Numerical study of helical flow field in horizontal annulus

The annular helical flow field is one of the most significant factors to transport particles in the horizontal wellbore when compared with solids cleanout operations by the transverse jet flow. This chapter investigates the mechanism and characteristics of the annular helical flow by rotary jet using the computational-fluid-dynamics approach. The effects of flow rate, jetter rotation speed, nozzle assembly, flow rate distribution, and fluid type on annular helical flow field are analyzed. The recommended nozzle assembly and its flow rate distribution in the forward, lateral, and backward nozzles are obtained. This study helps design a cleanout tool and in optimizing the hydraulic parameters and operation's procedures.