Production performance prediction is crucial to ensure prolonged, stable and efficient production of gas wells. But for wells that producing water and sand simultaneously, many complicated factors as sanding, water production, wellbore liquid-carrying, wellbore sand-carrying and downhole liquid-loading must be involved in besides normal coordinate curve, which may consists of inflow performance curve, working curve of pipeline and that of choke as well. Water seepage influence on inflow performance, dynamic critical sanding pressure drawdown curve and wellbore liquid-carrying and sand-carrying capacity are provided and discussed intensively in this documentation, based on normal production performance coordinate curve analysis of gas wells.
By analyzing the complicated production conditions provided above, an integrated coordination chart(ICC) is put forward specialized for gas wells that may produce water and sand, which contains all information revealed by normal production performance coordinate curve and any other sophisticated but essential curves or data for wells that producing water and sanding. The application results indicate that the integrated coordination chart is reliable in diagnosing the rationality of operating system and corresponding optimization of gas production rate and pressure, it can also be used to estimate reasonable size of pipeline and downhole choke and provide effective sand-control or water-plugging recommendations.
The integrated coordination chart has been used successfully in SeBei Gas field, China to predict production performance and homologous operating system adjustment for more than 60 wells, which include 15times sand removal operation, 5times sand-control operation and 40times adjustment of operating system. The application result showed a match degree of almost 90%.