Offshore turret upper bearing

An offshore system which includes a vessel hull that floats in a sea and that can weathervane and that forms a vertical opening, a turret that lies in said opening, a mooring structure that extends from said turret to the seafloor, and a bearing structure that rotatably supports said turret on said vessel and that includes an upper bearing assembly, wherein:

• said upper bearing assembly includes upper and lower bearings that lie facewise adjacent at an interface, with the upper bearing connected to said turret and the lower bearing supported on said hull;
• and including
• a source of pressured lubricant coupled to said interface;
• a sensor that senses when said hull is rotating and when said hull is not rotating, relative to said turret:
• said sensor being connected to said source to control said source to apply pressured lubricant to said interface when said hull is rotating relative to the seafloor and to not apply pressured lubricant to said interface when said hull is not rotating.

An offshore system which includes a vessel hull that floats in a sea and that can weathervane and that forms a vertical opening, a turret that lies in said opening, a mooring structure that extends from said turret to the seafloor, and a bearing structure that rotatably supports said turret on said vessel and that includes an upper bearing assembly, wherein:

• said upper bearing assembly includes upper and lower bearings that lie facewise adjacent at an interface, with the upper bearing connected to said turret and the lower bearing supported on said hull;
• and including
• a source of pressured lubricant coupled to said interface;
• a sensor which senses when said lower bearing is about to turn relative to said upper bearing after not turning, and which is connected to said source, and which controls said source to time modulate the pressure of said fluid applied to said interface, when said upper bearing is about to turn.

An offshore system which includes a vessel hull that floats in a sea and that can weathervane and that forms a vertical opening, a turret that lies in said opening, a mooring structure that extends from said turret to the seafloor, and a bearing structure that rotatably supports said turret on said vessel and that includes an upper bearing assembly, wherein:

• said upper bearing assembly includes upper and lower slider bearing rings that lie facewise adjacent at an interface, with the upper bearing ring connected to said turret and the lower bearing ring supported on said hull;
• and including
• a source of pressured lubricant coupled to said interface;
• said system is devoid of a holdown bearing device that would prevent lift off of one side of said upper slider bearing ring relative to said lower bearing ring when an upper portion of said turret tilts;
• said upper bearing assembly includes means for enabling the escape of pressured lubricant primarily only from a side of said interface when said upper slider bearing ring lifts up off said lower slider bearing ring during tilt of said turret.

An offshore system which includes a vessel hull that floats in a sea and that can weathervane and that forms a vertical opening, a turret that lies in said opening, a mooring structure that extends from said turret to the seafloor, and a bearing structure that rotatably supports said turret on said vessel and that includes an upper bearing assembly, wherein:

• said upper bearing assembly includes upper and lower bearing parts that have bearing surfaces that substantially face each other, with the upper bearing part connected to said turret and the lower bearing part connected to said hull;
• a plurality of individual devices that lie between said upper and lower bearing surfaces, with each device having upper and lower elements lying respectively against said upper and lower bearing surfaces, with said upper elements being moveable with respect to said upper bearing surface and said lower elements being moveable with respect to said lower bearing surface, and with said upper and lower elements being biased apart but being largely vertically moveable relative to each other;
• at least one of said bearing parts has concentric inner and outer track walls that form a circular track between them and that confine said devices to relative movement along said track;
• said devices have circular peripheries that lie between said track walls.

An offshore system which includes a vessel hull that floats in a sea and that can weathervane and that forms a vertical opening, a turret that lies in said opening, a mooring structure that extends from said turret to the seafloor, and a bearing structure that rotatably supports said turret on said vessel and that includes an upper bearing assembly, wherein:

• said upper bearing assembly includes upper and lower slider bearing rings that lie facewise adjacent at an interface, with the upper bearing ring connected to said turret and with said lower bearing ring coupled to said hull;
• a source of pressured lubricant coupled to said interface;
• a first of said slider bearing rings has a plurality of fluid seals at said interface that divide said first slider bearing ring into a plurality of segments that are circumferentially space about said axis, and said source of pressured lubricant has a plurality of outlets that each supplies pressured lubricant, with at least one outlet opening to each of said segments;
• a plurality of support structures that are circumferentially spaced about said axis and that each supports a location along said lower slider bearing ring on said hull, each support structure comprising a quantity of elastomeric material with said quantities of elastomeric material supporting the weight of said turret and loads thereon.

An offshore system which includes a vessel hull that floats in a sea and that can weathervane and that forms a vertical opening, a turret that lies in said opening, a mooring structure that extends from said turret on said vessel and that includes an upper bearing assembly, wherein:

• said upper bearing assembly includes upper and lower slider bearing rings that lie facewise adjacent at an interface, with the upper bearing ring connected to said turret and with said lower bearing ring coupled to said hull;
• a source of pressured lubricant coupled to said interface;
• a first of said slider bearing rings has a plurality of fluid seals at said interface that divide said first slider bearing ring into a plurality of segments that are circumferentially spaced about said axis, and said source of pressured lubricant has a plurality of outlets that each supplies pressured lubricant, with at least one outlet opening to each of said segments;
• said interface has radially inner and outer regions, and including inner and outer seals that respectively seal said inner and outer regions of said interface, with said outer seals being constructed to rapidly leak pressured lubricant from an interface outer location that exceeds a predetermined thickness, whereby to oppose tilt of said turret.