Modelling and simulation of particle agglomeration and deposition in turbulent channel and pipe flows

We present a model for the formation, break-up, deposition and re-entrainment of solid particle agglomerates in turbulent flows. The turbulent flow of the liquid carrier is represented through Direct Numerical or Large Eddy Simulations. The structure of the agglomerates, which are formed by inter-linked spherical primary particles, is explicitly taken into account in this model. While firstly still ignoring deposition and re-entrainment, we present results on the properties of the agglomerates formed both in channel flow, and in flow in a cylindrical pipe. The collision rate of the agglomerates is found to be under-predicted by the Saffman & Turner collision kernel by up to a factor of 10. We also present results on the modification of the turbulence due to the presence of the agglomerates. Furthermore, results on the deposition and re-entrainment rate of the agglomerates, as well as on the additional streamwise pressure drop induced by the deposition are presented. Ultimately, the results obtained this way are used to construct improved engineering models for predicting asphaltene deposition during crude oil production.This research was carried out in the context of the Integrated Systems Approach to Petroleum Production (ISAPP) Knowledge Center. ISAPP is a joint project of the Netherlands Organization for Applied Scientific Research (TNO) and Delft University of Technology, sponsored by ENI, Petrobras, and Statoil.