STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable.
BACKGROUND
This disclosure relates to the field of fluid connections, including without limitation pressure control devices used in connection with wells drilled into subsurface earthen formations. More specifically, the disclosure relates to well pressure control devices having remotely operable locking mechanisms whereby personnel may be moved away from such wells during connection and disconnection of the device to a wellhead.
U.S. Pat. No. 9,644,443 issued to Johansen et al. and U.S. Pat. No. 9,670,745 issued to Johansen et al. disclose various embodiments of a remotely operable well pressure control apparatus. Such well pressure control apparatus include a generally tubular pressure control equipment (PCE) adapter configured to mate with pressure control equipment at a first adapter end, and with a receptacle inside a generally tubular pressure control assembly at a second adapter end. The pressure control assembly is configured to mate with a wellhead. Cooperating abutment surfaces form a high pressure seal when the second adapter end is compressively received into the receptacle. A plurality of cam locks on the exterior of the pressure control assembly rotate responsive to extension and retraction of the cam lock pistons. Cam lock rotation causes perimeter curvatures on the cam locks to bear down on corresponding curvatures on the second adapter end, which in turn compresses the second adapter end into the receptacle to form the seal. A lock ring may restrain the cam locks from rotation while the seal is enabled.
The pressure control apparatus described in the foregoing two patents enable connecting the PCE adapter to the pressure control assembly and disconnecting the PCE adapter therefrom without the need to have personnel proximate the wellhead. Having such capability improves operating efficiency and reduces hazards to personnel.
Certain well intervention operations, such as hydraulic fracturing, coiled tubing operations, perforating and others may require pumping fluid into a well at pressures that can exceed 20,000 pounds per square inch (PSI), equivalent to about 138,000 kPa. Such pressures may make it difficult to scale the apparatus disclosed in the foregoing two patents to withstand such pressures. Accordingly, there is a need for a fluid connection that can, if needed, be remotely operated while at the same time being capable of withstanding such pressures.
SUMMARY
A fluid connection according to one aspect of the present disclosure comprises a fluid connector housing having a coupling at one end affixable to fluid transfer equipment. The fluid connector housing has a seal bore in an interior thereof. A pressure control adapter has a seal on an exterior thereof engageable with the seal bore. The pressure control adapter comprises a lock engagement surface. The pressure control adapter comprises a maximum outer diameter section. A plurality of locking elements is coupled to the fluid connector housing by a respective pivot. Each of the plurality of locking elements comprises an inner working surface and an outer working surface on one side of the respective pivot and a contact surface on the other side of the respective pivot. Each inner working surface has a taper opposed to a taper of the lock engagement surface. The contact surfaces and the maximum outer diameter section are arranged such that the inner working surfaces contact the lock engagement surface. A lock ring coupled to the fluid connector housing by at least one actuator longitudinally extensible with respect to the pressure control assembly housing, whereby when extended the lock ring is positioned to expose the outer working surfaces, and when retracted the lock ring surrounds the outer working surfaces of locking elements.
Some embodiments comprise three circumferentially positioned actuators coupled to the fluid connector housing and the lock ring.
In some embodiments, the at least one actuator comprises a hydraulic actuator.
In some embodiments, the inner working surfaces cover substantially the entire circumference of the lock engagement surface when the inner working surfaces engage the lock engagement surface.
Some embodiments further comprise a locking feature on each outer working surface and a corresponding feature on an inner working surface of the lock ring.
In some embodiments, the locking feature comprises a groove and the corresponding feature comprises a ridge.
In some embodiments, the fluid connector housing comprises a feature for connection with a pressure tight fluid connector.
In some embodiments, the pressure tight fluid connector comprises a wellhead.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A and FIG. 1B show components of a fluid connection such as a well pressure control apparatus including a fluid connection according to the present disclosure as it may be assembled to fluid transfer equipment such as a wellhead.
FIGS. 1C through 1F show various embodiments of a pressure control adapter.
FIG. 1 shows a cut-away view of an example embodiment of a fluid connection according to the present disclosure wherein a pressure control adapter is being inserted into a fluid connector housing affixable to a pressure tight fluid connector.
FIG. 2 shows a cut-away view as in FIG. 1, wherein the pressure control adapter has moved longitudinally into the fluid connector housing past the axial position of a plurality of locking elements to cause engagement of the locking elements with the exterior of the well pressure control adapter by radial motion of the locking elements.
FIG. 3 shows the cut away view of FIG. 2 wherein a lock ring is moved longitudinally to surround the locking elements.
FIG. 4 shows the cut away view of FIG. 3 wherein pressure is applied to the fluid connection to move the pressure control adapter to engage a lock engagement surface with the locking elements to as to urge them radially outwardly.
FIG. 5 shows an enlarged view of the lock engagement surface with the locking elements prior to applying pressure so as to better illustrate a retaining feature on the lock ring and on the locking elements.
FIG. 6 shows the view of FIG. 5 after pressure is applied so that the retaining features on the locking elements and on the lock ring are engaged.
FIGS. 7 and 8 show a cross-sectional view and a perspective view of one embodiment of locking elements comprising torsion springs.
FIGS. 9 through 12 show various views of a fluid connection according to the present disclosure.
DETAILED DESCRIPTION
FIG. 1A shows a partial illustration of an example embodiment of a fluid connection. The present example embodiment may be remotely operated if needed. The present example embodiment is described in terms of a well pressure control apparatus, however, the scope of the present disclosure is not limited to well pressure control apparatus. The fluid connection 10 may comprise a fluid connector housing 14, which in the present embodiment may be a well pressure control assembly housing having features thereon to enable pressure tight connection of the fluid connector housing 14 to fluid transfer equipment such as a wellhead W. The wellhead W may comprise a well pressure control device such as a blowout preventer stack BOP1 affixed thereto at one longitudinal end and at the other longitudinal end to the well pressure control assembly housing 14 through a suitable fitting F, for example mating flanges. In some embodiments, a hydraulic fluid pump such as a hand operated pump may provide hydraulic pressure to operate one or more actuators, as will be explained in more detail with reference to FIG. 3. FIG. 1B shows a pressure control adapter 12, which in the present example embodiment may be a well pressure control adapter, that may be inserted into the fluid connection, e.g., well pressure control apparatus of FIG. 1A. The pressure control adapter 12 may comprise, at a longitudinal end opposed to the longitudinal end to be inserted into the well pressure control assembly housing 14, a well pressure control device such as a blowout preventer BOP2. Other embodiments may have devices such as a coiled tubing unit (not shown) a fracture fluid pumping line or other devices used in well pressure control operations. Either or both blowout preventers BOP1, BOP2 may be of any type known in the art for controlling entry into and discharge from of fluid in a wellbore.
In other embodiments, different types of pressure control adapters may be used as will be explained in more detail with reference to FIGS. 1C through 1F. FIG. 1C shows a blank “stinger” as the pressure control adapter 12, wherein insertion thereof and locking in the fluid connector housing (14 in FIG. 1A) may provide a positive fluid closure preventing escape of fluid under pressure communicated to the opposite side of the fluid connector housing (14 in FIG. 1A). FIGS. 1D and 1E show various embodiments of a flanged coupling on one end of the pressure control adapter 12. Such flanges may be used to couple the pressure control apparatus (10 in FIG. 1A) to a pipeline, flow line or other fluid conduit. FIG. 1F shows a “goat head” pressure control adapter that may be used in certain types of well intervention operations such as hydraulic fracturing. The various structures of pressure control adapter shown and described herein are not intended to limit the scope of the present disclosure.
FIG. 1 shows a cut away view of an example embodiment of the pressure control adapter 12 as it is being inserted into the fluid connector housing 14. The fluid connector housing 14, in the present example embodiment being a well pressure control assembly housing, may comprise a coupling 14A at one end to enable affixing the fluid connector housing 14 to the fluid transfer equipment (e.g., the wellhead W as explained with reference to FIGS. 1A and 1B). The pressure control adapter 12 may comprise an enlarged outer diameter (OD) section 12B that acts as a positive stop to enable the pressure control adapter 12 to enter the fluid connector housing 14 only to a predetermined longitudinal position. A guide funnel 20 may be provided to assist directing the pressure control adapter 12 into the fluid connector housing 14. In some embodiments, the guide funnel 20 may be attached to a lock ring 18 (to be explained further below). The enlarged OD section 12B may also urge a plurality of locking elements 17 to move radially inward toward the well pressure control adapter 12 as the enlarged OD section 12B is moved longitudinally through an opening defined by contact surfaces 17C formed into each of the plurality of locking elements 17. Such radial movement may be effected by mounting the locking elements 17 pivotally within an actuator housing 16 that may be coupled to or formed integrally with the fluid connector housing 14. The locking elements 17 may each be so mounted on a corresponding pivot pin 16A engaged with the actuator housing 16. Thus as shown in FIG. 1, when the pressure control adapter 12 is initially lowered into the fluid connector housing 14, the locking elements 17 are radially expanded or in an “open” position with reference to their respective outer 17B and inner 17A working surfaces. When the locking elements 17 are so radially expanded, the pressure control adapter 12 may freely pass through an opening defined by the inner working surfaces 17A. The pressure control adapter 12 may comprise a first seal section 12C and a second seal section 12C1 that sealingly engage corresponding seal bores 15A, 15B inside the fluid connector housing 14. The pressure control adapter 12 may also comprise a locking element actuating section 12D. The locking elements 17 may be caused to radially contract or be moved radially inwardly at their respective working surfaces (17A and 17B) by the action of the locking element actuating section 12D of the pressure control adapter 12 as it moves longitudinally through the contact surfaces 17C and urges the contact surfaces 17C radially outwardly. The pressure control adapter 12 may comprise a tapered lock engagement surface 12A having a taper corresponding to and opposite in direction to a taper on the inner working surfaces 17A of the locking elements 17. Interaction between the inner working surfaces 17A and the lock engagement surface 12A will be further explained.
Referring to FIG. 2, as the pressure control adapter 12 continues to be moved into the fluid connector housing 14, the locking element actuating section 12D begins to contact the contact surfaces 17C on the plurality of locking elements 17 such that the working surfaces 17A and 17B will move radially inwardly as the pressure control adapter 12 continues longitudinal movement through the fluid connector housing 14. Such radial inward movement of the locking elements 17 at their working surfaces 17A and 17B restrains the well pressure control adapter 12 from opposite longitudinal movement (i.e., out of) within the fluid connector housing 14.
Referring to FIG. 3, once the pressure control adapter 12 is moved into the fluid connector housing 14 to a limit of longitudinal movement within the fluid connector housing 14, the lock ring 18 may be moved downwardly so as to cause an inner locking surface 18A of the lock ring 18 to surround the outer working surfaces 17B of the locking elements 17. One or more actuators 28, for example hydraulic actuators, may be used to move the lock ring 18 longitudinally from the extended position shown in FIGS. 1 and 2 to the retracted position shown in FIG. 3. The actuator(s) 28 may be coupled to the lock ring 18 by a respective ram or other link 26. Thus surrounded by the lock ring 18, the locking elements 17 are constrained to remain in their radially inward positions.
Referring to FIG. 4, when fluid pressure, e.g., from the wellhead (W in FIG. 1A) or other fluid transfer equipment is ultimately applied to the fluid connector housing 14 and thereby to the pressure control adapter 12, a longitudinal (upward in FIG. 4) force exerted on the pressure control adapter 12 is translated to radially outward force on the locking elements 17 by the interaction of the tapered lock engagement surface 12A with the inner working surfaces 17A of the locking elements 17. The inner working surfaces 17A may comprise an oppositely oriented taper thereon, as previously explained, to enable such interaction between the inner working surfaces 17A and the tapered lock engagement surface 12A. A taper angle for such surfaces 12A, 17A may be chosen so that the above described force translation takes place as well as providing relatively easy disengagement of the tapered lock engagement surface 12A from the inner working surfaces 17A. Radial expansion of the locking elements 17 is constrained when in the arrangement shown in FIG. 4 by contact between the outer working surfaces 17B and the inner locking surface 18A of the lock ring 18. The word “taper” in the present context includes within its scope any form of change in diameter with respect to longitudinal position, and specifically includes any shape of curved taper, i.e., other than flat taper.
It will be appreciated that the foregoing arrangement provides that most of the longitudinal force on the well pressure control adapter 12 resulting from pressure therein and within the fluid connector housing 14 is translated into radial outward force on the locking elements 17.
FIG. 5 shows an enlarged view of one of the locking elements 17, the lock engagement surface 12A on the pressure control adapter 12 and the inner locking surface 18A of the lock ring 18 to illustrate an additional locking feature 17A1 on each locking element 17 and a corresponding feature 18A1 on the lock ring 18. In the present example embodiment, the additional locking feature 17A1 may comprise a groove. The corresponding locking feature 18A1 may comprise a geometrically inverted ridge shaped to fit within the groove. In FIG. 5, the pressure control adapter 12 is disposed longitudinally in the fluid connector housing (14 in FIG. 3) as shown in FIG. 3 prior to pressurizing the pressure control apparatus. In such condition, the pressure control adapter 12 is inserted longitudinally in the fluid connector housing (14 in FIG. 3) to its insertion limit. Thus, the locking elements 17 may be rotated to their corresponding radial limit.
Referring to FIG. 6, when pressure is applied to the fluid connection (10 in FIG. 1) and as explained with reference to FIG. 4, the pressure control adapter 12 will move outwardly from the fluid connector housing 14, causing the external tapered surface 12A to engage the outer working surface 17B. Such engagement causes the locking elements 17 to expand radially so as to contact the inner locking surface 18A of the lock ring 18. Such contact urges the locking feature 17A1 into contact with the corresponding locking feature 18A1 thereby providing restraint on longitudinal movement of the lock ring 18. For example, such contact may prevent inadvertent movement of the lock ring 18 by operation of the one or more actuators (28 in FIGS. 1 through 4), thereby increasing safety of the pressure control apparatus when pressure is applied thereto.
FIGS. 7 and 8 show a cross-sectional view and a perspective view, respectively of another embodiment of the fluid coupling. In the embodiment shown in FIGS. 7 and 8, each locking element 17 may be urged toward its radially open position, that is, in the position shown in FIG. 1 wherein the pressure control adapter 12 may pass through the locking elements 17 unimpeded. Such unimpeded motion may continue until the locking element actuating section 12D contacts the contact surfaces 17C on the locking elements to rotate the locking elements 17 to their “closed” position. In the present embodiment, each locking element may be so urged by a corresponding biasing element, such as a torsion spring 16B. Each torsion spring 16B may be arranged to that one end contacts the corresponding locking element 17. A possible arrangement of the torsion springs 16B is shown in oblique view in FIG. 8. The example embodiment shown in FIGS. 7 and 8 is only one example of a biasing element according to the present disclosure.
FIGS. 9 through 12 show various views of a fluid connection according to the present disclosure. In FIG. 9, the assembled fluid connection is shown in vertical orientation such as may occur when the fluid connection is affixed to a wellhead as explained with reference to FIG. 1A. FIG. 10 shows a plan view of the fluid connection, wherein three, circumferentially spaced apart actuators 28 may be used to move the lock ring 18. FIG. 11 shows the fluid connection 10 in horizontal orientation, such as may be used when the fluid connection is used within a fluid conduit, for example and without limitation, a coupling between a hydraulic fracture fluid pumping unit and a fracture fluid manifold. In FIG. 9, a stinger 12 as explained with reference to FIG. 1C is disposed in the apparatus, although the configuration of FIG. 11 is not intended to limit the scope of the present disclosure. FIG. 12 shows an oblique view of the fluid connection 10 having a stinger 12 inserted therein. Thus, a fluid connection according to the present disclosure may be used for connecting various fluid carrying devices to various forms of fluid transfer equipment.
A fluid connection made according to the various aspects of the present disclosure may be operated easily and remotely as pressure control devices known in the art prior to the present disclosure, but with the capacity to withstand much higher pressure without imparting excessive axial strain on the pressure control adapter and pressure control adapter housing.
Although the various aspects of the present disclosure have been described above, in part, with reference to particular examples, those skilled in the art will readily appreciate that many modifications are possible in the examples. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.
Patent Application
20190301260
