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Dealing with Annular Pressure Build Up

Decent Essays
Annular pressure build up (APB) is an important problem in the areas of well design. Although different suggestions have been proposed to mitigate APB, including vacuum insulated tubing, silicate foam wellbore insulation techniques, and insulating completion (packer) fluids, consistent, robust APB mitigation solutions that include the optimized annular fluid rheology of the trapped drilling fluids in the outer annuli are needed to better handle this problem.
The convective and conductive heat transfer through the trapped drilling fluid between the casing strings is a driving force for increasing the annular pressure. This study explains how to design and optimize the rheological and thermal properties of drilling fluid to provide a sustainable and reliable insulating performance. The objectives of this study are 1) to develop a better insight of APB in the annulus of casing and 2) to experimentally measure and 3) analytically model the effect of different parameters, such as rheological and thermal properties, on the insulating performance of drilling fluid trapped in annular spaces. By combining the theory of sedimentation and the model proposed for free convective heat transfer of Yield Power Law fluids across parallel plates, a stepwise guideline was proposed to estimate the Nusselt number and thermal conductivity coefficient profile of trapped drilling fluid. A computer code to perform this procedure has been developed. Additionally, a unique experimental apparatus was
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