Downhole Throttling Device Design And Simulation Used By Shale Gas Development

In the development process of the shale gas, it has often easily generated the phenomenon of hydrate blocking. And this would cause a great damage for the shale gas production. In order to solve this problem, it often used two ways to solve it in the field. One is to use the heat insulation device at well head part, through the heating of shale gas, it can improve the wellhead temperature, so as to make the temperature of shale gas can appropriate placement of the wellbore. For shale gas throttling, it makes the shale gas cooling step-down within the wellbore, and then re-use geothermal for heating the shale gas. After making throttle, shale gas temperature can be higher than the hydrate formation temperature in the wellhead, also it can make the wellhead pressure drop, so as to achieve control of shale gas production, protect the bottom, and reduce the mining cost.In this paper, through analysis of downhole throttling mechanism, energy equation and van der waals rules, we can deduced the theory model of downhole throttling cooling. At the same time, with the mass conservation, momentum conservation and energy conservation as the foundation, by the radial heat transfer model of wellbore flow in the wellbore, the model of the distribution of temperature and pressure is established. Also, by using the application of node analysis method, the fourth order rungekutta method can be used to solve the temperature, pressure distribution along the well depth in one-dimension. This model can be coupled with downhole throttling model of shale gas. So we can set up model with prediction of the parameters of the fluid in the wellbore in one-dimension when using a downhole throttling device. And we can deduce the math model of mouth model of throttling device.Using the established model and corresponding solution mentioned above, all parameters distribution of shale gas can be get. These parameters are related to parameters of well depth of one-dimensional distribution. At the cross section flow nipple, fluid is relatively complex, the changes of a steady laminar to turbulent flow makes the evaluation becomes hard. Therefore, for studying the change of situation, we use the Fluent software to flow through the throttling device of a two-dimensional simulation. In order to flow through the throttle mouth, the parameters of shale gas such as temperature, pressure, the density and the speed can be get in a quantitative description.