A New Model to Predict Average Pressure Difference of Liquid Droplet and Its Application in Gas Well

Haiquan Zhong, Jiao Tan, Chi Zhang

School of Petroleum Engineering, Southwest Petroleum University, Chengdu, China.
The State Key Lab of Oil/Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, China.

DOI: 10.4236/eng.2014.68042                

Abstract

The distribution of droplet surface pressure is uneven under the action of high velocity gas streams in gas wells, and there exists a pressure difference which leads to droplet deformation before and after the droplet. Moreover, it affects the critical liquid carrying rate. The pressure difference prediction model must be determined, because of the existing one lacking theoretical basis. Based on the droplet surface pressure distribution in high velocity gas streams, a new model is established to predict the average differential pressure of droplets. Compared with the new differential pressure prediction results, the existing pressure difference prediction results were overvalued by 46.0%. This article also improves four gas-well critical liquid carrying models using the proposed pressure difference prediction model, and compares with the original one. The result indicates that the critical velocity of the original models is undervalued by 10% or so, due to the overestimate to the pressuredifference. In addition, comparisons of the improved model with original models show that it is necessary to consider the adaptability, because the models have significant differences in results, and different suitability for different well conditions.

Keywords

Gas Well, Continuous Removal of Liquids, Liquid Droplet, Average Pressure Difference, Deformation, Model Comparison

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Turner, R.G., Hubbard, M.G. and Dukler, A.E. (1969) Analysis and Prediction of Minimum Flow Rate for the Continuous Removeal of Liquids from Gas Wells. JPT, 11, 75-82.
[2]	Li, M., Guo, P. and Tan, G.T. (2001) New Look on Removing Liquids from Gas Wells. Petroleum Exploration and Development, 5, 105-106.
[3]	Li, M., Li, S.L. and Sun, L.T. (2002) New View on Continuous-Removal Liquids from Gas Wells. SPE Production & Facilities, 1, 42-46.
[4]	Wang, Y.Z. and Liu, Q.W. (2007) A New Method to Calculate the Minimum Critical Liquids Carrying Flow Rate for Gas Wells. Petroleum Geology & Oilfield Development in Daqing, 6, 82-85.
[5]	Wei, N., Li, Y.C., Li, Y.Q., et al. (2007) Visual Experimental Research on Gas Well Liquid Loading. Drilling & Production Technology, 3, 43-45.
[6]	Peng, C.Y. (2010) Study on Critical Liquid-Carrying Flow Rate for Gas Well. Xinjiang Petroleum Geology, 1, 72-74.
[7]	Wang, Y.W., Zhang, S.C., Yan, J., et al. (2010) A New Calculation Method for Gas-Well Liquid Loading Capacity. Journal of Hydrodynamics, 6, 823-828. http://dx.doi.org/10.1016/S1001-6058(09)60122-0
[8]	Dai, G.C. and Chen, M.H. (1988) Chemical Fluid Mechanics. Chemical Industry Press, Beijing, 68-90.
[9]	Guo, L.J. (2002) Two Phase and Multiphase Flow Mechanics. Xi’an Jiaotong University Press, Xi’an, 502-510.
[10]	Flachsbart, B. (1965) Liquid-Gas Interfaces Studied on the Basis of the Classical Surface Tension Theory and Intermolecular Force Models. Stanford University, California, 102-108.
[11]	Loth, E. (2010) Particles, Drops and Bubbles: Fluid Dynamics and Numerical Methods. Cambridge University Press, London, 149-150.
[12]	Hinze, J.O. (1948) Critical Speeds and Sizes of Liquid Globules. Applied Scientific Research, A1, 273-287.
[13]	Lin, Z.H. (2000) A Science of Irregular Change Flow—Multiphase Fluid Mechanics. Tsinghua University Press, Beijing, 44-47.