24.
The piston 44 can be displaced to its unlatched position manually, such as, by threaded engagement between the piston and a threaded member 60.
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,” 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.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2013/072245 | 11/27/2013 | WO | 00 |