Modeling High-Viscosity Oil/Water Cocurrent Flows in Horizontal and Vertical Pipes

摘要

Water is produced along with heavy oil either during the primary production or during enhanced oil recovery. Therefore, cocurrent oil/water flow is a common occurrence in heavy-oil production and transportation. Production-system design is strongly dependent on accurate predictions of the oil-/water-flow behavior. The predictions of previous mechanistic models for pressure gradient and water holdup are tested with the data acquired, and significant discrepancies are identified, especially for horizontal flow (Vuong 2009). The model performance is largely dependent on the predictions of phase inversion, distribution, and interaction. On the basis of the new understandings from experimental observations, the Zhang and Sarica (2006) unified model is modified by adding a new closure relationship for water-wetted-wall fraction in stratified flow and a new interfacial shear model based on mixing-length theory. The new model is compared with both high-viscosity and low-viscosity oil-/water-flow experimental results, and significant improvements are observed.