Processes
Composites Air Cans Lighten Riser Loads
Low-pressure air cans, designed to add buoyancy to a spar platform’s riser string, are good candidates for composite materials. Up to 12 ft/3.7m in diameter and from 30 to 60 ft/9.2 to 18.5m long, the hollow structures support the riser weight and take load off of the platform’s hull. Typically installed insid
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All-Composite Platforms?
Gibson describes how a team representing the Centre for Composite Materials Engineering, MSP (formerly Maunsell Structural Plastics, Beckenham, Kent, U.K.) and Odebrecht Oil and Gas, a Brazilian-owned platform fabrication company, were tasked with redesigning the topside of BP’s small, minimum-facility Davy-Be
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Design Issues With Tendons
A composite tendon is essentially a rope made from small-diameter rods, which are pultruded with carbon fiber. Multiple rods are gathered together and twisted slightly to form a strand, using typical wire rope stranding methods. Depending on the performance requirements, 10 to 40 strands, about 2 to 3 inches/5
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Design Issues
Typical FRP pipe is reciprocally filament wound with a fiber angle of ±54.75° relative to the longitudinal (0°) axis. This architecture satisfies stress loads in both the circumferential (hoop) and longitudinal (axial) directions for most pipes and pressure vessels. It withstands the in-use pressure, ther
Read MoreSome Design Issues
A variety of resins can be used for offshore applications, depending on the requirements for the final product. General-purpose polyester offers a low-cost option that provides greater corrosion resistance than steel. Isophthalic polyester provides somewhat better corrosion resistance, while vinyl ester is pre
Read MorePetrobras Pioneers Topside Composites
Petrobras (Rio de Janeiro, Brazil) was the first major oil company to experiment with molded gratings in the 1980s, though these early products proved unsatisfactory due to wide variations in mechanical properties. However, advances in pultrusion and filament winding technology coupled with the availability of
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Composite Tether Goes To Sea
Conoco and KOP have manufactured a prototype of a carbon fiber composite tether that could extend TLP production to depths exceeding 10,000 ft/3,000 m. The design has undergone extensive static testing and fatigue loading and has been verified through hydrodynamic model testing. Sea testing is being planned.
Read MoreIssues With Design
Though steel is the traditional material for coiled tubing because of its low price, it is susceptible to corrosion, fatigue failure (caused by repeated coiling and uncoiling), and troublesome joints. In larger sizes, its weight can increase transport difficulties. With the advent of secondary recovery methods
Read MoreSubsea Wellhead And Pipeline Protection Covers
Wellhead and pipeline protection covers are required under the Norsok regulations for subsea installations in the Norwegian sector (Standard U-002, Subsea Structures and Piping System). Traditional steel wellhead covers are very large — often more than 50 ft/15m square — to allow ROVs access to the Christmas t
Read MoreComposite Accumulator Bottles Perform In Service
A riser tensioning system for a TLP consists of a tensioning ring and framework, with four to eight hydraulic cylinders — each with an attached pressure vessel or “accumulator bottle” — to support and allow movement of the rigid riser pipe. Installed in the riser wellbay, this primary structural system is desi
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