ADJUSTMENT AND RESTRAINT SYSTEM FOR SUBSEA FLEX JOINT

Abstract

An adjustment and restraint system for a subsea flex joint may include a pusher saddle to be installed on a flex joint top plate and a hydraulic cylinder to be disposed in the pusher saddle. The hydraulic cylinder may be used to adjust a tilt angle of the adapter spool. A holder saddle may also be installed on the flex joint top plate. The hydraulic cylinders, the holder saddles, holder members, or a combination thereof may be used to restrain the adapter spool in the upright position.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/482,132 filed May 3, 2011.

BACKGROUND

In offshore drilling operations, a blowout preventer (BOP) is installed on a wellhead at the sea floor and a lower marine riser package (LMRP) is mounted to the BOP. In addition, a drilling riser extends from a flex joint at the upper end of LMRP to a drilling vessel or rig at the sea surface. The flex joint absorbs loads and motions caused by water currents and movement of the drilling vessel or rig, so that the connection between the LMRP and the riser is not disturbed. A drill string is then suspended from the rig through the drilling riser, LMRP, and the BOP into the well bore. A choke line and a kill line are also suspended from the rig and coupled to the BOP, usually as part of the drilling riser assembly.

During drilling operations, drilling fluid, or mud, is delivered through the drill string, and returned up an annulus between the drill string and casing that lines the well bore. In the event of a rapid influx of formation fluid into the annulus, commonly known as a “kick,” the BOP and/or LMRP may be actuated to seal the annulus and control the well. In particular, BOPs and LMRPs comprise closure members capable of sealing and closing the well in order to prevent the release of gas or liquids from the well. Thus, the BOP and LMRP are used as devices that close, isolate, and seal the wellbore. Heavier drilling mud may be delivered through the drill string, forcing fluid from the annulus through the choke line or kill line to protect the well equipment disposed above the BOP and LMRP from the high pressures associated with the formation fluid.

The flex joint may become tilted or angled relative to the sea floor or other wellhead equipment during operations. Accordingly, there remains a need in the art for systems and methods to move the tilted flex joint to a more upright position relative to the sea floor before additional devices can be attached to the top of an adapter of the flex joint. Further, it may also be desirable to secure the flex joint in the upright position.

SUMMARY

An adjustment and restraint system for a subsea flex joint may include a pusher saddle to be installed on a flex joint top plate and a hydraulic cylinder to be disposed in the pusher saddle. The hydraulic cylinder may be used to adjust a tilt angle of the adapter spool. A holder saddle may also be installed on the flex joint top plate. The hydraulic cylinders, the holder saddles, holder members, or a combination thereof may be used to restrain the adapter spool in the upright position.

Thus, embodiments described herein comprise a combination of features and advantages intended to address various shortcomings associated with certain prior devices, systems, and methods. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of exemplary embodiments of the invention, reference will now be made to the accompanying drawings in which:

FIG. 1 is a schematic view of an embodiment of an offshore drilling system;

FIG. 2 is an enlarged, partial cross-section view of the riser flex joint of the lower marine riser package of FIG. 1;

FIG. 3 is a schematic view of the offshore drilling system of FIG. 1 tilted relative to the sea floor;

FIG. 4 is an enlarged view of the tilted riser flex joint of the lower marine riser package of FIG. 3;

FIG. 5 is an upper perspective view of a pusher saddle of an exemplary flex joint adjustment mechanism;

FIG. 6 is a lower perspective view of the pusher saddle of FIG. 5;

FIG. 7 is a front view of the pusher saddle of FIGS. 5 and 6;

FIG. 8 is a longitudinal cross-section view of the pusher saddle of FIGS. 5-7;

FIG. 9 is a longitudinal cross-section view of the pusher saddle supporting a hydraulic cylinder assembly;

FIG. 10 is a perspective view of the pusher saddle of FIGS. 5-8 disposed atop a flex joint top plate;

FIG. 11 is a perspective view of the pusher saddle assembly of FIG. 9 disposed atop a flex joint top plate;

FIG. 12 is a perspective view of an alternative embodiment of a pusher saddle;

FIG. 13 is a perspective view of the pusher saddle of FIG. 12 including a hydraulic cylinder to form a pusher saddle assembly;

FIG. 14 is a perspective view of a plurality of pusher saddle assemblies including hydraulic cylinders disposed on the flex joint top plate about the adapter spool to form an exemplary flex joint adjustment mechanism;

FIG. 15 is a top view of the adjustment mechanism of FIG. 14;

FIGS. 16-18 are side schematic views of a hydraulic cylinder being installed in a pusher saddle, and pressured up and captured against a tilted adapter spool of a flex joint;

FIG. 19 is an upper perspective view of a holder saddle of an exemplary flex joint restraint mechanism;

FIG. 20 is a lower perspective view of the holder saddle of FIG. 19;

FIG. 21 is a side view of the holder saddle of FIGS. 19 and 20;

FIG. 22 is a front view of the holder saddle of FIGS. 19-21;

FIG. 23 is an upper perspective view of a holder saddle installed between a flex joint top plate and an adapter spool in accordance with the principles disclosed herein;

FIG. 24 is a perspective view of the holder saddle of FIG. 23 with a pin member installed therein;

FIGS. 25 and 26 are elevation views of a series of holder saddle and pin member assemblies installed between a flex joint top plate and an adapter spool;

FIG. 27 is schematic view of holder saddle assemblies installed between a flex joint top plate and an adapter spool;

FIG. 28 is an upper perspective view of an embodiment of an adapter spool restraint system including the holder saddle assemblies of FIG. 27;

FIG. 29 is a schematic view of a hydraulic distribution and control panel operable by ROV; and

FIG. 30 is a flowchart illustrating an exemplary embodiment of a method for adjusting and restraining a tilted flex joint adapter spool.

DETAILED DESCRIPTION

In the drawings and description that follow, like parts are typically marked throughout the specification and drawings with the same reference numerals, respectively. Certain terms are used throughout the description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results.

The terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” Unless otherwise specified, any use of any form of the terms “couple”, “attach”, “connect” or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis.

Referring initially to FIG. 1, an embodiment of an offshore system 100 for drilling and/or producing a wellbore 101 is shown. In this embodiment, system 100 includes an offshore platform 110 at the sea surface 102, a subsea blowout preventer (BOP) 120 mounted to a wellhead 130 at the sea floor 103, and a lower marine riser package (LMRP) 140. Platform 110 is equipped with a derrick 111 that supports a hoist (not shown). A drilling riser 115 extends from platform 110 to LMRP 140. In general, drilling riser 115 is a large-diameter pipe that connects LMRP 140 to the floating platform 110. During drilling operations, riser 115 takes mud returns to the platform 110. Casing 131 extends from wellhead 130 into subterranean wellbore 101.

BOP 120 has a central or longitudinal axis 125 and includes a body 123 with an upper end 123a releasably secured to LMRP 140, a lower end 123b releasably secured to wellhead 130, and a main bore 124 extending axially between upper and lower ends 123a, b. Main bore 124 is coaxially aligned with wellbore 101, thereby allowing fluid communication between wellbore 101 and main bore 124. BOP 120 includes a plurality of axially stacked sets of opposed rams 127, 128, 129 to prohibit flow through the annulus around string 116 and/or main bore 124 when rams 127, 128, 129 are closed. LMRP 140 has a body 141 with an upper end 141a connected to the lower end of riser 115, a lower end 141b releasably secured to upper end 123a with connector 150, and a throughbore 142 extending between upper and lower ends 141a, b. Throughbore 142 is coaxially aligned with main bore 124 of BOP 110, thereby allowing fluid communication between throughbore 142 and main bore 124. LMRP 140 also includes an annular blowout preventer 142a.

Referring now to FIGS. 1 and 2, in this embodiment, upper end 141a of LMRP 140 comprises a riser flex joint 143 that allows riser 115 to deflect angularly relative to BOP 120 and LMRP 140 in response to loads and motions caused by water currents and movement of the platform 110. In this embodiment, flex joint 143 includes a cylindrical base 144 secured to the LMRP 140 and a riser adapter 145 extending upward from base 144. The adapter 145 includes an intermediate spool portion 154 with an angled load shoulder 155 on the lower portion of the adapter 145 and a lower end of the spool portion 154. A fluid flow passage 146 extending through base 144 and adapter 145 defines the upper portion of throughbore 142. A flex element 152 disposed within base 144 extends between base 144 and adapter 145, and engages both base 144 and riser adapter 145. The flex element 152 allows adapter 145 to pivot and angularly deflect relative to base 144, LMRP 140, and BOP 120 to accommodate water currents, platform 110 movements, or other loads and motions that might otherwise disturb or damage the connection between the LMRP 140 and the riser 115. The upper end of adapter 145 comprises an annular flange 145a for coupling adapter 145 to a mating annular flange 118 at the lower end of riser 115 or to alternative devices. Although LMRP 140 has been shown and described as including a particular flex joint 143, in general, any suitable riser flex joint may be employed in LMRP 140.

Referring now to FIG. 3, an exemplary scenario is shown wherein the riser 115 has been disturbed, damaged, and/or removed and the BOP 120 and LMRP 140 have been bent or tilted from substantially vertical relative to the sea floor 103 by a tilt angle α. A bottom portion of the riser 115 may remain atop the flex joint 143. In some embodiments, the tilt of the flex joint 145 may be included in the tilt angle α of the axis 125, while in other embodiments the adapter 145 may include a separate tilt angle relative to the flex joint base 144, the BOP 120, and/or the LMRP 140.

Referring next to FIG. 4, an angled or tilted position of the flex joint 143 is shown. An LMRP top plate 160 supports flex joint body or base 144 which now includes an inclination angle 162 relative to longitudinal axis 125 about a flex joint center of rotation 164. At the upper end of base 144 is a flex joint top plate 156 secured by a series of studs and nuts 158. The adapter 145 and adapter spool 154 include an inclination angle 166 relative to base 144, provided by flexibility in flex element 152 of FIG. 2. Thus, the adapter 145 and any riser 115 extension thereabove include a total inclination angle 168 relative to axis 125 in the tilted position of the flex joint 143 that preferably is addressed before any subsea equipment may be attached to the top of the adapter 145.

For example, embodiments of capping stacks can be deployed on top of the flex joint 143. But first, the LMRP 140 is preferably readied to receive the capping stack or other device. In part, the inclination or tilt angle 168 of flex joint 143 must be addressed. Tilt angle 168 decreases the likelihood of proper make up between the top of the adapter 145 and the capping stack or other device. The likelihood of proper make up is increased if angle 168 is decreased, or if the adapter 145 is moved to a more upright position relative to the axis 125 or relative to vertical to the sea floor 103. Moving the tilted or angled adapter 145 toward a more upright position may be defined as decreasing the tilt angle 168, moving the adapter 145 toward the axis 125, or, in some cases, moving the adapter beyond the axis 125 and toward a substantially vertical or perpendicular position relative to the sea floor 103.

Embodiments of a flex joint angle adjustment mechanism will now be described. In some embodiments, as will be described in more detail below, an adjustment and restraint system also includes restraint or holder mechanisms in addition to the angle adjustment mechanism. Referring now to FIG. 5, an adjustment base member 200 is shown (also referred to as a cylinder support body or pusher saddle). The pusher saddle 200 includes a top surface 202, a bottom surface 206, a rear surface 212 and a forward or adapter spool facing surface 210. Between the forward surface 210 and the top surface 202 is an upper pocket or cavity 204 including a rear support surface 207 and a lower support surface 205. In some embodiments, the surface 205 is U-shaped; while in other embodiments the surface includes other curves, a square shape, or other shapes. The geometries of these pockets surfaces 205, 207, including their angles relative to the bottom surface 206, are designed into the pusher saddle 200 as will be described herein. Between the bottom surface 206 and the rear surface 212 are lower pockets or cavities 208. FIG. 6 shows another perspective view of the pusher saddle 200, with particular focus on the dual lower pockets 208 for receiving studs and nuts 158 of a flex joint body top plate 156, as will be further described herein. FIG. 7 is a front view of the pusher saddle 200.

FIG. 8 is a longitudinal cross-section view showing the details of the pusher saddle 200 as described above. More particularly, the surface 205 includes an angle 209 relative to the bottom surface 206, and the surface 207 includes an angle 211 relative to perpendicular from the bottom surface 206, providing an overall angle 209, 211 for the pocket 204 relative to the bottom surface 206.

Referring now to FIG. 9, the pusher saddle 200 receives a hydraulic cylinder assembly 270. As shown, the hydraulic cylinder assembly 270 includes a cylinder member 272 that rests in the angled pocket 204 against the support surfaces 205, 207. The angled pocket 204 then supports the cylinder assembly 270 at approximately the same angle relative to the bottom surface 206. The cylinder member 272 receives a piston member 274 for reciprocal movement therein based on hydraulic pressure. The piston member 274 includes a contact member 276 with an outer contact surface 278 on its distal end. In some embodiments, the hydraulic cylinder assembly 270 includes a handle 290 for ROV manipulation. In some embodiments, the pusher saddle 200 includes a support member 280 mounted on the forward surface 210 and having a cylinder support extension 282 for engaging the cylinder member 272 and maintaining the cylinder assembly 270 at the angle provided by the angled pocket 204. In some embodiments, the pusher saddle 200 includes an ROV handle 260 mounted to the rear surface 212. Together, the pusher saddle 200 and the hydraulic cylinder assembly 270 may be referred to as a pusher saddle assembly or adjustment mechanism assembly 250.

The hydraulic cylinder assembly 270 may be any one of several robustly rated cylinders, including, for example, Enerpac® RC-502 hydraulic cylinders and/or Enerpac® RC-504 hydraulic cylinders which have an approximately 50-ton cylinder capacity. Hydraulic cylinders with various other capacities and characteristics are also contemplated and known to one having ordinary skill.

The pusher saddles 200 are disposable on the flex joint top plate 156, manipulated by remotely operated vehicles (ROV's) using the handles 260. With reference to FIG. 10, the pusher saddles 200 are disposed on top of the studs and nuts 158 of the top plate 156. The lower pockets or cavities 208 receive the studs and nuts 158 as shown, such that the pusher saddles 200 can react against the studs and nuts 158 for support. The angled pocket 204 and the cylinder support member 280 and extension 282 face the flex joint adapter spool 154. In some embodiments, the lower pockets 208 are provided such that the pusher saddles 200 can react against the studs and nuts 158 while also advantageously placing the angled pockets 204 and support surfaces 205, 207 opposite the angled load shoulder 155 of the adapter spool 154. As is contemplated and shown elsewhere herein, other support bodies may be located on and react against other portions of the flex joint top plate 156 while also taking into account the relationship the adjustment or holder member preferably has with respect to the adapter spool 154 and angled shoulder 155.

Referring now to FIG. 11, a hydraulic cylinder 270 can be lowered into an angled pocket 204 by ROV using a handle 290. The cylinder contact member 276 and contact surface 278 face the angled load shoulder 155 of the adapter spool 154. A hydraulic fluid supply line 273 is coupled to the hydraulic cylinder assembly 270. As previously mentioned, the pusher saddle 200 and the hydraulic cylinder assembly 270 together form the adjustment mechanism assembly 250. As illustrated in FIG. 11, the angled pocket 204 positions the cylinder assembly 270 such that the contact surface 278 is directed toward the angled shoulder 155. Further, a substantially direct load path is provided from the cylinder assembly 270 through the rear pocket surface 207 and the saddle body and ultimately to the studs and nuts 158.

Referring next to FIG. 12, an alternative embodiment of the pusher saddle is shown. A pusher saddle 300 includes many of the same features as the pusher saddle 200, including a top surface 302, a rear surface 312, an upper angled pocket 304 that faces the adapter spool 154, and lower pockets 308 for receiving and reacting against the studs and nuts 158. Unlike the pusher saddle 200, the pusher saddle 300 includes an extended front surface 310 including an upper curved portion 315. The curved portion 315 may shift some of the weight of the pusher saddle 300 toward the front surface of the pusher saddle 300, and also extend the angled pocket 304 to further restrain lateral movement of a hydraulic cylinder assembly 370. As shown in FIG. 13, the pusher saddle 300 receives the hydraulic cylinder 370 at an angle relative to the bottom surface of the pusher saddle 300 (and, thus, also relative to the flex joint top plate 156 upper surface) in the angled pocket 304, forming an alternative adjustment mechanism assembly 350 that also positions an outer contact surface 378 toward the angled load shoulder 155. A hydraulic fluid supply line 373 powers the hydraulic cylinder 370 such that a contact member 376 with the outer contact surface 378 can be extended toward engagement with the load shoulder 155 of the adapter spool 154.

Referring to FIG. 14, a plurality of adjustment mechanism assemblies 250, 350 are disposed on the studs and nuts 158 between the top plate 156 and the adapter spool 154. As will be described in more detail below, the adjustment mechanism assemblies 250, 350 can be actuated during an adjustment process to push the adapter spool 154 from various tilt angles as defined herein, such as angle 168, toward an upright position. As illustrated, the contact surfaces 278, 378 of the hydraulic cylinder assemblies 270, 370 are directed or aimed at the angled load shoulder 155 of the adapter spool 154. FIG. 15 is a top view of the installed adjustment mechanism assemblies 250, 350, awaiting actuation to begin the flex joint tilt adjustment procedure. The adjustment mechanism assemblies 250, 350 may be disposed in other various circumferential positions about the adapter spool 154 to provide the appropriate lateral adjustment forces to the adapter spool 154.

In operation, a hydraulic distribution and control panel 600 is located and secured onto subsea equipment, for example the LMRP, via ROV, as is typical and known by an operator of a subsea wellhead. Referring briefly to FIG. 29, a schematic of the hydraulic distribution and control panel 600 is shown. The panel 600 includes a hydraulic inlet 602, a series of hydraulic hot stab connections 604 that are coupled to corresponding gauges 606 and valves 608, and ROV handles 610. The inlet 602, connections 604, gauges 606 and valves 608 are all fluidly coupled through a network of flowlines 612.

An inclinometer with a magnetic base is mounted onto the tilted adapter spool 154, also not shown. The inclinometer's battery pack and digital display are mounted to the hydraulic distribution panel 600. Further instruments and tools may also be coupled to the system or otherwise used to measure and monitor tilt angles, pressures, forces, and other characteristics of the system and process, as is understood by one having skill in the art.

Periodic reference will now be made to the process flowchart in FIG. 30 as the operational process 700 is described. Securing the hydraulic distribution panel to the LMRP or other subsea equipment is seen at box 704. Next, a plurality of pusher saddles 200, 300 are positioned on the top plate 156 about the adapter spool 154 as illustrated in FIGS. 10, 14 and 15, using ROV's that grab the handles 260 (box 706 of FIG. 26). Then, with reference to FIGS. 11 and 16, the hydraulic cylinders 270 are grabbed by the ROV's via handles 290, and lowered into the angled pusher saddle pockets 204 until the cylinders 270 rest on the lower support surface 205 and the rear support surface 207 (FIG. 17) (box 708 of FIG. 26). Installation of the hydraulic cylinders is a sequential process described in more detail below. The adjustment mechanism assembly 250 is formed thereby, with help from the angled cylinder support member 280 which is optionally part of the adjustment mechanism assembly 250. The hydraulic cylinders 270 can then be plugged into the hydraulic distribution panel 600 via the supply lines 273, 373, in preparation for engagement with the adapter spool 154 having tilt angle 168.

To operably couple the hydraulic cylinder assemblies 270, 370 into the hydraulic distribution panel 600, a first ROV plugs a hot stab jumper into one of the connections 604 to provide a hydraulic flow path via the supply lines 273, 373. The specific ROV operations are not shown, as operation of ROV's is understood by those having skill in the art, and reference to assembly 250 only is made for ease and clarity of description. A second ROV positions the first connected hydraulic cylinder 270 in a pusher saddle 200, to complete installation of the first cylinder 270 as shown at box 708 of the process 700. A third ROV may then view or detect the hydraulic cylinder 270 to verify alignment such that the contact surface 278 is directed toward the angled shoulder 155.

The first ROV then actuates a valve 608 corresponding to the first connected hydraulic cylinder 270 to apply hydraulic pressure to the first cylinder 270 until it engages the angled load shoulder 155 of the adapter spool 154, as shown in FIG. 18, thus capturing the cylinder 270 between the angled geometry of the load shoulder 155 and the angled geometry of the rear surface 207 in the angled pocket 204 (box 710 of FIG. 26). The angled load shoulder 155 may be at an angle of 30 degrees from the longitudinal axis of the adapter spool 154. As also shown in FIG. 18, the cylinder 270 is free to adjust its position relative to the pocket surfaces 205, 207 in response to engagement with the angled shoulder 155 to maintain the interface 279 between the contact member 276 and the angled shoulder 155 wherein the contact surface 278 is flush with the angled shoulder 155 or substantially engaged with the angled shoulder 155. The geometry of the angled pocket 204 ensures that the cylinder 270 remains captured between the saddle 200 on the flex joint top plate 156 and the angled load shoulder 155. The geometry of the angled pocket 204 also provides a substantially direct load path through the cylinder 270, the support surface 207, the body of the saddle 200, and ultimately to the studs and nuts 158 disposed in the saddle pockets 208 or to the inner conical surface of the flex joint as explained above.

The first ROV then blocks pressure into the first engaged cylinder 270 to keep it in position. The second ROV can install a second cylinder 270, and it can be actuated and engaged with the shoulder 155 in a similar manner. The process is repeated until all of the predetermined number of hydraulic cylinders are in an engaged position with the angled load shoulder 155. Thus, the process of installing the hydraulic cylinder assemblies 270 in the pre-positioned pusher saddles 200 is sequential. In some embodiments, the determination of the number of cylinders to use, as represented at 712 of FIG. 26, is made at the surface before the operation begins. In other embodiments, the decision to add each sequential cylinder 270 can be made during the operation based on factors like the detected tilt angle 168 of the adapter spool 154, the weight of the adapter spool 154, the applied pressure to the installed hydraulic cylinders 270, and the like.

Next, the first ROV applies further hydraulic pressure to cause the captured hydraulic cylinders 270 to react between the angled load shoulder 155 and the angled pusher saddle pockets 204, which causes the pusher saddles 200 to react against the flex joint top plate's studs and nuts 158. Extension of the hydraulic cylinder pistons 274 moves the adapter spool 154 toward an upright position, represented as box 714 in FIG. 26. In some embodiments, depending on clearance and movement of the adapter spool 154, certain adjustment mechanism assemblies 250, 350 will have to be re-located and re-engaged to move the adapter spool 154 into a vertical orientation. In further embodiments, certain adjustment mechanism assemblies 250, 350 are moved to keep the adapter spool upright until holder or restraint mechanisms are available for installation.

The amount of hydraulic pressure applied during tilt adjustment can be monitored, and also varied depending on factors such as the size of the adapter spool 154, the static coefficient of friction of the adapter spool 154, the inclination angle 168, among other factors. Further, the total number of adjustment mechanism assemblies 250, 350 used for tilt adjustment can be varied based on similar factors, and also on the response of the adapter spool 154 to adjustment. The lengths of the pusher saddles 200, 300 are predetermined based on the angle 168 or other inclination angle of the adapter spool 154. As previously described, the opposing geometries of the angled pockets 204, 304 and the angled load shoulder 155 of the adapter spool 154 shoulder capture the hydraulic cylinders 270, 370 as they are being pressured up against the angled load shoulder 155. The cylinders 270, 370 will remain captured due to these geometries, even during a range of motion of the flex joint adapter spool 154 during the tilt adjustment operation.

In some embodiments, a determination is made, represented by box 718 in FIG. 26, that it is desirable to land the capping stack and the hydraulic cylinders 270, 270 installed as described above are used to restrain the adapter spool 154 (box 716) while landing the capping stack at box 720. Accordingly, the pressure in the cylinders 270, 370 is monitored to prevent damage to the system. In still other embodiments, a determination is made that the capping stack should not be landed while the hydraulic cylinders 270, 370 are engaged, at box 718, and the adjustment mechanism assemblies 250, 350 are replaced with a passive stopper system, also referred to as a restraint or holder member mechanism.

Referring now to FIG. 19, a restraint body or holder saddle 400 is shown. The holder saddle 400 includes a top surface 402, a bottom surface 406, a rear surface 412 and a forward or adapter spool facing surface 410. Between the forward surface 410 and the top surface 402 is an upper angled pocket or cavity 404 including a rear support surface 407 and a lower support surface 405 that may be U-shaped, curved, squared, or other shapes. Extending downward from the angled pocket 404 and including the forward surface 410 is a load or extension member 420 also including a distal end 422 with bottom surface 424. Distal end 422 is an extension that can react against the inside face of the flex joint so as to avoid overloading the nuts/studs. A radius surface 426 is disposed between the back of the extension member 420 and the bottom surface 406. Between the bottom surface 406 and the rear surface 412 are lower pockets or cavities 408.

Mounted onto or extending from the forward surface 410 is a nose portion 440. The nose portion 440 includes a top surface 442, a contact or engagement surface 444, and side surfaces 446. In some embodiments, the nose portion 440 is mounted to the forward surface 410, so the contact surface 444 includes bolt holes 445. In some embodiments, the contact surface 444 is curved. As shown in FIG. 20, the nose portion 440 includes a curved contact surface 444 and a bottom surface 448. Also shown are the dual lower pockets 408 for receiving studs and nuts of a flex joint body top plate, as will be further described herein.

Referring now to FIG. 21, a side view of the holder saddle 400 illustrates the angled nature of the surfaces 405, 407 of the angled pocket 404 with respect to the bottom surface 406 for capturing a holder member 500, 510, described more fully below. The surface 405 includes an angle 409 relative to the bottom surface 406, and the surface 407 includes an angle 411 relative to perpendicular from the bottom surface 406. The extension member 420 includes a rear surface 428 and the radius surface 426 for contacting and engaging a lip and inner surface 159 of the flex joint base 144 to provide a load path for the restraint mechanism. In some embodiments, the rear surface 428 includes a friction-inducing surface, such as teeth, or other surface for gripping the inner surface 159 of the flex joint base 144.

The nose portion 440 may be coupled to the forward surface 410 of the extension 420 by threading a bolt 447 through the recessed bolt hole 445 and into the extension member 420. Other ways of coupling the nose portion 440 to the extension 420 may also be employed, and the nose portion 440 may be integral with the extension 420. With the mountable embodiments of the nose portion 440, the nose portion 440 is replaceable. FIG. 22 illustrates a front view of the holder saddle 400 and the nose portion 440 having the contact surface 444 and the bolt holes 445. In some embodiments, the contact surface 444 includes a lubrication, for example, a dry moly aerosol or film lubricant or coating.

Referring now to FIG. 23, the holder saddle 400 can be placed atop the flex joint top plate 156 and over the studs and nuts 158 as shown. The extension member 420 and the nose portion 440 combine to place the contact surface 444 in close proximity to the adapter spool 154 for engagement. With engagement between the contact surface 444 and the adapter spool 154, as in the processes to be described more fully below, a load path 449 is established through the contact surface, the nose portion 440, the extension member 420, and to the flex joint top plate 156. A gap or space 425 between the lower pocket 408 and the studs and nuts 158 ensures that the previous load path through holder saddle body 400 and to the studs and nuts 158 is transferred to the load path 449. The arrangement shown in FIG. 23 is one embodiment of restraining or securing the adapter spool 154, without the use of a hydraulic cylinder or other holder member in the pocket 404.

Referring now to FIG. 24, another embodiment includes an arrangement for restraining or securing the adapter spool 154 wherein a holder pin 520 is installed in the pocket 404 via a ROV handle 560. When engaged with the angled load shoulder 155 of the adapter spool 154, the holder pin 520 provides an additional or supplementary load path 451 that ultimately leads into the load path 449 but from a different portion of the adapter spool 154. Again, the gap 425 ensures that the load path has been transferred from the studs and nuts 158. In some embodiments, the load paths 449, 451 work in conjunction to support the adapter spool 154, while in other embodiments one or the other load path alone supports the adapter spool 154.

Referring next to FIG. 25, a series of holder saddles 400 with nose portions 440 can be installed about the adapter spool 154. The curved contact surfaces 444 and the angled side surfaces 446 (FIGS. 19 and 20) of the nose portions 440 allow the nose portions 440 to fit neatly together in the space between the adapter spool 154 and the flex joint to plate (shown in FIG. 26). In some embodiments, the holder saddles 400 with nose portions 440 are disposed about the adapter spool 154 to restrain or secure the adapter spool 154 without the use of hydraulic cylinders, holder members, or pin members (the arrangement of FIG. 23). In other embodiments, the holder saddles 400 with nose portions 440 are disposed about the adapter spool 154 with the pin members 520. As is shown in FIG. 25, the pin member 520 may be placed in the holder saddle 400 with a gap between the pin member 520 and the angled shoulder 155, or the pin member 520 and the angled shoulder 155 may be engaged to fully install the pin member 520. Referring to FIG. 26, a series of holder saddles 400 are installed about a substantial portion of the adapter spool 154. The holder saddles are installed over the studs and nuts 158 on the flex joint top plate 156 via ROV handles 460 (though the gaps 425 of FIGS. 23 and 24 ensure that there is no lateral load transfer to the studs and nuts 158). The nose portions 440 are in close proximity to or engage the adapter spool 154 to establish the load path 449. The pin members 520 are positioned in the holder saddles 400 using the ROV handles 560. In some embodiments, the pin members 520 do not engage the angled shoulder 155 and instead are available for future or backup retention of the adapter spool 154. In other embodiments, a series of shims 521 may be used to adjust the length of the pin member 520 and engaged the angled load shoulder 155 for securing or restraining the adapter spool 154 through the load path 451.

Referring now to FIG. 27, the holder saddles 400 are configured to be placed atop the studs and nuts 158 of the flex joint top plate 156 as described before, but may also include other holder member 500, 510 embodiments or the hydraulic cylinders 270, 370 (FIG. 28). The radius surface 426 is disposed adjacent the inner lip of the top plate 156 and the extension member rear surface 428 contacts the inner surface 159 of the top plate 156. The nose portion 400 is disposed between the extension member 420 and the adapter spool 154. Thus, any force applied to the holder saddle 400 will react against the flex joint top plate 156 rather than the studs and nuts 158. The load path has been transferred from the studs and nuts 158 during hydraulic cylinder tilt adjustment to the flex joint top plate 156 via the extension member 420 and the nose portion 440 of the holder saddle 400 during adapter spool restraint. The holder or stopper member 500 may now be located in the angled pocket 404 and disposed between angled shoulder 155 and angled pocket 404. The opposing, angled geometries between the angled pocket 404 and the shoulder 155 capture the holder member 500. The installed holder member 500 completes a holder saddle assembly 450. In some embodiments, a holder member 510 is a different length than holder member 500 to accommodate different spaces between the holder saddles 400 and the adapter spool 154. Holder members 500, 510 may also include various other lengths. Holder member may also be replaced by pin members 520, hydraulic cylinders 270, 370, or be left out altogether because the nose portions 440 retrain the adapter spool 154.

The holder members 500, 510, 520 and the holder saddle assemblies 450 may have a higher load rating than the hydraulic cylinder assemblies 250, 350 because the ultimate load path does not include a hydraulic cylinder, but rather the solid holder members 500, 510 which do not depend on maintenance of the hydraulic pressure by pumps or another hydraulic power source. Further, the load path for the holder saddle assemblies 450 ultimately leads to the flex joint base 144 through the holder extension 420 and nose portion 440 instead of to the top plate studs and nuts 158 as with the adjustment mechanism assemblies 250, 350. In some embodiments, the holder members 500, 510 are solid cylinders or rods that replace the hydraulic cylinders and will take the load of the adapter spool and geometrically restrain the holder saddle. In some embodiments, the holder members 500, 510 are made from steel or other hard metal, or a composite material with high compressive strength and resistance to subsea conditions.

In operation, the holder saddles 400 or the holder saddle assemblies 450 may replace the adjustment mechanism assemblies 250, 350 that react against the studs and nuts 158 of the top plate 156 with the holder saddle assemblies 450 that react instead against the inside of the top plate 156. In some embodiments, the holder saddles 400 or the holder saddle assemblies 450 prevent the adapter spool 154 from reaching 2-degrees with respect to vertical relative to the sea floor 103. In some embodiments, the holder saddle assemblies 450 support solid holder members 500, 510, 520 of different lengths that will react between the same angled shoulder 155 on the adapter spool 154 and the angled pockets 404 of several holder saddles 400, which in turn react against the inner lip and surface 159 of the top plate 156. As previously described, the substantially upright position of the adapter spool 154 may be a position closer to the axis 125 of the BOP/LMRP, close to vertical relative to the seal floor 103, or another angle, but which decreases the tilt or inclination angle, such as angle 168, of the adapter spool 154.

First, and again with reference to process flowchart 700 of FIG. 30, a plurality of holder saddles 400 are installed (box 722 of FIG. 30) by ROV's using handles 460 as illustrated in FIG. 28. The holder saddles 400 are disposed in the empty locations between the pusher saddles 200, 300 and assemblies 250, 350, or in location vacated by the assemblies 250, 350. The nose portions 440 of the holder saddles 400 may then be used to restrain and secure the adapter spool 154 at box 703. In some embodiments, the adapter spool in restrained in this manner.

In other embodiments, next the adapter spool 154 orientation is verified to within the allowed tolerance to install the appropriate holder member 500, 510, 520 in a holder saddle 400. Then, the ROV is used to install the holder members 500, 510, 520 about the adapter spool 154 as shown in FIGS. 26 and 28 (box 724 of FIG. 30). In an alternative embodiment, the hydraulic cylinders 270, 370 are instead installed in the holder saddles 400 for adapter spool restraint, as is shown in the box 724. The ROV's and hydraulic distribution panel 600 are used to systematically vent hydraulic pressure and sequentially remove the pusher saddle hydraulic cylinders 270, 370 and their corresponding pusher saddles 200, 300, at box 726. In some embodiments, this is alternated with installing the holder saddles 400 and holder members 500, 510, 520 until an arrangement like that of FIG. 28 is established. Consequently, the holder saddle assemblies 450 may now maintain the adapter spool in the upright position. As is shown in FIG. 30, the hydraulic cylinders as installed in the pusher saddles may restrain the adapter spool, the holder saddles alone may restrain the adapter spool, the holder saddles with holder members installed may restrain the adapter spool, the holder members with hydraulic cylinders installed may restrain the adapter spool, or combination thereof may restrain the adapter spool.

While specific embodiments have been shown and described, modifications can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments as described are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the invention. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.

Claims

1. An adjustment and restraint system for a subsea flex joint, comprising:

a pusher saddle connected to a flex joint top plate, the pusher saddle including a pocket; and

a hydraulic cylinder configured to seat in the pocket of the pusher saddle, the pusher saddle configured to orient a contact surface of the cylinder toward a flex joint adapter spool.

2. The system of claim 1, wherein the flex joint adapter spool is in a tilted position prior to contact by the hydraulic cylinder contact surface.

3. The system of claim 1, wherein the pusher saddle comprises a lower cavity to receive a stud and a nut of the flex joint top plate.

4. The system of claim 1, wherein the pocket is angled relative to a top surface of the flex joint top plate.

5. The system of claim 4, wherein the pocket includes an angled lower support surface and an angled rear support surface that direct the hydraulic cylinder contact surface toward an angled shoulder of the flex joint adapter spool.

6. The system of claim 5, wherein the hydraulic cylinder is extendable to engage the contact surface with the angled shoulder, and the hydraulic cylinder is captured between the angled rear support surface and the angled shoulder.

7. The system of claim 4, wherein the hydraulic cylinder is operable to engage the contact surface with an angled shoulder of the adapter spool and capture the hydraulic cylinder between the opposed angled pocket and shoulder.

8. The system of claim 7, wherein the hydraulic cylinder is further operable to move the adapter spool from a tilted position to an upright position.

9. The system of claim 1, further comprising a plurality of pusher saddle and hydraulic cylinder combinations between the flex joint top plate and the flex joint adapter spool.

10. The system of claim 9, wherein the hydraulic cylinders are independently operable to react each contact surface against the flex joint adapter spool.

11. The system of claim 10, further comprising a hydraulic distribution panel including separate hydraulic connections for each hydraulic cylinder.

12. The system of claim 1, further comprising a holder saddle disposed on the flex joint top plate and a holder member configured to engage with the adapter spool, and the pusher saddle and hydraulic cylinder combination removable to be replaced by the holder saddle and holder member combination.

13. An adjustment and restraint system for a subsea flex joint, comprising:

a plurality of pusher saddles with lower pockets configured to receive studs and nuts of a flex joint top plate; and

a hydraulic cylinder configured to seat in an angled pocket of each of the pusher saddles, each hydraulic cylinder including a contact surface configured to engage with an angled shoulder of a tilted flex joint adapter spool;

wherein the hydraulic cylinders are independently operable to react the contact surfaces against the angled shoulder of the tilted flex joint adapter spool and move the tilted flex joint adapter spool to an upright position.

14. The system of claim 13, wherein the angled pockets oppose the angled shoulder to capture the hydraulic cylinders while engaged therebetween.

15. The system of claim 13, wherein a hydraulic distribution panel couples to each of the hydraulic cylinders to independently operate each hydraulic cylinder.

16. The system of claim 13, further comprising a plurality of holder saddles disposed over the studs and nuts of the flex joint top plate between the pusher saddles, and a holder member supported in each of the holder saddles to engage the angled shoulder.

17. The system of claim 16, wherein the holder saddles include lower extension members and nose portions, and the hydraulic cylinders and the pusher saddles are removable, and, upon removal of the hydraulic cylinders and the pusher saddles, a load path is transferred from the studs and nuts to the lower extension member, the nose portion, and the flex joint base.

18. A method of adjusting and restraining a subsea flex joint, comprising:

installing a plurality of pusher saddles on the studs and nuts of a flex joint top plate;

placing a hydraulic cylinder in an angled pocket of each of the pusher saddles; and

actuating the hydraulic cylinders to react a contact surface of each of the cylinders against an angled shoulder of a tilted flex joint adapter spool.

19. The method of claim 18, further comprising capturing the hydraulic cylinders between the opposed angled pockets and angled shoulder.

20. The method of claim 19, further comprising further pressuring the engaged hydraulic cylinders to move the tilted flex joint adapter spool to an upright position.

21. The method of claim 20, further comprising reacting the pusher saddles against the studs and nuts.

22. The method of claim 20, further comprising installing a plurality of holder saddles between the pusher saddles.

23. The method of claim 22, further comprising installing a holder member in each of the holder saddles.

24. The method of claim 23, further comprising venting hydraulic pressure from the hydraulic cylinders and removing the cylinders and pusher saddles.

25. The method of claim 24, further comprising transferring the load path from the studs and nuts to the flex joint base.

26. The method of claim 24, further comprising:

restraining the adapter spool with the holder members; and

landing the capping stack on the flex joint adapter extension.

27. The method of claim 22, further comprising restraining the adapter spool with the holder saddles, a holder member in the holder saddle, a hydraulic cylinder in the holder saddle, or a combination thereof.