Accurate characterization of the flow characteristics of shale gas horizontal wells is the key basis for quantitative evaluation of production performance and further guidance of development program optimization design. In order to explore the gas-liquid two-phase flow law of shale gas horizontal wells at different inclination angles

a three-dimensional simulation wellbore model with the pipe diameter of 0.124 m

pipe length of 10 m

and inclination angles of 0°

5°

10°

15°

20°

30°

45°

-5°

-10°

-15°

-20°

-30°

-45° respectively is constructed. The volume model is used to track the gas-liquid interface. The characteristics of gas-liquid two-phase flow in wellbore are dynamically monitored. The flow pattern

velocity and holdup distribution characteristics of wellbore with 300 m

3

/d liquid volume and 500 m

3

/d gas volume are obtained by simulation experiments under various well inclination angles

and the influence law of well inclination angle on gas-liquid two-phase flow characteristics of shale gas horizontal wells is deeply analyzed. The results show that the flow pattern of up-dip pipe（well angle is larger than 0°） is characterized by slug flow

and the average fluid velocity changes in a single-peak form with the increase of well angle

and the peak appears when the well angle is 15°. The flow velocity at the gas-liquid interface is the lowest

and the bottom water holdup is larger with lower well angle is than that with higher well angle

and reaches the maximum value when the well angle is 10°. The flow pattern of down-dip pipe（well angle is less than 0°） is characterized by stratified flow

and the average fluid velocity is linearly increasing with well inclination angle. The flow velocity at gas-liquid interface is between the top and bottom value

and the bottom water holdup decreases with the increase of well inclination angle.