Abstract: Based on gas transient flow theory and the pressure drop analytical solution of the horizontal gas well obtained by Newman's product principle and Green function, combined with rotation of axes deriving the pressure drop equation of the sidetrack, the transient deliverability prediction model of herringbone gas wells is presented and solved by discretization. Computational analysis shows that: ① The production of herringbone gas well decreases with time, followed by tending to a certain rate, and characterized by pseudo-steady state flow; ②The unit length flow rate of main wellbore trends to great at both ends and small in the middle, with the smallest in the intersection, and the farther from the main wellbore, the greater the unit length flow rate of sidetrack wellbore is.

Key words: herringbone gas well, unstable state productivity, prediction model, forecasting model, flow distribution