Oil-in-water Flow Characteristics Based On The Lattice Boltzmann Simulation Method

Oil-water two-phase flow widely exists in the process of oil production. Theinvestigation on oil-water two-phase flow is of great significance for optimizing oilproducing management. Because of long term water flooding and low oil producing,the low-flow and high water-cut vertical upward oil-water two-phase flow becomesmain part of oil producing process. In particular, the study on oil-in-water bubble flowallows uncovering the local flow structure and flow behavior underlying differentflow patterns.Based on the Lattice Boltzmann Method (LBM), this dissertation investigatesand simulates the local characteristics of oil-water two-phase flow as well as thestructure of bubble-group in oil-in-water bubble flow. The simulation results wellagree with the experimental observation. LBM explains the generation ofbubble-group (from single bubble to multi-bubble group) and the evolutionmechanism of the bubble-group complex motion.The innovative points of this paper are as follows:1. This dissertation simulates the local flow characteristics of single bubble anddouble bubbles. The results indicate that the single bubble presents ellipsoid sharpwhen rising up in water. For double bubble, there exist two situations, e.g.,side-by-side double bubbles and non-side-by-side double bubbles. The conclusions ofsimulation of these two situations are as follows:For side-by-side double bubbles situation, small oil bubble chases and crasheslarge oil bubble, then large oil bubble presents the form of squeezing deformation anddouble oil bubbles bounce off each other. The phenomena of small oil bubble chasingand crashing large oil bubble matches the experiment conclusions of the influence ofthe velocity of oil bubble rising in water subject to oil bubble diameter;For non-side-by-side double bubbles situation, double bubbles show the behaviorof attracting each other and complex random motion resulting from the factor ofbubble attraction principle and turbulence effect.2. This dissertation also simulates the local flow characteristics of oilbubble-group. Similar to double oil bubbles, bubble-group flow also shows thebehavior of oil bubbles attracting each other and complex random motion which leadsto bubble-group presents complex interaction and motion trail. Comparing with the experiment snap-shoot, the results suggest that the LBM is an effect tool for thesimulation and analysis of oil-water two-phase flow.