Patent Publication Number: US-10767433-B2

Title: Integrated controls for subsea landing string, blow out preventer, lower marine riser package

Description:
BACKGROUND 
     A subsea well intervention system typically employs equipment such as a blowout preventer (BOP) stack, a subsea landing string (SSLS), and a lower marine riser package (LMRP). These components cooperate together to maintain pressure control and enable access to the subsea well. Operating these components together presents certain challenges and complexities. Conventionally controls to these components are independent and have redundant functionality, and are therefore inefficient. 
     SUMMARY 
     Embodiments of the present disclosure are directed to a system including a subsea landing string, blow out preventer, and a lower marine riser package coupled to a wellhead system on a seabed. The system includes a controls module located between the BOP stack below and the LMRP above to provide coupling of the BOP and LMRP controls through the drill through column to the SLSS controls. The controls module has an input line, a second input line component, and a coupling mechanism. The coupling mechanism is configured to couple the first input line component to the second input line component. The one or more actuatable components in the BOP and the LMRP are configured to receive an input from the input line in the controls module. The actuatable components of the SLSS is configured to receive an input from the second line component via the coupling mechanism. 
     Further embodiments of the present disclosure are directed to a controls module including a plurality of ports configured to couple with corresponding ports on a subsea landing string on a wellhead. The ports are coupled to input lines operably coupled to a remote control device such as surface controls or a rig. The input lines are configured to provide control inputs for at least one of a blowout preventer (BOP) stack and a lower marine riser package (LMRP). 
     Still further embodiments of the present disclosure are directed to a method of installing and operating a subsea landing string. The method includes installing a lower marine riser package (LMRP) onto a blowout preventer (BOP) stack, the controls module having an input line and a coupling mechanism. The subsea landing string has one or more input ports. The method also includes actuating the coupling mechanism to couple the input line to the ports. The ports are operably coupled to components within the subsea landing string. The method further includes operating the components via the input line and the ports. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  illustrates an assembly including a subsea landing string (SSLS) and, a BOP stack, and an LMRP according to the prior art. 
         FIG. 2  illustrates a controls module for use with a BOP, LMRP, and an SLSS according to embodiments of the present disclosure. 
         FIG. 3  is a schematic illustration of a controls module according to embodiments of the present disclosure. 
         FIG. 4  illustrates the controls module in a deployed configuration according to embodiments of the present disclosure. 
         FIG. 5  is an illustration of an embodiment of the controls module including access via a Remotely Operated Vehicle (ROV) according to embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Below is a detailed description according to various embodiments of the present disclosure. Throughout this disclosure, relative terms such as above or below generally refer to an orientation relative to a subsea surface but are not to be construed in a limiting manner.  FIG. 1  illustrates an assembly  10  including a subsea landing string  12 , a BOP stack  14  and a LMRP  16  coupled to the BOP stack  14  and the subsea landing string  12  according to the prior art. The assembly  10  is coupled to the wellhead  18  which can be on the ocean floor  20 . The BOP stack  14  is generally installed complete with the LMRP  16 . The BOP  14  and the SSLS  12  each can require controls via electronic, hydraulic, or electrohydraulic lines to operate valves, rams, and other equipment. The controls for the BOP  14  and the SSLS  12  are redundant and introduce complexity to the system. The controls for the BOP  14  are independent of the controls for the SLSS  12  and therefore when the full intervention system is installed there are two sets of control lines from the remote control device. 
       FIG. 2  illustrates an assembly  19  including a controls module  22  for use with SSLS  12 , a BOP  14 , and an LMRP  16  according to embodiments of the present disclosure. The controls module  22  can be installed between the BOP  14  and the LMRP  16 . In some embodiments the controls module  22  is a separate component which can be installed onto the BOP  14  or onto the LMRP  16 . It can be deployed with the BOP  14 , or independently before the LMRP  16  is installed. In other embodiments the controls module  22  is integrated with the BOP  14  or with the LMRP  16 . The LMRP  16  includes control pods that provide hydraulic, electrical, or combination hydro-electrical controls to the BOP  14 . Once the controls module  22  is fully installed it will operate with the BOP  14 , LMRP  16 , and SLSS  12  in the ways described herein. 
       FIG. 3  is a schematic illustration of a controls module  22  according to embodiments of the present disclosure. The controls module  22  is configured to operate with an annular BOP  24  above and a shear ram  26  below. The controls module  22  is coupled to a subsea landing string (SSLS)  12  and is shown with two halves, one on either side of the SSLS  12 . In some embodiments the two halves of the controls module  22  are identical. In other embodiments there can be differences between the halves of the controls module  22  as needed or convenient for a given installation. The SSLS  12  includes one or more control ports such as hydraulic  28 , power  30 , or communication  32 . These are collectively referred to herein as ports without loss of generality and in a non-limiting way. The ports are coupled to corresponding lines  28   b ,  30   b , and  32   b  which are coupled to a remote control system such as surface controls or a rig. In some embodiments there can be any combination of one, two, or all three types of ports. Furthermore, the orientation and configuration of the ports can vary in a given installation. The ports can be used for any control input needed in the form of hydraulic, electronic, or combination electro-hydraulic (known as MUX control) systems. Unlike conventional systems which typically require separate hydraulic, power and/or communication lines for the SSLS  12  run internally within the drill through column and the BOP stack  14 /LMRP  16  run external to the drill through column, this present disclosure enables the use of fewer hydraulic, power and/or communication lines running to the seabed by piggy-backing SSLS  12  control conduits onto existing BOP  14 /LMRP  16  control conduits. 
     The controls module  22  includes complementary ports  28   a ,  30   a , and  32   a  which are configured to couple to their counterparts  28 ,  30 , and  32 , respectively. The controls module  22  also includes a coupling mechanism  34  configured to actuate to couple the ports together. In some embodiments the coupling mechanism  34  includes a piston  36  and an actuation component such as a hydraulic control line having an engage line  38  and a disengage line  40 . The actuating mechanism  34  can be a screw or a magnetically-actuated mechanism or any other suitable mechanical equivalent. The engage line  38  when actuated imparts pressure to the piston  36  to move the ports  28   a ,  30   a , and  32   a  toward their counterpart ports  28 ,  30 , and  32  to couple the lines. The coupling mechanism  34  can also include a second disengage line  42  that can be configured as an emergency disengage line  42  that can have a comparatively higher pressure rating and can be operated in concert with emergency procedures and in response to detecting a failure condition. The disengage line  42  can be a “fail open” system under which in the absence of a signal (electronic, mechanical, or hydraulic) the disengage line  42  actuates to uncouple the ports to release the controls module  22 . In other embodiments the disengage line  42  can be a “fail closed” system. 
     In some embodiments the hydraulic line  28   b  can be coupled to the engage line  38 , the disengage line  40 , or both via a line  29 . With this configuration a single hydraulic line can control coupling and uncoupling the ports, as well as provide the hydraulic input for the ports  28  and  28   a . The controls module  22  can include a mini-indexer or another suitable mechanism to distribute hydraulic inputs whereby a single hydraulic input can actuate multiple outputs. In further embodiments the power line  30   b  can be coupled via an electric line  31  to the coupling mechanism  34  which can be electrically actuated to couple or uncouple the ports. In other embodiment the communication line  32   b  can also be used to perform the same task. 
     The ports couple together using a variety of different coupling mechanisms, some mechanical, some electrical, some hydraulic. Even among these categories there can be different couplers. For example, a hydraulic line can be coupled via a hydraulic line wet mate (HLWM) provided by SCHLUMBERGER and shown in U.S. Pat. No. 8,061,430. An electrical connection such as for power, communications, or both power and communications can be made using an inductive coupler  44  similar to the inductive coupler provided by SCHLUMBERGER and shown in U.S. Pat. No. 5,971,072. Other mechanical, hydraulic and electric port couplings are compatible with the systems and methods of the present disclosure. 
       FIG. 4  illustrates the controls module  22  in a deployed configuration according to embodiments of the present disclosure. In operation, the BOP  14  and SSLS  12  (shown to greater advantage in  FIG. 2 ) are installed at the wellhead on the subsea surface with the ports in an accessible but protected position. The controls module  22  can be lowered into position with the ports  28   a ,  30   a , and  32   a  being maneuvered relative to their counterpart ports  28 ,  30 , and  32  on the SSLS  12 . Once the controls module  22  is properly positioned, the coupling mechanism  34  can be actuated to couple the ports  28 ,  30 , and  32  to ports  28   a ,  30   a , and  32   a  to complete the connection between the SSLS  12  and the rig or other controller above. 
     In some embodiments the SSLS  12  can include any suitable number of ports.  FIGS. 3 and 4  show three ports: one hydraulic  28 , one for power  30 , and one for communication  32 . It is to be appreciated that there can be any number of each of these types of ports. In some embodiments there are only one sort. In some embodiments these various ports can be coupled to their counterpart port independently of the other ports and the coupling mechanism  34  will be configured to support this coupling. For example, the coupling mechanism  34  can comprise a plurality of pistons  50 ,  52 , and  54 , one for each port. Each piston can be actuated independently to couple (or uncouple) one or more of the ports while leaving other ports uncoupled (or coupled). 
       FIG. 5  is an illustration of an embodiment of the controls module  22  including access via a Remotely Operated Vehicle (ROV)  60  according to embodiments of the present disclosure. An ROV  60  can be deployed to initiate or terminate a coupling between ports in the controls module  22 . The controls module  22  can include access means for the ROV  60 . In some embodiments the access means is an external port  62  on the controls module  22  through which the ROV  60  can reach the ports  28   a ,  30   a , and  32   a . In some embodiments the ROV  60  is capable or initiating the coupling mechanism  34 , or can provide power to initiate a coupling between ports. In some embodiments the controls module  22  can include an externally-actuatable device  64  such as a rotatable wheel. The device  64  can be a switch, a lever, or any other suitable manipulatable device that an ROV can access using an arm  66 . In the case that the device  64  is rotatable, the device  64  can be connected to a threaded internal component that causes the ports to couple under power of the rotation. The foregoing disclosure hereby enables a person of ordinary skill in the art to make and use the disclosed systems without undue experimentation. Certain examples are given to for purposes of explanation and are not given in a limiting manner.