Abstract
The features of gas wells’ water-cut in multilayer fields have been characterized and the expediency of watercut wells’ operation with the joint extraction of gas and water has been substantiated. The gas-lift method of watercut wells’ operation has been considered. Using the calculation method proposed by the authors, the study of the impact on the rate of gas flow coming from the reservoir and the water factor downhole pressure, the depth of the gas lift valve on the tubing and gas-lift gas consumption has been conducted. The research has been carried out under the conditions of a model water-cut gas well at constant values of the wellhead pressure and the diameter of the tubing. The regularities of changes in the production gas rate and bottom-hole pressure with an increase in the gas-lift gas flow rate, which are the same for all the investigated values of the water factor, have been established. The bottom-hole pressure first decreases and reaches a minimum, after which it increases. The formation gas production rate first increases and after reaching the maximum decreases. With an increase in the water factor, the bottom-hole pressure increases and the formation gas flow rate decreases, and those values will grow more, the lower the depth the gas-lift valve is located. With an increase in the depth of the gas-lift valve, the bottom-hole pressure decreases and the production rate of formation gas increases, and they will be more intense, the greater the water factor. Based on the results of statistical processing of the calculated data, the rational depth of the gas-lift valve on the tubing has been established for various values of the water factor, above which the formation gas flow rate and bottom-hole pressure change little. With an increase in the water factor, the rational depth of the gas-lift valve placement on the tubing will increase