Abstract:
Riser management systems, apparatus, and methods to maintain a selected range of tension on a plurality of risers extending between subsea well equipment and a floating vessel, are provided. A riser management system can include a mono-buoyancy can platform operably coupled to a plurality of risers extending between subsea well equipment and a moored floating vessel, and a plurality of tensioner units each connected to a top portion of a separate one of the risers to provide tension to each of the risers. The mono-buoyancy can platform can provide tension to each of the risers sufficient to compensate for a relative vertical offset between the risers and the vessel due to vessel movement, which generally affects each of the risers equally, within tolerances, while the tensioner units can simultaneously provide tension to compensate for one or more additional factors which can affect each riser differently.
Abstract:
A method of reducing stress and wear on one or more components in a keel joint assembly in which a cobalt-based, wear resistant alloy coating is applied to the surfaces of one or more components. The use of the coating reduces stress and wear and achieves improved corrosion, galling, erosion and abrasion resistance as compared to other currently known and applied methods. In the present invention, the coating would preferably would be applied to the surfaces of the mating components of the keel joint.
Abstract:
A high pressure spinning nozzle for cleaning material from a surface such as the inner walls of a heat exchanger tube, for example, includes a tubular body having an open front end and a plug in its rear end, a rotor in the body bore having an internal flow passage and inclined and skewed orifices in its front wall that cause the rotor to spin during operation, axial and radial passages in the body to feed high pressure water to the rotor flow passage, a water bearing between the rear of the rotor and the plug, and ports in the body to automatically regulate the pressure of the water bearing.
Abstract:
A riser tensioner cylinder rod incorporates a thin, corrosion-resistant alloy tube over a pre-machined steel alloy rod. The tube is swedged at one end and expanded to the inner surface of a split die. A gradual tapered surface on a stretching die provides a smooth transition during a stretching process for the tube. A pressurizing vessel traps an outer lip of the pre-swedged tube. Pressurized fluid in the vessel simultaneously causes the tube to expand and force the rod into the tube inner diameter. At the completion of the process, the pressurizing vessel is removed. The stretched tube is parted off at both ends and the stretching die is removed from the rod to complete the assembly.
Abstract:
A process for providing a protective layer to an article. The process includes depositing a layer of material onto a surface of the article with a thermal spray process. Examples of thermal spray process include high velocity oxygen/air fuel, atmospheric plasma spray, and chemical vapor deposition. Coating methods, such as cold vapor deposition and physical vapor deposition, may also be used. The layer can then be bonded to the article by heating material in the layer adjacent its connection with the article. Bonding the layer to the article can be performed by irradiating the layer with a collimated light source, the layer irradiation can be applied concurrently with the thermal spray process
Abstract:
A tensioner for an offshore structure has inner and outer barrels engaging each other for movement between retracted and extended positions. The barrels are filled with gas pressure. A primary seal is located between the inner and outer barrels at the open end of the inner barrel. An annular lubricant reservoir is mounted to an interior wall surface of the inner barrel at the open end of the inner barrel. A lubricant port extends from the lubricant reservoir through the inner barrel to a high pressure side of the primary seal for dispensing lubricant between the inner and outer barrels. A fill tube leads from the reservoir to the exterior of the inner barrel for replenishing lubricant.
Abstract:
A corrosion-resistant alloy tube is formed and bonded to a pre-machined steel alloy rod to form a riser tensioner cylinder rod. During assembly, an epoxy is injected into an annular space between the tube and rod and then cured. The bonded tube is ground to a desired surface finish prior to installation and utilizes a double seal arrangement that prevents external pressure or corrosive fluids from entering the cured epoxy in the annular space.
Abstract:
A subsea wellhead assembly allows communication between a production tubing annulus and a conduit in fluid communication with a platform above. The wellhead assembly has a tubing hanger that is held relative to a tubular wellhead member of a subsea well by a tubing hanger support. A string of tubing extends from the tubing hanger into the well, defining an annulus around the tubing. The conduit communicates with the tubing annulus through a tubing annulus passage. The tubing annulus passage has a portion extending through the tubing hanger support. The wellhead member supports a valve block located between the tubing hanger support and the riser. The tubing annulus passage has another portion that registers with the portion of the passage in the tubing hanger support. The conduit stabs into valve block portion of the tubing annulus passage when the riser connects to the upper end of the valve block.
Abstract:
A rotary water blast nozzle assembly includes an inner body member and a mandrel that supports a spray head having an internal bushing that rotates on the mandrel. Seals on the of the bushing are spaced at selected distance points from radial flow ports in its center. The resultant of operating pressure forces acting inward on the outside of the bushing between the seals, and gradually diminishing pressures acting outwardly in the clearance from the center toward the ends of the bushing, together with frusto-conically shaped sections of the bushing, cause uniform inward deflection that reduces the clearance in proportion to the operating pressure to inhibit leakby.
Abstract:
A pipe is wrapped with a composite to form a pre-stressed interface to facilitate load sharing between the materials. Prior to being wrapped, the pipe is placed in tension via hydraulic devices or the like. Alternatively, a combination of cured and uncured composite wraps is used in proximity to each other to apply compressive stress to the pipe. In addition, the pipe may be subjected to cold temperatures to change its dimensions prior to being wrapped with a composite material.