Deepwater Completion Challenges Redefine Best Practices for Completion andPacker Fluid Selection

摘要

New materials used in deepwater production tubulars, and thernincreasingly complex and costly deepwater projects, demandrngreater attention to the design and selection of completion andrnpacker fluids. This requires an integrated approach, from mudrndisplacement through final sand control completion, in orderrnto optimize fluid compatibility and effectiveness. In additionrnto standard compatibilities with reservoir rock and fluid,rncompatibilities of completion or packer fluid with control line,rnstimulation, and production fluids must be considered.rnFurthermore, compatibility of completion and packer fluidsrnwith production tubular metallurgies must be assured in orderrnto prevent environmental cracking. The impact of thernproduction environment on the potential formation of gasrnhydrates or crystallization of brine due to pressure, at the nearfreezingrnmudline temperatures, must be understood for each ofrnthe wellbore fluids used during the completion process. Forrnsome projects, more than one completion or packer fluidrnchoice is available, in which case each fluid should bernevaluated to select the best ‘fit-for-purpose’ fluid.rnThis paper presents a new paradigm for testing and evaluatingrncompletion and packer fluids for selection in deepwaterrnapplications. Details for each test procedure and evaluationrnmethod are presented and include completion or packer fluidrncompatibilities with formation or synthetic formation water,rncontrol line fluids, and produced fluids. Core flow studiesrnused to test fluid compatibility with the formation rock, andrnstandard stress-cracking tests, conducted according to NACErnguidelines, used to avoid the potential for environmentallyrnassisted cracking of chrome production tubulars, arernpresented. Specialized evaluation methods to avoid thernformation of gas hydrates and the pressure crystallization ofcompletion and packer fluids are also presented. The best fitfor-rnpurpose fluid was selected by following this new paradigmrnfor a GOM deepwater project. Lessons learned arernsummarized in the paper.