• norsk
    • English
  • norsk 
    • norsk
    • English
  • Logg inn
Vis innførsel 
  •   Hjem
  • Fakultet for ingeniørvitenskap (IV)
  • Institutt for geovitenskap og petroleum
  • Vis innførsel
  •   Hjem
  • Fakultet for ingeniørvitenskap (IV)
  • Institutt for geovitenskap og petroleum
  • Vis innførsel
JavaScript is disabled for your browser. Some features of this site may not work without it.

Well test analysis, application to thermal recovery processes for reservoir characterization

Ghahfarokhi, Ashkan Jahanbani
Doctoral thesis
Åpne
Fulltext not available (Låst)
Permanent lenke
http://hdl.handle.net/11250/283768
Utgivelsesdato
2015
Metadata
Vis full innførsel
Samlinger
  • Institutt for geovitenskap og petroleum [1883]
Sammendrag
Thermal recovery by steam injection is considered to be a promising method for

achieving a high ultimate recovery. A composite reservoir may occur during any

enhanced oil recovery (EOR) project like steam injection into an oil reservoir. Thermal

falloff test analysis offers a quick way to obtain an estimate of the swept volume and

steam zone properties. Most of the models used for the analysis assume two regioncomposite

reservoirs with different but uniform properties separated by a sharp vertical

interface which is not very realistic.

Numerical simulation study of steam injection in both vertical and horizontal wells

(SAGD well pairs) was done to evaluate the applicability and accuracy of thermal well

test analysis method and effects of several parameters on the results. Primary results

showed that quite reasonable estimates were obtained. Some trends seen on the pressure

plots, however, cannot be explained using the existing models and there are errors

associated with the volume estimates that could be related to the simplifying

assumptions of the conventional models. Therefore, the main objective of this PhD

project is to develop a new analytical model for pressure transient analysis of composite

reservoirs to improve previous models with inclusion of some parameters and more

realistic assumptions. Two models are presented.

In the models proposed, the interface separating the two regions is not sharp. Instead,

there is an intermediate region between the inner and the outer region in which mobility

and storativity decrease smoothly, as power-law functions of the radial distance from

the first interface. The interfaces are considered to be tilted due to gravity effects. A

single-layer model with continuous tilted front is assumed in the first model. In

addition, tilted front is modeled using the conventional way of treating the gas override

by assuming a multi-layer reservoir model in the second model of this study. Inclusion

of steam condensation in the form of heat loss from the steam zone to the surroundings

was first studied numerically with the conclusion that in the case of huge heat loss,

pressure data are significantly affected and method of analysis should change. Heat loss

effect is therefore included in the analytical models of this work. In another effort, a

conventional multi-region model is improved to include the effect of gravity. This

model with some modifications can finally match the models presented in this thesis

within reasonable accuracy.

The new sets of type curves for thermal well test interpretation are generated and

verified against some conventional models. Effects of several parameters included in the

models on the shape of type curves are discussed. The models developed can be used to

predict the pressure behavior in thermal recovery processes and estimate reservoir

properties using type curve matching instead of the conventional pseudo steady state method. The method is general and can be applied to other types of composite

reservoirs.
Utgiver
NTNU
Serie
Doctoral thesis at NTNU;2015:41

Kontakt oss | Gi tilbakemelding

Personvernerklæring
DSpace software copyright © 2002-2019  DuraSpace

Levert av  Unit
 

 

Bla i

Hele arkivetDelarkiv og samlingerUtgivelsesdatoForfattereTitlerEmneordDokumenttyperTidsskrifterDenne samlingenUtgivelsesdatoForfattereTitlerEmneordDokumenttyperTidsskrifter

Min side

Logg inn

Statistikk

Besøksstatistikk

Kontakt oss | Gi tilbakemelding

Personvernerklæring
DSpace software copyright © 2002-2019  DuraSpace

Levert av  Unit