fax 01-214-952-9435. AbstractApplications of a new slag cement and spacer system have reduced the chance of gas channels forming in the cement column during cement hydration in deep, hot south Texas gas wells. These slag cements were formulated with water and conventional cement additives to prevent gas migration and to improve interfacial bonding to oil-wet surfaces. Oil-mud removal spacer fluids (OMRS) were also specially fOlmulated to remove oily residues and improve water-wetting of the oil-wet surfaces. These OMRS can also be designed to develop compressive strength when cementing operations have been completed.Set slag cement provides a tight gas seal with shear-bond healing capacity, as demonstrated by recently developed HTHP shear-bond strength tests. The previously reported phenomenon of healing or regeneration of slag-mix bonds has been reproduced with slag cement. The rapid development of strength at the top of the long cement column and the improved bonding to oil-wet surfaces were the two major improvements provided by the slag cement. OMRS can clean oil-wet surfaces, and then set once the job has been completed.Laboratory tests and field evaluations based on cement bond logs and pressure tests indicated improved bonding and isolation of the gas zones. Field applications of slag cements and OMRS fluids have led to greater primary and plug cementing successes in south Texas gas wells, and well production economics have improved accordingly.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractAfter successfully using an all steel Pre-Installed Mooring System (PIMS) to double Transocean Marianas' mooring capability in the 1990s, Shell improved the PIM system's performance by using polyester ropes in the system. The upgraded mooring system allowed Transocean DW Nautilus to successfully drill several wells in water depth greater than 9000 ft. This paper summarizes the key learning based on the Shell's experience in the Pre-installed Mooring System since 1997, and on the performance results of the Second Generation PIMS using polyester ropes since 2001. The findings based on the experience and test results of mooring hardware after Hurricane Lili in 2002 and Hurricane Ivan in 2004 provide a solid basis for us to improve our design, handling and installation of future polyester mooring systems for both mobile and permanent floating platforms.