Experiment of Continuous Liquid Lifting Under High Gas–Liquid Ratio Pipe Flow in Gas Well
The feasible allocation of the gas well with high gas–liquid ratio (GLR) depends on the liquid lifting ability of well and reservoir condition. Nowadays, the liquid carrying droplet physical model for gas well is represented by sphere and ellipsoid. Since the two models are different from the stress in the gas flow, the critical conditions calculated by the continuous liquid carrying mathematic model derived from those physical models are different in 2.46 times. The two options have been a focus in petroleum industry for a long time. Therefore, it is necessary to study the physical model of droplet and establish new liquid carrying model. Based on the independently R&D visual experimental rack having the lucite tube with the height of 16 m and diameter of 40 mm, taking the compressed air and water as the experimental media (GLR > 2000), we simulated the continuous liquid carrying under different gas well conditions, such as different pressure and gas rate, capturing the actual shape of the droplet, whose shape is nearly the ellipsoid, in the jet stream by high-speed video camera, testing the wellhead pressure, temperature, gas production, and so on. From the experimental results, it is found that compared with the experimental results, the result calculated by Turner sphere model has 10% error, and the result calculated by ellipsoid model has 58.3% error. The drag coefficient is obtained by analyzing the strained condition of ellipsoid droplet and fitting the experimental data, and the new ellipsoid liquid carrying mathematical model coincided with experiment is derived. Seven wells with water production data have been selected in Chuan-xi gas field, and the calculated results were coincided with the field production according to the new derived ellipsoid model. The experimental research is of significance both to scientific teaching and guiding the field application.
KeywordsHigh gas–liquid ratio Liquid lifting Droplet Experimental study
Minimum flow velocity for liquid lifting, m/s
Critical gas production rate, m3/d
Density of liquid, kg/m3
Density of natural gas, kg/m3
Drag coefficient, dimensionless
Gas–liquid interfacial tension(IFT), N/m
Deviation coefficient of gas under the condition of pressure P and temperature T
Cross-section area of tube, m2
This study was carried out with the support of the National Key Research and Development Program (No. 2016YFC0304008), the Open Fund of the State Key Laboratory of Oil and Gas Reservoir Geology and Exploration, SWPU (No. PLN1309 and No. PLN1418), and the National Natural Science Funds of China (No. 51334003).