To main content

Reactive instabilities in linear acidizing on carbonates

Abstract

Acid injection, reactive instabilities and wormholing in carbonate reservoirs is investigated through the
analysis of the linear acidizing problem theoretically and experimentally. Theoretically acidizing was
analyzed by formulating the problem as a reactive moving boundary Stefan type problem. Wormholing
is viewed as a reactive infiltration instability to the trivial solution of uniform dissolution. A linear
stability analysis from the equilibrium state is performed and the critical wavenumber below which
instabilities have a positive growth rate is identified. When applied to the scale of the experiment,
an optimum injection velocity is identified for a given formation and injection concentration, for
the growth for a single wormhole. This optimum injection velocity scales with the inverse of the
specimen diameter. Experimentally, linear acidizing tests were performed in Mons chalk, a high
porosity analogue of North Sea reservoir chalk. In the experiments the critical injection velocity for
wormhole formation at minimum acid injection was obtained and the results were compared with
the theoretical predictions.
Read the publication

Category

Academic article

Language

English

Author(s)

Affiliation

  • SINTEF Industry / Applied Geoscience
  • Aristotle University of Thessaloniki
  • Aker BP ASA

Year

2020

Published in

Geomechanics for Energy and the Environment

ISSN

2352-3808

Volume

21

View this publication at Norwegian Research Information Repository