Horizontal Gas Well Gas-water Two-phase The Wellbore Flow Pressure Drop

In recent years, horizontal well technology has been developed greatly in the gas reservoir development. The seepage rule of horizontal well is more and more regarded by scholars while it is extensively applied in the gas field development. Usually, in the middle period and later stage, the horizontal well will product water when it was applied to develop water-content gas reservoir. The flow rule of two phase flow of gas-water has a great difference between single phase of gas in the gas reservoir and horizontal well. Therefore, it has significant sense for preventing liquid loading and determining appropriate working system to research the rule of pressure drop of two phase flow in horizontal well.There are many foreign and domestic scholars who have researched the mechanics of seepage of gas-water and gained rich achievements. But, there are few study on the analysis of production and pressure distribution rule of horizontal gas-water well. This paper developed the research on the following aspects:(1) On the base of production analysis of single phase in horizontal gas well, it proposed composite model for analyzing production of gas-water horizontal gas well, and analyzed its influential factors.(2) It summarized the flow pattern division and transformation of two phase flow in the horizontal pipeline on the base of predecessors'research. It proposed the method of classifying two phase flow pattern and built pressure drop calculating model of slugging and stratified flow in horizontal gas well which consider the effect of radial influx according to the characteristic of horizontal well flow.(3) It built horizontal gas-water well pressure drop calculation model which consider the hole wall friction, acceleration pressure drop and radial influx influence. And it analyzed the main factors which influence the hole pressure drop.(4) It built liquid drop carriage model in horizontal gas well, analyzed the influence of water in the production of horizontal gas well by example. It simulated the gas-water flow in the hole by fluent software.(5) It built coupling model for gas reservoir and gas-water hole according to pressure succession and quality maintenance, discretized the coupling model by node partition theory and computed the model numerically. Finally, it gained the pressure distribution and radial influx distribution of horizontal gas-water well.