Dynamic Distribution Characteristics of Oil and Water during Water Flooding in a Fishbone Well with Different Branch Angles.

Abstract

Lab experiments, field pilots, and numerical modeling focusing on fluid flow aspects have indicated that multi-branch wells are technically effective and promising. Several researchers have conducted some experiments for a fishbone well strategy with mixed results. Our objective in this work is to study the impact of the different fishbone well patterns, such as branch angle, on the distribution of remaining oil after water flooding. In this paper, the interference effect between branches on oil recovery is studied in three steps. First, the interferences between fishbone wells with different branch angles were measured by hydro-electric simulation experiments. Second, two-dimensional visualization water flooding experiments were carried out to clarify the remaining oil distribution at different branch angles. Third, the distribution of oil and water in fishbone wells was verified by establishing a numerical model. The modeling results agree well with the experimental phenomena. At the same time, the variation trend of water and oil production in each branch is analyzed by numerical simulation results. The results indicate that the production is strongly dependent on the branch angles, and the highest recovery was 60.2% at a 45° branch angle.