A model solution for herringbone well under open hole completion system

A steady state coupling model combining seepage flow and pipe flow was established for herringbone horizontal well, which will provide fundamental theory reference for completion design of complex structure wells. This model focused on open hole completion system and was solved by infinitesimal section method. Each part of pressure drop in coupling flow with existence of completion screen pipes was discussed in detail, and then the flowing pressure and flow rate distribution profiles were given. The analysis results show that, formation sand stack layers in annular space between screen pipes and wellbore produce an additional pressure drop, which make a negative influence on the seepage flow. The flowing pressure and flow rate distribution profiles of wells with screen pipe are lower than those of open hole under the same flowing pressure, and the affection degree primarily depends on sieve size of screen pipe as well as formation sand grain distribution, and partly controlled by local seepage interference. The size of screen pipe, parameters of eyeholes in base pipe and mass transfer in pipe wall have an effect on well bore flow, which makes wellbore flowing pressure distribution profile of overall production section is steeper than that of open hole under the same proration production. By comparing the calculated results with the classical model solutions, the model proposed in this paper is proved reasonable.