Advanced Modeling of Well Tubulars Erosion by Solids Including Multiphase Effects

Abstract

Solids erosion of well tubulars can be a major factor impacting production rate limitations. It is well known that erosion rate is very sensitive to production rate. Thus, large uncertainty in erosion rate predictions can result in conservatism in lifetime erosion predictions. As a result, operators may unnecessarily reduce production rates due to fears of an erosional failure of the well tubulars. The best way to predict erosion is through experimental testing; however, in many cases experimental testing can be unrealistic prompting the use of various erosion predictive models to improve well design and production practices. Erosion is a complex phenomenon and even with the most comprehensive and accurate models based on Computational Fluid Dynamics (CFD) prediction of erosion rate is often only a ballpark estimates without proper validation. Furthermore, many wells produce both gas and liquid resulting in different multiphase flow regimes. The location of each phase in the flow stream can have a significant impact on erosion rates. For example, it is known that the presence of thin liquid films along tubular walls in gas flows can significantly reduce erosion rates. Thus, complex modeling of multiphase flow must be incorporated into erosion models in order to accurate capture erosion rates. This paper presents a comprehensive CFD-based model applicable to various well completion types. Our model incorporates solids erosion as well as various multiphase flow regimes. The model was validated extensively against experimental data and shown to improve on previously published erosion patterns and trends in terms of both erosional hot spot locations and erosional rates. This improved model can significantly reduce the uncertainty in solid erosion prediction for use in the selection, design and optimization of well tubulars and completion equipment (e.g. wire wrap screens and inflow control devices).