Dual-activity riser joint and methods

Abstract

A system for subsea drilling includes a Y-connector including a hollow body. The Y- connector has a lower trunk having a lower passage in fluid communication with a main outlet; a first upper branch with a first inlet in fluid communication with a first outlet, the first upper branch being configured to operatively couple to a first marine riser, and the first outlet being in fluid communication with the lower passage of the lower trunk. The Y-connector also has a second upper branch with a second inlet in fluid communication with a second outlet, the second upper branch being configured to operatively couple to a second marine riser, and the second outlet being in fluid communication with the lower passage of the lower trunk. An articulating-rotating joint is configured to sealingly couple the lower trunk of the Y-connector to a blowout preventer. Methods for subsea drilling include installation and operation of such a system.

Description

Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFSTITLE OF THE APPLICATIONDUAL-ACTTVITY RISER JOINT AND METHODSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not applicable.BACKGROUND OF THE DISCLOSURE

[0002] The present disclosure relates generally to the field of subsea drilling for hydrocarbons. More particularly, the present disclosure relates to subsea drilling devices, systems, and methods, by which drilling, wireline, or completions operations may be conducted using two distinct marine risers.

[0003] In subsea drilling for hydrocarbons, a well may be drilled in the sea floor using a sequence of drilling processes and may be the subject of wireline or completions operations. The drilling, wireline, or completions operations are commonly conducted from a drilling platform — for example, a drillship or other floating support body carrying at least one pipe-handling derrick. In subsea drilling, a wellhead assembly and a blowout preventer (also known as a “BOP” or “BOP stack”) are located on or near the sea floor. The BOP stack is latched to the wellhead assembly. A marine riser, which is a pipe serving as a conduit between the BOP stack and the drilling platform, is latched to the BOP stack. Thereafter, drilling, wireline, or completions operations may be performed through the marine riser, the BOP stack, and the wellhead assembly. The marine riser is serviced by a derrick on the drilling platform and may be accessed through a “moon pool” or opening providing a passage from a deck of the drilling platform and providing access to the marine riser.

[0004] In certain systems, sometimes known as “dual-activity systems,” the drillship is configured and equipped for servicing two marine risers. U.S. Pat. No. 6,443,240 (“Scott”), the{00359234;vl} 1Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS contents of which are incorporated herein, conducting devices and methods for conducing drilling, wireline, or completions operations through a first marine riser while assembling drill pipe, tools, or other equipment in the second marine riser. The use of two marine risers saves time as compared to use of a single marine riser. When a drilling, wireline, or completions operation (or a combination thereof) uses a single marine riser, the operation must be halted when drilling equipment used in the single marine riser requires modification or maintenance. In contrast, in a dual -activity system employing two marine risers, the equipment in the first marine riser can be modified or maintained in the first marine riser, while equipment in the second marine riser can be operated to continue the drilling, wireline, or completions operations.

[0005] The present disclosure relates to improved devices and methods for use in dual-activity systems.SUMMARY OF THE DISCLOSURE

[0006] Briefly stated, in a first embodiment, a system for subsea drilling includes: a Y-connector including a hollow body, the Y-connector having: a lower trunk having a lower passage in fluid communication with a main outlet; a first upper branch with a first inlet in fluid communication with a first outlet, the first upper branch being configured to operatively couple to a first marine riser, and the first outlet being in fluid communication with the lower passage of the lower trunk; and a second upper branch with a second inlet in fluid communication with a second outlet, the second upper branch being configured to operatively couple to a second marine riser, and the second outlet being in fluid communication with the lower passage of the lower trunk; and an articulating-rotating j oint configured to sealingly couple the lower trunk of the Y-connector to a blowout preventer.The first embodiment may include any combination of optional features discussed in this paragraph. The system may further include one or more of the following: a first isolation valve disposed between the first inlet and the first outlet; a second isolation valve disposed between the second inlet and the second outlet; and a third isolation valve disposed between the lower trunk and the main outlet. The system may include the Y-connector being configured to sealingly couple a selected one of the first upper branch or the second upper branch in fluid communication with the lower trunk. The articulating-rotating joint may comprise a ball joint. The articulating-rotating joint may include: a housing; and a ball body seated within the housing for articulation and rotation with respect to the housing, wherein the ball body is sealingly engaged with the housing so that theDocket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS articulating-rotating joint provides a sealed connection joining the main outlet of the Y-connector to the blowout preventer. The system may further include a seal disposed between the housing and the ball body. The articulating-rotating joint may comprise one or more of a spherical roller bearing or packing-sealing elements. The articulating-rotating joint may comprise at least one rotary seal. The system may further include a closure body movable between: a first position opening a path between the first inlet and main outlet; and a second position opening a path between the second inlet and the main outlet. The first position of the closure body may close the path between the second inlet and main outlet; and the second position of the closure body closes a path between the first inlet and the main outlet. The system may further include a lubricator operatively coupled to lubricate the articulating-rotating joint or other components of the system. The system may further include a controller operatively coupled to at least one of the blowout preventer, the lubricator, the first isolation valve, the second isolation valve, or the third isolation valve.

[0007] In a second embodiment, the system may include: a first marine riser configured to be operatively coupled to a drilling platform, the first marine riser comprising a first upper-marine-riser segment and a first lower-marine-riser segment; a second marine riser configured to be operatively coupled to the drilling platform, the second marine riser comprising a second upper-marine-riser segment and a second lower-marine-riser segment; a first rotating-ball-joint-valve configured to operatively couple the first upper-marine-riser segment to the first lower-marine-riser segment; a second rotating -ball-joint-valve configured to operatively couple the second upper-marine-riser segment to the second lower-marine-riser segment; and a third rotating-ball-joint-valve operatively first marine riser and the second marine riser to a blowout preventer. The second embodiment may further comprise a swivel connector disposed between the third rotating-ball-joint-valve and the blowout preventer. The second embodiment may further comprise a tension ring with at least one tension member attached thereto, operatively attached to the first marine riser, and configured to place the first marine riser selectively in a state of increased or decreased tension; and a second tension ring with at least one tension member attached thereto, operatively attached to the second marine riser, and configured to place the second marine riser selectively in a state of increased or decreased tension.

[0008] In a third embodiment, a method of drilling for hydrocarbons includes installing a wellhead assembly on or near a sea floor; connecting a blowout preventer to the wellhead assembly; connecting the blowout preventer to an articulating-rotating joint; connecting a Y-connector to the articulating- rotating joint, the Y-connector having: a lower trunk having a lower passage in fluid communicationDocket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS with a main outlet; a first upper branch with a first inlet in fluid communication with a first outlet, the first upper branch being configured to operatively couple to a first marine riser, and the first outlet being in fluid communication with the lower passage of the lower trunk; and a second upper branch with a second inlet in fluid communication with a second outlet, the second upper branch being configured to operatively couple to a second marine riser, and the second outlet being in fluid communication with the lower passage of the lower trunk, such that the articulating-rotating joint is configured and located to sealingly couple the lower trunk of the Y-connector to the blowout preventer; connecting the first inlet of the Y-connector to the first marine riser; connecting the second inlet of the Y-connector to the second marine riser; and conducting first drilling, wireline, or completions operations through the first marine riser while simultaneously assembling drilling, wireline, or completions equipment in the second marine riser in preparation for second drilling operations. The method may optionally include use of any system disclosed herein, including a system employing any combination of the optional features disclosed herein.

[0009] In a fourth embodiment, a method of drilling for hydrocarbons comprises: installing a wellhead assembly on or near a sea floor; connecting a blowout preventer to the wellhead assembly; connecting the blowout preventer to an articulating-rotating joint; assembling a first marine riser operatively coupled to a drilling platform, the first marine riser comprising a first upper-marine-riser segment and a first lower-marine-riser segment connected by a first rotating-ball-joint-valve configured to operatively couple the first upper-marine-riser segment to the first lower-marine-riser segment; assembling a second marine riser operatively coupled to a drilling platform, the second marine riser comprising a second upper-marine-riser segment and a second lower-marine-riser segment connected by a second rotating-ball-joint-valve configured to operatively couple the second upper-marine-riser segment to the second lower-marine-riser segment; operatively connecting a third rotating-ball-joint-valve to join the first marine riser and the second marine riser to a blowout preventer. The method may optionally include use of any system disclosed herein, including a system employing any combination of the optional features disclosed herein.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0010] The following detailed description will be better understood when read in conjunction with the appended drawings. Shown in the drawings are various embodiments, including embodiments which may be presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS

[0011] Fig. 1 is schematic view of a dual-activity system according to the present disclosure;

[0012] Fig. 2 is an enlarged, partially schematic partial view of a first example of a Y connector for use in the dual-activity system of Fig. 1;

[0013] Fig. 3 is an enlarged, partially schematic partial longitudinal sectional view of the Y connector of Fig. 2;

[0014] Fig. 4 is an enlarged, partially schematic partial view of a second example of a Y connector for use in the dual-activity system of Fig. 1;

[0015] Fig. 5 is a sectional, partially schematic view of the gate valve of the Y connector of Fig. 4, taken along the line 5-5 in Fig. 4;

[0016] Fig. 6 is a partially schematic elevational view of a second example of a dual-activity system according to the present disclosure in a first configuration with the first marine riser 1240 in a state of increased tension and the second marine riser 1260 in a state of decreased tension;

[0017] Fig. 7 is a partially schematic elevational view of a second example of a dual-activity system according to the present disclosure in a first configuration with the first marine riser 1240 in a state of decreased tension and the second marine riser 1260 in a state of increased tension; and

[0018] Fig. 8 is a schematic view of a control system for operating components of a dualactivity system according to the present disclosure.DETAILED DESCRIPTION

[0019] Certain terminology is used in the following description for convenience only and is not limiting. The words “right,” “left,” “lower,” and “upper” designate directions in the drawings to which reference is made. The words “inner,” “inwardly,” “outer,” and “outwardly” refer to locations and directions toward and away from, respectively, the geometric center of an object and designated parts thereof. Unless specifically set forth otherwise herein, the terms “a,” “an,” and “the” are not limited to one element but instead should be read as meaning “at least one.” “At least one” may occasionally be used for clarity or readability, but such use does not change the interpretation of “a,” “an,” and “the.” Moreover, the singular includes the plural, and vice versa, unless the context clearly indicates otherwise. As used herein, the terms “proximal” and “distal” are relative terms referring to locations or elements that are closer to (proximal) or farther from (distal) with respect to other elements, the user, or designated locations. “Including” as used herein means “including but not limited to.” The word “or” is inclusive, so that “A or B” encompasses A and B,Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFSA only, and B only. The terms “about,” “approximately,” “generally,” “substantially,” and like terms used herein, when referring to a dimension or characteristic of a component, indicate that the described dimension / characteristic is not a strict boundary or parameter and does not exclude minor variations therefrom that are functionally similar. At a minimum, such references that include a numerical parameter would include variations that, using mathematical and industrial principles accepted in the art (e.g., rounding, measurement or other systematic errors, manufacturing tolerances, etc.), would not vary the least significant digit thereof.

[0020] In one aspect, referring to Figs. 1-3, a system 100 for subsea drilling, wireline, or completions operations includes a Y-connector 180 including a hollow body 182. The Y-connector 180 has a lower trunk 184 having a lower passage 186 in fluid communication with a main outlet 188. The main outlet 188 may optionally include a protective sheath 210, which may take the form of a coating or a tubular element such as a sleeve, either of which may line the main outlet 188 to protect the main outlet main outlet 188 from abrasion, wear, or other damage as items pass through main outlet 188, as well as to protect the intersection of the main outlet 188 with the first outlet 194 and second outlet 200. A first upper branch 190 has a first inlet 192 in fluid communication with a first outlet 194, the first upper branch 190 being configured to operatively couple to a first marine riser 240, and the first outlet 194 being in fluid communication with the lower passage 186 of the lower trunk 184. A second upper branch 196 has with a second inlet 198 in fluid communication with a second outlet 200, the second upper branch 196 being configured to operatively couple to a second marine riser 260, and the second outlet 200 being in fluid communication with the lower passage 186 of the lower trunk 184. An articulating-rotating joint 160 is configured to sealingly couple the lower trunk 184 of the Y-connector 180 to a blowout preventer 140. The blowout preventer 140 in turn is operatively coupled to a wellhead assembly 120 located on or near the sea floor. Note that in Fig. 1, the first marine riser 240 and the second marine riser 260 are each made up a plurality of segments, and the relative lengths of the first marine riser 240 and the second marine riser 260 and the other elements depicted throughout the drawings are not proportional to one another. Each of the first marine riser 240 and the second marine riser 260 may include a slip joint 284 for attachment to the drilling platform 280, as is known in the art.

[0021] The first embodiment of the system 100 may include any combination of optional features discussed in this paragraph. The system 100 may further include a first isolation valve 202 disposed to open and close the first inlet 192; a second isolation valve 204 disposed to open and close the secondDocket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS inlet 198; and a third isolation valve 206 disposed to open and close the main outlet 188. The first isolation valve 202, the second isolation valve 204, and the third isolation valve 206 may be used to open and close paths for fluids and equipment leading from the first marine riser 240 and the second marine riser 260 to the articulating-rotating joint 160, and ultimately to the blowout preventer 140 and the wellhead assembly 120, so only one of the first marine riser 240 and the second marine riser 260 may connected with an open path to the blowout preventer 140 and the wellhead assembly 120 at a given time. The system may include the Y-connector 180 being configured to sealingly couple a selected one of the first upper branch 190 or the second upper branch 196 in fluid communication with the lower trunk 184. The articulating-rotating joint 160 may include a ball joint a spherical roller bearing (or similar) and packing elements, or a rotary seal to form a rotating-articulating joint. In the illustrated embodiment, the articulating-rotating joint 160 may include a housing 162 and a ball body 164 seated within the housing 162 for articulation and rotation with respect to the housing 162, wherein the ball body 164 is sealingly engaged with the housing 162 so that the articulating-rotating joint 160 provides a sealed connection joining the main outlet 188 of the Y-connector 180 to the blowout preventer 140. The ball body 164 may include an outlet 166 for sealingly engaging the outlet 166 with the blowout preventer 140. The system 100 may further include a seal 170 disposed between the housing 162 and the ball body 164.

[0022] Referring to Figs. 6-7, a subsea connector 340 may be provided to allow for hydraulic and / or electronic connection to an input device, including but not limited to a hydraulic or electrical connector or a remotely operated vehicle (ROV). A subsea connector 340 may also be incorporated into the system 100 of Fig. 1 by placing the subsea connector 340 in the system 100 in a location analogous to that shown in Figs. 6-7.

[0023] The system 100 of Fig. 1 may include an alternative Y-connector 1180, as shown in Figs. 4 and 5. The Y-connector 1180 may include a first upper branch 1190, a second upper branch 1196 and a main outlet 1188. The first upper branch 1190 may have a first inlet 1192 and a first outlet 1194, and the second upper branch 1196 may have a second inlet 1198 and a second outlet 1200. The alternative Y-connector 1180 may further include a gate valve 1400 having a closure body 1402 movable by an actuator 1404. The closure body 1402 may be movable between a first position opening a path between the first inlet 1192 and the main outlet 1188 by aligning a first aperture 1406 in the closure body 1402 with the first upper branch 1190, and a second position opening a path between the second inlet 1198 and the main outlet 1188 by aligning the closure body 1402 with aDocket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS second opening 1406 in the closure body 1402. The first position of the closure body may close the path between the second inlet 1198 and main outlet 1188; and the second position of the closure body may close the path between the first inlet 1192 and the main outlet 1188. The closure body may take the form of a gate valve 1400 or similar components. The illustrated gate valve 1400 has a closure body 1402 selectably movable to block the first upper branch 1190 or the second upper branch 1196 and positioned by a actuator 1404. The actuator 1404 may by operatively connected to a controller 320, which may be as further described below. Note that although Fig. 4 shows the gate valve 1400 along with a first isolation valve 1202, a second isolation valve 1204, and a third isolation valve 1206, the gate valve 1400 may be used while omitting at least the first isolation valve 1202, the second isolation valve 1204, and the third isolation valve 1206.

[0024] The system 100 may further include a lubricator 300 operatively coupled to lubricate the articulating-rotating joint 160. The lubricator 300 may include an oil or grease reservoir with an accumulator or compensation system to provide lubrication to the articulating-rotating joint 160. The accumulator or compensation system of the lubricator 300 may be configured to compensate for a loss of lubrication due to usage and / or the water depth at which the equipment is operating. The lubricator 300 may have or be operatively connected to sensors for determining, for example, depth, level, pressure, or weight of lubricant, which may indicate the level of lubrication used or consumed and therefore the level of lubrication available in the reservoir of the lubricator 300. The lubricator 300 or the connected sensors may be operatively connected to trigger one or more alarms to alert an operator of the lubricator to the level of lubrication and / or a loss of lubrication.

[0025] Referring to Figs. 6-7, in a second embodiment, a system 1100 for subsea drilling, wireline, or completions operations may include a first marine riser 1240 configured to be operatively coupled to a drilling platform 1280, which is equipped with two derricks 282, and a second marine riser 1260 configured to be operatively coupled to the drilling platform 1280. The first marine riser 1240 includes a first upper-riser segment 1242 and a first lower-riser segment 1244; the second marine riser 1260 includes a second upper-riser segment 1262 and a second lower-riser segment 1264. A third rotating-ball-joint-valve 1162 operatively connects the first marine riser 1240, and in particular the first lower-riser segment 1244, to the swivel body 1340. The third rotating-ball -joint- valve 1162 also operatively connects the second marine-riser 1260, and in particular the lower-riser segment 1264, to the swivel body 1340.Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS

[0026] A first rotating-ball-joint-valve 1160 connects the first upper-riser segment 1242 to the first lower-riser segment 1244, such that the first upper-riser segment 1242 may rotate or articulate with respect to the first lower-riser segment 1244. Moreover, the first rotating-ball-joint-valve 1160 may be configured to operate as a valve so that when the first upper-riser segment 1242 is aligned with the first lower-riser segment 1244 as shown in Fig. 7, a path is open between first marine riser 1240 and the blowout preventer 140. A second rotating-ball-joint-valve 1160 connects the second upper-riser segment 1262 to the second lower-riser segment 1264, such that the second upper-riser segment 1262 may rotate or articulate with respect to the first lower-riser segment 1264. Moreover, the second rotating-ball-joint-valve 1160 may be configured to operate as a valve so that when the second upper-riser segment 1262 is aligned with the second lower-riser segment 1264 as shown in Fig. 6, a path is open between second marine riser 1260 and the blowout preventer 140.

[0027] Continuing to refer to Figs. 6 and 7, each of the first marine riser 1240 and the second marine riser 1260 has tension device such as a tension ring 1250 operatively attached to the respective first upper-riser segment 1242 or second upper-riser segment 1262 thereof. The tension ring 1250 in each case at least one tension member 1252 attached thereto (two are shown) in a manner known to those of skill in the art. The tension members 1252 act on each tension ring 1250 to retract or release a selected one of the first marine riser 1240 or the second marine riser 1260 to place the selected one of the first marine riser 1240 or the second marine riser 1260 in tension, in turn resulting in the changes of configuration and alignment described above and shown in Figs. 6 and 7. That is, a tension ring 1250, the tension ring 1250 having at least one tension member 1252 attached thereto, is operatively attached to the first marine riser 1240 and configured to place the first marine riser 1240 selectively in a state of increased or decreased tension. A second tension ring 1250, with at least one tension member 1252 attached thereto, is operatively attached to the second marine riser 1260 and configured to place the second marine riser 1260 selectively in a state of increased or decreased tension.

[0028] Note that in Figs. 6-7, the first marine riser 1240, the second marine riser 1260, first upperriser segment 1242, first lower-riser segment 1244, second upper-riser segment 1262, and second lower-riser segment 1264 each may be made up a plurality of segments, as is known in the art. Moreover, the relative lengths of the first marine riser 1240 and the second marine riser 1260 and the other elements depicted throughout the drawings are not shown proportionally to one another; for example, the first marine riser 1240 and the second marine riser 1260 are proportionally far longer than the proportions shown. Each of the first marine riser 1240 and the second marine riser 1260 mayDocket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS include a slip joint 284 (as shown in the system 100 of Fig. 1) for attachment to the drilling platform 1280, as is known in the art.

[0029] In certain embodiments, the system 1100 may provide a second rotation path to the drilling platform 1280 in case the swivel body 1340 happens to fail. Each first upper-riser segment 1242 and second upper-riser segment 1262 would be held in tension by a tensioner ring 1250 and connected to the drilling platform 1280 by slip joint 284 (see Fig. 1). The rotating-ball -joint- valve 1162 is also able to pivot around its vertical axis (same as first marine riser 1240 in tension or second marine riser 1260 in tension) and that rotation would allow the drilling platform 1280 to rotate.

[0030] The system 1100 may include any combination of optional features discussed in this paragraph. At least one of the first rotatingjoint 1160, the second rotating joint 1160, the first rotatingball -joint- valve 1160, may be configured for articulation as well as rotation. For example, at least one of the first rotating j oint 1160, the second rotating j oint 1160, the first rotating-ball-joint-valve 1160, or the second rotating-ball-joint valve 1160 may have a structure of the type disclosed with respect to the articulating-rotating joint 160.

[0031] In use, the system 100 may facilitate a method of drilling or well construction for hydrocarbons including the following steps: installing a wellhead assembly 120 on or near a sea floor; connecting a blowout preventer 140 to the wellhead assembly 120; connecting the blowout preventer to an articulating-rotating joint 160; connecting a Y-connector 180 to the articulating-rotating joint 160, the Y-connector 180 having: a lower trunk 184 having a lower passage 186 in fluid communication with a main outlet 188; a first upper branch 190 with a first inlet 192 in fluid communication with a first outlet 194, the first upper branch 190 being configured to operatively couple to a first marine riser 240, and the first outlet 194 being in fluid communication with the lower passage 186 of the lower trunk 184; and a second upper branch 196 with a second inlet 198 in fluid communication with a second outlet 200, the second upper branch 196 being configured to operatively couple to a second marine riser 260, and the second outlet 200 being in fluid communication with the lower passage 186 of the lower trunk 184, such that the articulating-rotating joint 160 is configured and located to sealingly couple the lower trunk 184 of the Y-connector 180 to the blowout preventer; connecting the first inlet 192 of the Y-connector to the first marine riser 240; connecting the second inlet 198 of the Y-connector to the second marine riser 260; and conducting first drilling wireline, or completions operations through the first marine riser 240 while simultaneously assembling drilling, wireline, or completions equipment in the second marine riser 260 in preparation for second drilling,Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS wireline, or completions operations (or subsequent drilling, wireline, or completions operations). The method may optionally include use of any system disclosed herein, including a system employing any combination of the optional features disclosed herein.

[0032] The Y-connector 180, the housing 162 and the ball body 164 of the articulating-rotating joint 160, the swivel body 1340, the first rotating joint 1160, the second rotating joint 1160, the first rotating-ball-joint-valve 1160, or the fourth-rotating joint 1160, the first upper-riser segment 1242, the first lower-riser segment 1244, the second upper-riser segment 1262, and the second lower-riser segment 1264 and other components of the systems may be formed from a strong, corrosion-resistant materials such as composites (including composites having carbon fiber), polymers, non-metallics, metallics (including but not limited to low carbon steel) which may be protected by a suitable coating. The first rotating-ball-joint-valve 1 160, or the fourth-rotating joint 1 160, the first upper-riser segment 1242, the first lower-riser segment 1244, the second upper-riser segment 1262, and the second lower- riser segment 1264 may be formed of elastic material such as polymers or composites, which may be selected so that longitudinal elastic deformation of the first rotating-ball-joint-valve 1160, or the fourth-rotating joint 1160, the first upper-riser segment 1242, the first lower-riser segment 1244, the second upper-riser segment 1262, and the second lower-riser segment 1264 may constitute a lengthcompensation mechanism. The seal 170 may be formed from durable sealing material such as rubber, polyurethane, silicone, metal, elastomer or composites. Other components, such as the wellhead assembly 120, the blowout preventer 140, the first isolation valve 202, the second isolation valve 204, the third isolation valve 206, the first marine riser 240, the second marine riser 260, the drilling platform 280, 1280, the controller 320, and other components are made from materials generally known to those of skill in the art.

[0033] Referring to Fig. 8, the system 100 may further include a controller 320 operatively coupled to at least one of the blowout preventer, the lubricator 300, the first isolation valve 202, the second isolation valve 204, the third isolation valve 206, or the actuator 1404 of the gate valve 1400 (Figs. 4 and 5). The controller 320

[0034] With respect to the methods and processes described herein, those skilled in the art will recognize that boundaries between the above-described operations are merely illustrative. The multiple operations may be combined into a single operation, a single operation may be distributed in additional operations and operations may be executed at least partially overlapping in time.Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFSFurther, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be altered in various other embodiments.

[0035] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present disclosure.

Claims

1. Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFSCLAIMSWe claim:

1. A system for subsea well construction or drilling, the system comprising: a Y-connector comprising a hollow body, the Y-connector having: a lower trunk having a lower passage in fluid communication with a main outlet; a first upper branch with a first inlet in fluid communication with a first outlet, the first upper branch being configured to operatively couple to a first marine riser, and the first outlet being in fluid communication with the lower passage of the lower trunk; and a second upper branch with a second inlet in fluid communication with a second outlet, the second upper branch being configured to operatively couple to a second marine riser, and the second outlet being in fluid communication with the lower passage of the lower trunk; and an articulating-rotating joint configured to sealingly couple the lower trunk of the Y- connector to a blowout preventer.

2. The system according to claim 1, further comprising: a first isolation valve disposed between the first inlet and the first outlet; a second isolation valve disposed between the second inlet and the second outlet; and a third isolation valve disposed between the lower trunk and the main outlet.

3. The system according to claim 1 or claim 2, wherein the Y-connector is configured to sealingly couple a selected one of the first upper branch or the second upper branch in fluid communication with the lower trunk.

4. The system according to any one of claims 1 through 3, wherein the articulating-rotating joint comprises a ball joint.

5. The system according to any one of claims 1 through 3, wherein the articulating-rotating joint comprises: a housing; andDocket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS a ball body seated within the housing for articulation and rotation with respect to the housing, wherein the ball body is sealingly engaged with the housing so that the articulating-rotating joint provides a sealed connection joining the main outlet of the Y-connector to the blowout preventer.

6. The system according to claim 5, further comprising a seal disposed between the housing and the ball body.

7. The system according to claim 6, wherein the articulating-rotating joint comprises a spherical roller bearing and packing-sealing elements.

8. The system according to claim 6, wherein the articulating-rotating joint comprises a rotary seal.

9. The system according to claim 3, further comprising a closure body movable between: a first position opening a path between the first inlet and main outlet; and a second position opening a path between the second inlet and the main outlet.

10. The system according to claim 9, wherein: the first position closes the path between the second inlet and main outlet; and a second position closes a path between the first inlet and the main outlet.

11. The system according to any one of claims 1-10, further comprising a lubricator operatively coupled to lubricate the articulating-rotating joint.

12. The system according to claim 11, further comprising a controller operatively coupled to at least one of the blowout preventer, the lubricator, the first isolation valve, the second isolation valve, or the third isolation valve.

13. A system for subsea drilling, the system comprising: a first marine riser configured to be operatively coupled to a drilling platform, the first marine riser comprising a first upper-riser segment and a first lower-riser segment; a second marine riser configured to be operatively coupled to the drilling platform, the second marine riser comprising a second upper-riser segment and a second lower-riser segment;Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS a first rotating-ball -joint-valve configured to operatively couple the first upper-riser segment to the first lower-riser segment; a second rotating-ball-joint-valve configured to operatively couple the second upper-riser segment to the second lower-riser segment; and a third rotating-ball -joint-valve operatively first marine riser and the second marine riser to a blowout preventer.

14. The system according to claim 13, further comprising a swivel connector disposed between the third rotating-ball-joint- valve and the blowout preventer.

15. The system according to claim 13 or claim 14, further comprising a tension ring with at least one tension member attached thereto, operatively attached to the first marine riser, and configured to place the first marine riser selectively in a state of increased or decreased tension; and a second tension ring with at least one tension member attached thereto, operatively attached to the second marine riser, and configured to place the second marine riser selectively in a state of increased or decreased tension.

16. A method of drilling for hydrocarbons, comprising: installing a wellhead assembly on or near a sea floor; connecting a blowout preventer to the wellhead assembly; connecting the blowout preventer to an articulating-rotating joint; connecting a Y-connector to the articulating-rotating joint, the Y-connector having: a lower trunk having a lower passage in fluid communication with a main outlet; a first upper branch with a first inlet in fluid communication with a first outlet, the first upper branch being configured to operatively couple to a first marine riser, and the first outlet being in fluid communication with the lower passage of the lower trunk; and a second upper branch with a second inlet in fluid communication with a second outlet, the second upper branch being configured to operatively couple to a second marine riser, and the second outlet being in fluid communication with the lower passage of the lower trunk,Docket No. 689764.0067 / 67WO (TOFF-067 / OOWO)FILED VIA EFS such that the articulating-rotating joint is configured and located to sealingly couple the lower trunk of the Y-connector to the blowout preventer; connecting the first inlet of the Y-connector to the first marine riser; connecting the second inlet of the Y-connector to the second marine riser; and conducting first drilling, wireline, or completions operations through the first marine riser while simultaneously assembling drilling, wireline, or completions equipment in the second marine riser in preparation for second drilling, wireline, or completions operations.

17. A method of drilling for hydrocarbons according to claim 16, wherein the method comprises using of a system according to any one of claims 1-12.

18. A method of drilling for hydrocarbons, comprising: installing a wellhead assembly on or near a sea floor; connecting a blowout preventer to the wellhead assembly; connecting the blowout preventer to an articulating-rotating joint; assembling a first marine riser operatively coupled to a drilling platform, the first marine riser comprising a first upper-riser segment and a first lower-riser segment connected by a first rotating-ball-joint-valve configured to operatively couple the first upper-riser segment to the first lower-riser segment; assembling a second marine riser operatively coupled to a drilling platform, the second marine riser comprising a second upper-riser segment and a second lower-riser segment connected by a second rotating-ball-joint-valve configured to operatively couple the second upper-riser segment to the second lower-riser segment; operatively connecting a third rotating-ball-joint-valve to join the first marine riser and the second marine riser to a blowout preventer; and conducting first drilling, wireline, or completions operations through the first marine riser while simultaneously assembling drilling, wireline, or completions equipment in the second marine riser in preparation for second drilling, wireline, or completions operations.

19. A method of drilling for hydrocarbons according to claim 18, wherein the method comprises using of a system according to any one of claims 13-15.

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