Capillarity and rapid flow effects on gas condensate well tests

  • José Humberto Cantillo Ecopetrol S.A. – Instituto Colombiano del Petróleo, A.A. 4185 Bucaramanga, Santander, Colombia
  • Freddy Humberto Escobar Universidad Surcolombiana, Programa de Ingeniería de Petróleos, Grupo de Investigación en Pruebas de Pozos, Neiva, Huila, Colombia
  • Oscar Fernando Muñoz Universidad Surcolombiana, Programa de Ingeniería de Petróleos, Grupo de Investigación en Pruebas de Pozos, Neiva, Huila, Colombia
Keywords: nondarcy flow, interfacial tension, capillary phenomenon, gas condensate reservoir

Abstract

The state-of-the-art of gas condensate well tests for pressures below the dewpoint are basically based upon a two-zone composite radial model, which consists of a near-wellbore region having liquid condensation and a monophasic flow zone with no gas condensate saturation.  Information obtained from laboratory tests suggests the presence of three zones having different fluid mobilities: (1) a far region from the well with initial liquid condensate saturation of zero, (2) a near wellbore zone having an increased condensate saturation and a reduced gas mobility, and (3) an intermediate zone from the well with both high capillary and increasing gas relative permeability which leads to gas mobility restoring due to condensate blocking. The gas condensate saturation is higher than its critical value, then the condensate phase is mobile.  In this study, both the rapid flow and capillary number effects on gas condensate reservoirs from well pressure test data are dealt with. We observed that the nondarcy effect originates additional pressure drop which is proportional to the flow rate while, the capillary number causes a reduction of condensate saturation in the near wellbore area and the reservoir providing a negative skin factor which contributes to fluid mobility, and therefore, production. Besides that, we also included the possitive coupled effect, defined here as the simoultaneous action of nondarcy flow and capillary number; which is more relevant at relatively low gas rates. We found out that the capillary number dominates the nondarcy effect leading to a reduction in condensate saturation.

References

Fevang, O., & Whitson, C. H. (1995). Modeling gas condensate well deliverability. SPE Annual Technical Conference and Exhibition, Dallas, Texas, Oct. 22-25. SPE 30714.

Gringarten, A. C., Al-Lamki, A., Daungkaew, S., Mott, R., & Whittle, T.M. (2000). Well test analysis in gas-condensate reservoirs. SPE Annual Technical Conference and Exhibition, Dallas, Texas, Oct. 1-4. SPE 62920. https://doi.org/10.2118/62920-MS

Jokhio, S. A. (2002). Production performance of horizontal wells in gas-condensate reservoirs. Ph.D. Dissertation, The University of Oklahoma, Norman, Oklahoma, USA.

Li, D., & Engler, T. W. (2001). Literature review on correlations of the nondarcy coefficient. SPE Permian Basin Oil and Gas Recovery Conference, Midland, Texas, May 15-16. SPE 70015. https://doi.org/10.2118/70015-MS

Raghavan, R., Wei-Chun, Ch., & Jones, J.R. (1995). Practical considerations in the analysis of gas-condensate well tests. SPE Annual Technical Conference and Exhibition, Dallas, Texas, Oct. 22-25. SPE 30576. https://doi.org/10.2118/30576-MS

Xu, S., & Lee, W. J. (1999a). Gas condensate well test analysis using a single-phase analogy. SPE Western Regional Meeting, Anchorage, Alaska, May 26-28. SPE 55992. https://doi.org/10.2118/55992-MS

Xu, S., & Lee W. J. (1999b). Two-phase well test analysis of gas condensate reservoirs. SPE Annual Technical Conference and Exhibition, Houston, Texas, Oct. 3-6. SPE 56483. https://doi.org/10.2118/56483-MS

How to Cite
Cantillo, J. H., Escobar, F. H., & Muñoz, O. F. (2010). Capillarity and rapid flow effects on gas condensate well tests. CT&F - Ciencia, Tecnología Y Futuro, 3(2), 73–82. https://doi.org/10.29047/01225383.492

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Published
2010-06-30
Section
Scientific and Technological Research Articles

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