A computation scheme was implemented in a general-purpose, finite-difference simulator to model multi-lateral wells. Frictional pressure drop along the wellbore and proper fluid mixing at lateral connection points were included in the calculation of wellbore pressure profile for each lateral. The formulation is general and a lateral can be branched out from any point along the main well path.
Since the production profile of each lateral is influenced by the wellbore pressure distribution, the prediction accuracy depends on a good wellbore flow model. We implemented the Beggs and Brill1 correlation, a homogeneous flow model, and a new model proposed by Ouyang et al2 which included an acceleration term and accounted for the lubrication effect due to radial influx. We compared well performance prediction results using the three models.
We studied the impacts of different tubing sizes on the well performance and the production contribution from each lateral.