Design and Numerical Simulation Study of a Novel AICD for Water Control and Gas Production in Gas Wells

Abstract

The automatic inflow control device (AICD) used for water control and gas recovery in gas wells as the core component of gas well intelligent layered/segmented production and water control technology is very important for the development of advanced well completion (AWC) technology in water-producing gas reservoirs. Therefore, the design of AICD to ensure that the gas flows smoothly inside it and to keep water under control to a greater extent can maximize the performance of the AICD, and the most important thing is to restrict the water in the formation from entering the wellbore. However, currently, there are very few designs and research on the AICD used for water control and gas production in the gas wells, and the performance of this type of tool and the law of gas and water flow inside it are not perfect, so more in-depth research is needed. In this paper, a new type of AICD is designed to realize the function of water control and gas flow smoothly, and the DoE of the new AICD is carried out, determining the factors that will affect the key technical indicators and the factors that may have interactive effects, using the numerical simulation method of computational fluid dynamics to carry out optimal design, conducting fluid physical property sensitivity analysis, and flow rate applicability analysis. The results show that the tool is not sensitive to the viscosity of water and gas in different gas reservoirs but is very sensitive to the density of water and gas. When the gas/water flow rate ratio is less than 4, it can exert its water control effect. In addition, the results of multiple sets of physical experiments are well consistent with the simulation results; the average deviation of single-phase water is 10.91% and the average deviation of single-phase gas is 11.85%. Computational fluid dynamics and physical experiment results show that, under these conditions, the difference in fluid flow characteristics can be fully exploited; the channel is automatically identified to produce a small gas pressure drop and a large water flow pressure drop. The research in this paper belongs to the key technology of the AWC technology of gas wells in the new water control strategy of the current and has a certain reference value to make up for the defects of drainage gas recovery technology in the water management strategy..