Abstract: The present disclosure provides a method for experimentally determining a critical sand-carrying gas velocity of a shale gas well. The method includes: collecting well structure and production data, calculating parameter ranges of a gas flow velocity and a liquid flow velocity; carrying out a physical simulation experiment of sand carrying in the shale gas well to obtain the sand holding capacity of the wellbore under different experimental conditions, and calculating a sand holding rate; by observing a change curve of the sand holding rate of the wellbore vs. the gas flow velocity, defining a turning point, and sensitively analyzing the influence of other experimental variables on the turning point, to calculate the critical sand-carrying production of the shale gas well under different conditions. Therefore, this calculation method is simple and applicable, and provides a theoretical basis for the optimization design of water drainage and gas production process.

Abstract: An experimental method for determining flow patterns in vertical wellbore of gas wells at high-pressure conditions, which falls within the technical field of deliquification for gas reservoirs. The method comprises: collecting target block parameters; Developing physical simulation experiment to measure the liquid holdup of vertical wellbore; Constructing similarity dimension number to characterize gas density and change with liquid holdup to represent flow similarity of different gas velocities at different pressures; Utilizing equal liquid holdup to represent flow similarity, fitting similarity dimension coefficient, normalizing flow under different pressure conditions to same similarity dimension number, realizing coincidence of change cure of liquid holdup of normal pressure and medium pressure with similarity dimension number.