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This study is aimed at the problems of traditional vortex tools in gas wells, including notable pressure losses and short effective distances. An organic combination of jet vortex drainage and gas production tools was designed and installed without additional power equipment. Based on the liquid film force balance model, gas–liquid two‐phase flow and turbulence models of the jet vortex tool were established with UG and Fluent flow simulation software. The gas–liquid mixture was analyzed before and after the jet vortex tool, and the flow trajectory, pressure loss, liquid volume fraction change, and change rate were examined. According to the simulation results, the comprehensive influence of each structural parameter on the effective working distance was optimized, and optimal structural parameters of the jet vortex tool were obtained. The results indicate that the jet vortex tool reduces the critical liquid‐carrying flow rate and pressure loss and increases the axial and initial velocities of the gas and liquid phases, combined with swirl tool distance model, the effective flow distance is increased correspondingly, and the liquid‐carrying capacity of the gas well is improved.

In the process of natural gas purification, common baffle demister has the problem of low separation efficiency and incomplete separation of fine droplets with the particle size in the range of 5-25 μm. This situation not only affects the quality of natural gas, but also causes corrosion and damage to gas equipment, and even seriously affects normal production. In order to solve these problems, we have carried out an innovative design for its structure. Based on the single-stage baffle, vortex blades are added at the first straight plate section from the inlet and the second straight plate section in the middle to enhance the turbulent vortex degree and complexity of the flow field in this area and improve the probability of collision of small particles with the wall, thus achieving the purpose of improving the demisting efficiency. In this paper, performance of the new mist eliminator is analyzed and evaluated by means of experimental study and computational fluid dynamics (CFD) numerical simulation. The results show that when the flow rate is 3.5-5.5 m/s, total separation efficiency of the new mist eliminator for fine particles with a particle size of 5-25 μm is about 51.72%-86.13%, which is about 38.57%-55.76% higher than ordinary baffled mist eliminator. The separation efficiency of particles with a diameter of 5 μm is about 31.79%, increased about 26.15%. The separation efficiency of particles with a diameter of 10 μm is about 52.09%, increased about 37.21%. In addition, when the flow rate is 3.5-5.5 m/s, the pressure drop is increased by about 41.68-135.97 Pa. It could be concluded that the new type of mist eliminator could effectively improve the demisting efficiency of fine droplets.

Wax deposition is an important factor that influences oil production for high-wax crude oilfield. There are few studies on the formation damage by wax deposition, especially cold damage to the shallow low-temperature reservoir. With laboratory tests conducted on reservoir oil and cores of Changchunling Oilfield, this study aims to experimentally investigate the influence of temperature variations on characteristics of oil–water percolation and cold damage mechanisms, as well as the relative permeability of high-wax reservoirs. Experimental results show that seepage flow of high-wax crude is significantly sensitive to temperature-wax deposition evidently increases, whereas the cold damage such as the pore-throat radius and relative permeability sharply decrease with the decline in formation temperature. The research results can be applied to enhance oil recovery of high-viscosity or high-wax oilfields.

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