This paper was selected for presentation by the OTC Program Committee following review of information contained in an sbstract submitted by the author(s). Contsnts of the peper, as presented, have not been reviewed by the Offshore Technology Conference and sre subject to correction by the author(e). The material, ss presented, does not necessarily reflest anv oosition of the Offshore Technolorw Conference or its officers. Permissionto COPY Is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The ahstra-. ..-. ah6ild oentaln omwplcuous soknowl;dgment of whare and by whom the psper IS"presentad. ABSTRACTA unique process was developed to manufacture a titanium riser stress joint. The weld free 30 foot long TF64(ELI) component was produced so that the flanges were integrally extruded on the tube portion of the riser. The full size production part was extruded following a development program which included subscale trials and finite element modeling to determine metal flow. The amount of titanium required was minimized by the use of a bimetallic preform whereby part of the titanium was replaced by an insert made of a lower cost metal. The component was successfully manufactured to meet all of the customer's requirements. Elimination of weld qualification procedures and minimizing the amount of titanium made the cost of this approach competitive with the method of welding flanges or other available methods. References, tables and figures at end of paper.

During a routine subsea inspection of the Akpo subsea assets, leaks were identified on two of the flexible joints at the top of the water injection steel catenary risers. These leaks were categorised as the highest integrity threats for the district and a task force was formed in order to determine the cause of the leaks and thereby, the most appropriate means to resolve the issue. A phased array UT inspection method has been specially developed to perform underwater inspection of the gasket groove. The nature of the leak was deemed time-critical. The leak was of relatively high volume (the leak rate was estimated at 5 000 cubic meters per day), was worsening and was inducing structural damages to the flexible joint by cavitation. A technical solution was studied involving underwater machining using divers. The upper joint surface of the gasket groove was part of a replaceable spool but the lower joint surface was integral to the flexible joint and therefore had to be repaired in-place. After several months of planning and testing, it was determined that the machining tool was not suitable for the operation by divers. With only a few months remaining in the 6-month target delivery, a second solution was proposed using a composite epoxy mastic repair together with a hybrid steel-elastomer gasket. The use of such a solution would be a first-of-its-kind for this application and would involve underwater grit blasting to achieve proper adhesion of the mastic. It would also involve precise bolt torquing and tensioning in very restricted work space around the flexible joint receptacle and ultrasonic acoustic bolt length measurements, in order to measure the stress in the bolts.