Effect of Heat Loss on Pressure Falloff Tests

Effect of Heat Loss on Pressure Falloff Tests

  IJETT-book-cover  International Journal of Engineering Trends and Technology (IJETT)          
  
© 2016 by IJETT Journal
Volume-39 Number-1
Year of Publication : 2016
Authors : Ashkan Jahanbani G., Tom A. Jelmert
DOI :  10.14445/22315381/IJETT-V39P205

Citation 

Ashkan Jahanbani G., Tom A. Jelmert"Effect of Heat Loss on Pressure Falloff Tests", International Journal of Engineering Trends and Technology (IJETT), V39(1),28-36 September 2016. ISSN:2231-5381. www.ijettjournal.org. published by seventh sense research group

Abstract
Analysis of pressure falloff tests gives initial estimates of swept volume, essential for the evaluation of a thermal recovery process. The analysis is conventionally based on a two-zone composite reservoir model with highly contrasting fluid mobilities where the swept zone is assumed to behave as a closed reservoir for a short period exhibiting pseudo steady state behavior. The upward buckling of the pressure derivative curves at late times in some cases could not be explained using the conventional composite models. This issue and some of the errors associated with the estimation of swept volume may possibly be related to heat loss which could have significant effects on the pressure behavior and dominate the pseudo steady state flow. A few models were suggested for the analysis of falloff tests with significant heat loss, however they are limited in application. Moreover, permeability should be known in advance for further analysis. In this paper, a modified method of analysis considering heat loss is discussed which makes the flow regime identification easier and removes some of the practical limitations. Results of the analysis show improvement over the estimates obtained by other methods.

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Keywords
pressure falloff test, thermal methods, composite reservoir, heat loss.