Rapid calculation method for water flow rate at gas drilling site based on pressure drop

Water production in the bottom hole is a frequent occurrence during gas drilling, posing a significant threat to the safety of the process. Obtaining the water flow rate quickly is critical to making further engineering decisions. This paper proposes a rapid calculation method of water flow rate based on the principle of pressure drop. The method can quickly identify the multiphase flow pattern and calculate the flow pressure drop, thereby establishing the relationship between the gas injection pressure and the water flow rate. At the gas drilling site, the gas injection pressure is continuously monitored in real-time, which enables rapid acquisition of the real-time water flow rate. The concept of ultimate water-carrying kinetic energy is introduced, which combined with the boundary of annular flow to other flow patterns, can determine the maximum water-carrying flow rate. The feasibility of this method is validated using the field-measured data of well X8-3.