Abstract: A monitoring system for use in a marine riser system coupled to a rig vessel includes one or more subsea inertial measurement units adapted for mounting to a lower end of a riser, an LMRP, or both. The one or more subsea inertial measurement units may acquire time series data of inclination and acceleration. The one or more subsea inertial measurement units may transmit, to a vessel transceiver, frequency data computed from the time series data, low-pass filtered values of the time series data, or both. The monitoring system includes a surface processing unit that is in communication with the vessel transceiver. The surface processing unit may be programmed to compute, for example, fatigue along the marine riser system, the difference between the inclination of the lower end of the riser and the inclination of the LMRP, or both, by applying predetermined functions to the transmitted data.

Abstract: A surface joint provides a sealing interface between pipe rams or variable-bore rams of a surface blowout preventer and a landing string. The surface joint may be used in a system including the surface blowout preventer, a subsea mudline closure device having a conventional configuration without additional pipe rams or variable-bore rams used to close on a slip joint, and a high-pressure riser.

Abstract: For completing a well, and for performing workover or intervention operations with the well, a surface BOP stack is coupled to the subsea wellhead or a subsea tree via a high pressure riser. The well is completed or the workover or intervention operations are performed through the surface BOP stack.

Abstract: Hang-off and/or torque 1 features are provided on the pipes and/or the connections of a high-pressure riser. The hang-off features may be useful to support the weight of the full length of the riser. Accordingly, the hang-off may be done directly in the middle of the connection, where the strength is the greatest. Also, by using the torque features, it is possible to accommodate large torque values. Accordingly, a large torque resistance may be provided while an upper pipe is being made up. A make-up tool taking advantage of the hang-off and/or torque features permits assembling the high-pressure riser more automatically and with less manual intensive labor.

Abstract: A repair axial bearing system includes an arcuate rail coupled to a support, one or more bolts protruding upward from a raised portion coupled to a supported member, and a lever plate including at least one low friction bearing pad mounted in the lever plate. A first new bearing surface is formed on the arcuate rail. A second new bearing surface is formed on the at least one low friction bearing pad. The one or more bolts are tensioned with bolt tensioners to press the lever plate against the raised portion. The axial bearing system can include a hydraulic cylinder to slide the second bearing surface over the first bearing surface. The repair axial bearing system can be used to supplant a damaged axial bearing positioned between an FPSO and a turret.

Abstract: A marine riser having a pressure level rating of twenty ksi or more includes riser tubulars and auxiliary lines that are made of steel having an API grade C110 and C125 and is NACE certified. The riser tubulars and auxiliary lines are not welded, but are assembled via threaded, clamped, stabbed or other mechanical and/or hydraulic connections. Some of the connections may be pre-assembled to reduce assembly time on the drill ship.

Abstract: A monitoring system for use in a marine riser system coupled to a rig vessel includes one or more subsea inertial measurement units adapted for mounting to a lower end of a riser, an LMRP, or both. The one or more subsea inertial measurement units may acquire time series data of inclination and acceleration. The one or more subsea inertial measurement units may transmit, to a vessel transceiver, frequency data computed from the time series data, low-pass filtered values of the time series data, or both. The monitoring system includes a surface processing unit that is in communication with the vessel transceiver. The surface processing unit may be programmed to compute, for example, fatigue along the marine riser system, the difference between the inclination of the lower end of the riser and the inclination of the LMRP, or both, by applying predetermined functions to the transmitted data.

Abstract: A system for tethering a subsea blowout preventer (BOP) includes a plurality of anchors disposed about the subsea BOP and secured to the sea floor, a plurality of tensioning systems, and a plurality of flexible tension members. Each tensioning system is coupled to a frame of the BOP and is configured to apply a tensile preload to one of the tension members. Each tension member is coupled to one of the anchors and extends from a first end coupled to one of the tensioning systems to a second end coupled to an anchor.

Abstract: A mudline closure device is lowered between tensioners coupled to a deck of a vessel or rig onto a subsea wellhead. A tensioner platform is then attached to the tensioners. The tensioner platform includes a platform opening having an inner diameter through which an emergency disconnect system may pass. The tensioner platform also includes rotation bearings secured in the platform opening. A split support includes outer surfaces disposed along its circumference. The outer surfaces are seated on the rotation bearings. The split support includes a support opening having an inner diameter through which a marine riser may pass. The split support also includes a landing shoulder secured in the support opening to suspend a surface blowout preventer to the deck. As the vessel or rig changes direction, the split support rotates relative to the tensioner platform without imparting excessive torsion on the marine riser.

Abstract: Hang-off and/or torque 1 features are provided on the pipes and/or the connections of a high-pressure riser. The hang-off features may be useful to support the weight of the full length of the riser. Accordingly, the hang-off may be done directly in the middle of the connection, where the strength is the greatest. Also, by using the torque features, it is possible to accommodate large torque values. Accordingly, a large torque resistance may be provided while an upper pipe is being made up. A make-up tool taking advantage of the hang-off and/or torque features permits assembling the high-pressure riser more automatically and with less manual intensive labor.

Abstract: A tethering system includes an adapter configured to couple to an upper end of a subsea anchor, a tensioning system, and a flexible tension member having one end coupled to the tensioning system and the other end coupled to the adapter. The tensioning system is operable to pay in and pay out the flexible tension member relative to the tensioning system. The tensioning system can be mounted to the BOP frame, and tension can be applied via a locally or remotely placed winch assembly. Tension can also be applied by gripping the flexible tension member and pulling on the flexible tension member with a hydraulic cylinder.

Abstract: For completing a well, and for performing workover or intervention operations with the well, a surface BOP stack is coupled to the subsea wellhead or a subsea tree via a high pressure riser. The well is completed or the workover or intervention operations are performed through the surface BOP stack.

Abstract: A surface joint provides a sealing interface between pipe rams or variable-bore rams of a surface blowout preventer and a landing string. The surface joint may be used in a system including the surface blowout preventer, a subsea mudline closure device having a conventional configuration without additional pipe rams or variable-bore rams used to close on a slip joint, and a high-pressure riser.

Abstract: A repair axial bearing system includes an arcuate rail coupled to a support, one or more bolts protruding upward from a raised portion coupled to a supported member, and a lever plate including at least one low friction bearing pad mounted in the lever plate. A first new bearing surface is formed on the arcuate rail. A second new bearing surface is formed on the at least one low friction bearing pad. The one or more bolts are tensioned with bolt tensioners to press the lever plate against the raised portion. The axial bearing system can include a hydraulic cylinder to slide the second bearing surface over the first bearing surface. The repair axial bearing system can be used to supplant a damaged axial bearing positioned between an FPSO and a turret.

Abstract: A system for tethering a subsea blowout preventer (BOP) includes a plurality of anchors disposed about the subsea BOP and secured to the sea floor, a plurality of tensioning systems, and a plurality of flexible tension members. Each tensioning system is coupled to a frame of the BOP and is configured to apply a tensile preload to one of the tension members. Each tension member is coupled to one of the anchors and extends from a first end coupled to one of the tensioning systems to a second end coupled to an anchor.

Abstract: A pile top assembly includes an adapter configured to couple to an upper end of a subsea anchor, a tensioning system mounted on an upper end of the adapter, and a flexible tension member having a first end coupled to the tensioning system. The tensioning system is operable to pay in and pay out the flexible tension member relative to the tensioning system. The pile top assembly further includes means coupled to the adapter for selectively engaging the upper end of the subsea anchor.

Abstract: An early production system includes an Emergency Disconnect Package (“EDP”), a production riser coupled between the EDP and a sea surface processing facility, a gas export tubing coupled between the EDP and the sea surface processing facility, and a flow base. The flow base is detachably connectable to the EDP. The flow base also includes an Independent Production Control System (“IPCS”) for controlling at least one production valve.

Abstract: An early production system includes an Emergency Disconnect Package (“EDP”), a production riser coupled between the EDP and a sea surface processing facility, a gas export tubing coupled between the EDP and the sea surface processing facility, and a flow base. The flow base is detachably connectable to the EDP. The flow base also includes an Independent Production Control System (“IPCS”) for controlling at least one production valve.

Abstract: A pile top assembly includes an adapter configured to couple to an upper end of a subsea anchor, a tensioning system mounted on an upper end of the adapter, and a flexible tension member having a first end coupled to the tensioning system. The tensioning system is operable to pay in and pay out the flexible tension member relative to the tensioning system. The pile top assembly further includes means coupled to the adapter for selectively engaging the upper end of the subsea anchor.

Abstract: An early production system includes an Emergency Disconnect Package (“EDP”), a production riser coupled between the EDP and a sea surface processing facility, a gas export tubing coupled between the EDP and the sea surface processing facility, and a flow base. The flow base is detachably connectable to the EDP. The flow base also includes an Independent Production Control System (“IPCS”) for controlling at least one production valve.