Grid-system requirements in numerical modeling of pressure-transient tests in horizontal wells

Nasser Al Mohanadi, Erdal Ozkan, Hassein Kazemi

Research output: Contribution to journalArticle

8 Citations (Scopus)


The common approach of using refined grids and small timesteps usually does not provide accurate and efficient numerical models to simulate horizontal-well pressure-transient tests. In most cases, this approach requires impracticably long computational times or creates artifacts on pressure and derivative responses that may be confused with the characteristics of certain flow regimes. This paper presents an investigation of the grid and timestep requirements for the conventional well index (WI) to provide accurate simulations of horizontal-well pressure-transient responses. The results of this study indicate that the conventional WI should be used with log-distributed grid and timesteps to obtain a closer match to the analytical solution at early times. There is a limit to grid refinement beyond which the results do not improve. For these cases, the transient well index (TWI) introduced in this paper allows larger grids while improving the accuracy of simulations, especially at early times.

Original languageEnglish
Pages (from-to)122-131
Number of pages10
JournalSPE Reservoir Evaluation and Engineering
Issue number2
Publication statusPublished - Apr 2007


ASJC Scopus subject areas

  • Fuel Technology
  • Energy Engineering and Power Technology
  • Geology

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