Analysis of drilling fluid flow in the annulus of drill string through computational fluid dynamics

Abstract

During an oil and gas well drilling the drilling fluids are pumped through the drill string to cool and lubricate the drill bit. This also serves the purpose of bringing the rock cutting back to surface and serves various other purposes also like pressure control and maintain well bore stability. As the well is drilled the casing are lowed from the well from caving in. This results in a situation where there is an annular flow of drilling fluid where the inner pipe is rotating while the outer pipe is stationary. The understanding of fluid dynamics of such situation is extremely important and detailed investigations are required. Though experimental investigation will reflect the actual behavior but with the advancement is the numerical techniques such experimentation can be avoided with the application of computational fluid dynamics. Therefore, the present study employs the homogeneous model to simulate a single-phase fluid flow and predict pressure loss variation in eccentric vertical annuli as a function of varying drilling parameters: fluid velocity, inner pipe rotation speed