Development of a Screening System to Identify Deepwater Wells at Risk for AnnularPressure Build-up

摘要

Annular Pressure Build-up (APB) in wellbore annuli is aproblem in most deepwater wells. If APB induced loadscompromise string integrity, the selection and design of asuitable APB mitigation strategy must be pursued. Thecalculations required for such analyses can be tedious, since anumber of cases to identify key variables and “what-if”scenarios must be evaluated. Though analytical techniquesrequired to evaluate APB and mitigation strategies are wellunderstood, there is a need to perform these calculationsquickly and reliably.This paper discusses the development of a procedure andcomputational tool to determine deepwater wells at risk forAPB. Though the tool structure is simple enough forspreadsheet implementation, it is technically and numericallyrigorous. The role of the tool is illustrated with a case studywhere one or more mitigation strategies are necessary for wellintegrity. Details required to build such a tool, I.e. Assemblethe matrix of APB equations, develop quantitative models ofmitigation strategies, and, most importantly, create amathematical representation of a wellbore for use in the APBalgorithm, are presented in the appendices. Finally, for thefirst time, the role of formation elasticity (I.e. The annularboundary conditions) on APB is examined by using equationsthat treat the formation as an elastic foundation.