| With petroleum development entering the later stage, the water production emerges in gas wells. In order to solve this problem, the new technologies for the exploitation of low yielding water wells should be exploited. With the mining of low yield wells, the bottom-hole pressure is reduced. When the gas flow rate is below the critical velocity, the loading liquid could not be carried to the ground. The effusion of water that piles up in the wellbore will suppress bottom-hole pressure and make it more difficult to drain water. If we don’t deal with this problem, the gas well may be scrapped.There are a lot of processing technologies to solve the problem, such as velocity string, plunger gas lift, foam drainage, pipe pump, gas lift drainage and electric submersible pump drainage etc. But these processes have limitations for low pressure low yielding wells. The vortex tool can change the flow pattern about the mixture of gas and liquid so that the laminar flow becomes turbulent. It can reduce the critical liquid carrying flow and pressure tubing. The vortex drainage gas technology is one of mechanical dewatering gas technologies. It has such following characteristics as being easy to use, low cost and better applicability for the emergence of this issue. The vortex tool has good prospects in Sulige gas field, southern Sichuan gas field, Daqing field and other areas.Based on the fundamental theory about vortex flow, a three dimensional model and three dimensional model of the flow channel 2-7/8 vortex tools are built in this paper. The formula is derived on the basis of the physical parameters of two phase flow. After considering the actual conditions in Sulige gas field, the vortex flow field simulation tool inlet boundary is deduced. The 16 kinds of vortex tools have different structures. The structures combine with a ribbon angle, an inner diameter of the spiral, and an outer diameter of the spiral. With the digital simulation of the spiral area of flow field, it reveals the distribution of gas liquid mixture and the discharge mechanism. It reaches the conclusion that three factors influence the effect of vortex tools draining. (1) As the helix angle increases, the ability of the drainage increases and later declines. With the increase of the inner diameter of spiral belt, the discharge capacity decreases and then increases. With the increase of outer diameter of the spiral, the discharge capacity increases, and then gradually decreases. At the same time, the stimulation gets conclusion that the helix angle influences the axial velocity of the droplets and adhesion on the wall largely. The inner and outer radii influence the swirling strength of the liquid mixture and the loss of local resistance as well. (2) By orthogonal test method with three factors and four levels, an optimum size of vortex tools is selected. Then, it is verified via the pressure drop. (3) The conversion of parameters in the process of stimulating, that is to say, the conversion of the parameters commonly used into the effective parameters in stimulating, reaches an conclusion, by contrasting holding liquid dispersion rates in importing and exporting under different liquid ratio and different speeds. With the gas liquid ratio increasing, the holding liquid dispersion rate decreases. Smaller the holding liquid dispersion rate, the more the discharged liquid. That is to say, it is easier to achieve drainage. If it is the same diameter, higher the flow rate bottom, better the effect of draining. Thus, in context of high gas liquid ratio and the quick flow of bottom, it is more beneficial to the production of vortex tools. The results of this study may provide some reference value for the application of the vortex tool in drainage gas. |
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