Kekeya Deep Gas Condensate Reservoir Downhole Choking Simulation

The underground restriction of condensate gas well is a very important link in the exploitation of condensate gas reservoirs. Throttling on ground need to use calefaction and heat preservation equipment to rise and keep the temperature of natural gas stream lest hydrate form. The characteristic of condensate gas well is that can condensate oil with the drop of preaaure. The ordinary underground restriction of gas well is not dapt to describe actual flow condition, and must consider the existence of liquid. So, we need to research sole gas phase and two phase currents separately. Underground restriction with natural gas is a new research direction in exploitation craft of natural gas. Underground restriction is a craft technique of gas exloitation in order to depress wellhead pressure, control output and cancel ground calefaction at temperature. It is that the nozzle is put on an appropriate location in wellbore in order to depress pressure and avoid hydrated compound at the same time by making use of terrestrial heat which makes more current temperature after throttle than original temperature of hydrated compound formation.On the base of reasonably predigesting relevant physical model, the group of equation of pressure, temperature, flux and density about well was educed by the conversation of mass, momentum and energy and logical mathematical model is set up. To some gas-wells which are given original and boundary condition, we compute the program which is made by the C language so that the distribution of correlative parameters of gas in wellbore are found out with well depth. By the results, we validated the usability of this simulator and its important significance to research underground throttle.Making use of the above mathematical model, numerical value method and homologous calculation procedures, we can get the distribution of correlative parameters of fluid in wellbore, including the distribution at nozzle. But these parameters distribution is one dimensional with well depth. At nozzle where section is very various, laminar flow turn into turbulent flow, velocity change subsonic one into supersonic one, and Shockwave occurs at the same time, the flow state is very complicated. This complicated fluxion must be described with two dimensions or three dimensions. Here, by using CFD software(Fluent), we can simulate the state of fluid at nozzle and obtain the distribution of correlative parameters of fluid and some else characters. Because of the axial symmetric cylinder, we only simulate 2D state.