The Relative Importance of Drawdown and Depletion in Sanding Wells: Predictive Models Compared With Data From the Statfjord Field MM

Abstract

Abstract Experience of sand production from the Statfjord field has been systemized to be able to predict the effect of drawdown and depletion on sand production. The aim of the study is to determine how reservoir pressure depletion will influence the sand production and to determine how sand production will influence the maximum liquid production rates. Most wells produce according to a maximum acceptable sand production criterion. Field data based on more than 300 maximum acceptable sand rate tests have been systemized by fitting those to an empirical criterion. For a better determination of the parameters, sand production histories of four wells have been analyzed in detail. To understand more about the mechanisms underlying the sand production, the field results are compared with four different models. This work concludes that the behaviour of sanding wells at Statfjord can be described by a concept of two sand production regimes, one controlled by shear failure and the other controlled by rate. Finally the empirical model is used to extrapolate the field experience to low reservoir pressures related to the planned deep depressurization. The results show that sand production will limit well production rates unacceptably for most formations and that downhole sand control is needed to secure high production rates during the late-life development of the field.