Maximum liquid-carrying capability of airflow in gas well

The critical gas flow is widely used to judge the loading status of vertical gas wells. Though it could demonstrate the carrying ability of gas flow, it cannot quantify how much liquid it can remove and it does not take into account the fact that the liquid-carrying ability of gas flow is limited in theory. In fact, the gas wells still load even if the gas production rate is larger than the critical gas flow, as the gas flow rate is not capable of bringing the whole liquid out of a pipe. In this study, the model of maximum liquid-carrying capability was established on the basis of the pipe flow dynamics theory to quantify the liquid-carrying ability of gas flow. By verifying the model with experiments, the formula of the maximum liquid-carrying capability under different degrees of deviation was obtained. Afterwards, the model was tested with the on-site data of the Sebei gas field. The results show that the relative error of the model is generally less than 10%, which meets the requirement of the gas field development. Finally, the graph of airflow capability was obtained, which brings convenience for the operators to estimate the liquid-carrying ability and make a healthy evaluation for the well.