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你提的问题的答案基本是肯定，恭喜你 请参考API SPEC 16F <Marine Drilling Riser Equipment>
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Section 13 Buoyancy Equipment
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13.2.2 Design and 13.2.4 Dimensions
13.2.2 Design 13.2.2.1 The purchaser shall specify the net lift per joint to be provided by the equipment. The buoyancy calculation shall be based on the weight in seawater of the riser and all its metal accessories, as shown in the following example: Riser joint weight in air = 11,250 lbs. Riser joint weight in seawater = 0.87 × 11,250 = 9,788 lbs. Desired buoyant lift = 95% (defined by purchaser) Net lift per joint = 0.95 × 9,788 = 9,298 lbs. Note: This is nominal buoyancy; tolerances on buoyancy are defined in 13.2.6.3. The above calculation is based on a standard carbon steel riser and a nominal seawater density of 1.025. Other seawater densities and/or riser material will require alternate calculation formulas. 13.2.2.2 The design and construction of the modules shall take into consideration the requirements of riser handling, storage, and maximum riser deflection (under dynamic conditions) based on parameters of the stacking arrangements provided by the purchaser (i.e., cordwood vs. vertical, battens/no battens, etc.). The material shall be strong enough to permit riser joints with buoyancy to be safely stacked without affecting performance. The manufacturer shall state the maximum height to which joints can be stacked without damage under conditions specified by the purchaser. These conditions shall be documented. 13.2.2.3 The length of the buoyancy equipment shall be such that sufficient clearance is provided for riser couplings and for supporting the riser on the spider during running or pulling operations. The buoyancy equipment shall also provide adequate clearance for choke/kill, and auxiliary lines and couplings. 13.2.2.4 Thrust collars shall be provided for the transfer of longitudinal forces into the riser pipe or connectors. The downward longitudinal force shall be assumed to be at least twice the full dry weight load (to account for impact loads) and the upward force shall be the total net buoyancy force. The syntactic foam modules shall be attached to the riser with material of sufficient strength to hold the modules securely in place. The design shall be such that the attachment means is not exposed to damage in normal handling. Corrosion shall be considered in the design. 13.2.4 Dimensions The internal radius of the modules shall conform to the outer radius of the riser pipe without binding or excessive looseness. The purchaser shall specify any special shape requirements. Flexure lugs or elastomeric spacers may be located on the inner radius of each module to provide clearance and prevent transfer of bending forces between riser and buoyancy equipment. | 
发表于 2009-9-25 09:31
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