A New Model for Predicting Gas-Well Liquid Loading
- Desheng Zhou (Xian Petroleum University) | Hong Yuan (IHS)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- May 2010
- Document Type
- Journal Paper
- 172 - 181
- 2010. Society of Petroleum Engineers
- 5.2.1 Phase Behavior and PVT Measurements, 5.3.2 Multiphase Flow, 3.1.8 Gas Well Deliquification, 4.1.2 Separation and Treating, 5.1.8 Seismic Modelling, 2.2.2 Perforating, 4.1.5 Processing Equipment
- Production and operations
- 9 in the last 30 days
- 2,160 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 12.00|
|SPE Non-Member Price:||USD 35.00|
Liquid loading is a common issue for gas producers. Better predictions of liquid loading will help operators in reducing costs (fewer shutdowns) and improving revenue (greater production).
The Turner et al. (1969) entrained-droplet model--herein referred to as Turner's model--is the most popular one in predicting liquid loading in gas wells. However, there were still quite a few wells that could not be covered even after a 20% upward adjustment (Turner et al. 1969). Field practice also proves that the adjusted model still underestimates liquid loading sometimes. By studying the droplet model and liquid-film mechanisms, this paper presents a new empirical model.
Previous models for liquid loading are independent of the liquid amount in a gas stream. When gas velocity is higher than calculated critical velocity, no liquid loading exists. This paper points out that, in addition to gas velocity, liquid amount (liquid holdup) in a gas stream is also a major factor for liquid loading. There is a threshold value for liquid amount in a gas/liquid mixture. Above this value, liquid loading may appear even when the gas velocity of a well is higher than the critical velocity from Turner's droplet model. The presented model is the first model to include the amount of liquids in the calculation of gas critical velocity. According to the new model, critical gas velocity is not a single value; it varies with the liquid holdup in the gas well once the holdup exceeds the threshold value.
Well data from Turner et al. (1969) were employed in the paper for evaluating the new model's parameters. Data from Coleman et al. (1991) were also used for the validation of the new model. The prediction results from the new model are better than those from Turner's model and are even better than Turner's adjusted model in matching the Turner et al. (1969). The new model is consistent with the Coleman et al. (1991) data and conclusion.
The new model is simple and can be used easily to predict liquid loading in gas wells.
|File Size||618 KB||Number of Pages||10|
Ansari, A.M., Sylvester, N.D., Sarica, C., Shoham, O., and Brill, J.P. 1994.A Comprehensive Mechanistic Modelfor Upward Two-Phase Flow in Wellbores. SPE Prod & Fac 9 (2): 143-152; Trans., AIME, 297. SPE-20630-PA.doi: 10.2118/20630-PA.
Barnea, D. 1987. Aunified model for predicting flow-pattern transitions for the whole range ofpipe inclinations. International Journal of Multiphase Flow 13 (1): 1-12. doi:10.1016/0301-9322(87)90002-4.
Coleman, S.B., Clay, H.B., McCurdy, D.G., and Norris, L.H. III. 1991. A New Look at Predicting Gas-WellLoad-Up. J Pet Technol 43 (3): 329-333; Trans.,AIME, 291. SPE-20280-PA. doi: 10.2118/20280-PA.
Kumar, N. 2005. Improvementsfor Flow Correlations for Gas Wells Experiencing Liquid Loading. Paper SPE92049 presented at the SPE Western Regional Meeting, Irvine, California, USA,30 March-1 April. doi: 10.2118/92049-MS.
Lea, J.F., Nickens, H.V., and Wells, M.R. 2003. Gas WellDeliquification, first edition, 2-4. Burlington, Massachusetts: GulfProfessional Publishing, Elsevier.
McCain, W.D. Jr. 1990. The Properties of Petroleum Fluids, secondedition. Tulsa, Oklahoma: PennWell Publishing Company.
Nosseir, M.A., Darwich, T.A., Sayyouh, M.H., and El Sallaly, M. 2000. A New Approach for AccuratePrediction of Loading in Gas Wells Under Different Flowing Conditions.SPE Prod & Fac 15 (4): 241-246. SPE-66540-PA. doi:10.2118/66540-PA.
Standing, M.B. 1981. Volumetric and Phase Behavior of Oil FieldHydrocarbon Systems, ninth edition. Richardson, Texas: Society of PetroleumEngineers of AIME.
Taitel, Y., Barnea, D., and Duckler, A.E. 1980. Modelling flow patterntransitions for steady upward gas-liquid flow in vertical tubes. AIChEJournal 26 (3): 345-354. doi:10.1002/aic.690260304.
Turner, R.G., Hubbard, M.G., and Dukler, A.E. 1969. Analysis and Prediction of MinimumFlowrate for the Continuous Removal of Liquids from Gas Wells. J PetTechnol 21 (11): 1475-1482; Trans., AIME, 246.SPE-2198-PA. doi: 10.2118/2198-PA.
Wallis, G.B. 1969. One Dimensional Two-Phase Flow. New York:McGraw-Hill.