Enhanced permeability due to apparent oil/brine slippage in limestone and its dependence on wettability

M. Christensen, Y. Tanino

Research output: Contribution to journalArticle

7 Citations (Scopus)
4 Downloads (Pure)

Abstract

End point relative permeabilities were measured in three limestones with permeabilities ranging from 0.6 to 220 mD under five wettability states established by adding different organic acids, of similar molecular structure but different alkyl chain length, to the oil phase. The altered wettability corresponding to each oil/brine pair is characterized by their dynamic contact angle on a polished calcite substrate, θw, which varied between 50° and 150°. Saturation-normalized relative permeability to oil exceeds one at θw<140° in all rock considered. The equivalent slip length, defined by modeling the porous medium as a capillary tube with the defending phase distributed as an annular film on the tube wall, was below 200 nm in all experiments. The results indicate that commonly used models of relative permeability, which assume that the maximum permeability is the single-phase permeability, underestimate oil displacement for a much wider range of contact angles than previously documented.
Original languageEnglish
Pages (from-to)6116-6123
Number of pages8
JournalGeophysical Research Letters
Volume44
Issue number12
Early online date28 Jun 2017
DOIs
Publication statusPublished - 17 Jul 2017

Fingerprint

wettability
limestone
brine
permeability
oils
oil
capillary tubes
calcite
organic acid
porous medium
slip
molecular structure
saturation
rocks
tubes
substrate
acids
rock
modeling
experiment

Keywords

  • multiphase flow
  • slip
  • wettability
  • hydrophobic surfaces
  • relative permeability

Cite this

Enhanced permeability due to apparent oil/brine slippage in limestone and its dependence on wettability. / Christensen, M.; Tanino, Y.

In: Geophysical Research Letters, Vol. 44, No. 12, 17.07.2017, p. 6116-6123.

Research output: Contribution to journalArticle

@article{db074f9493ea479d8791bc665f5e5363,
title = "Enhanced permeability due to apparent oil/brine slippage in limestone and its dependence on wettability",
abstract = "End point relative permeabilities were measured in three limestones with permeabilities ranging from 0.6 to 220 mD under five wettability states established by adding different organic acids, of similar molecular structure but different alkyl chain length, to the oil phase. The altered wettability corresponding to each oil/brine pair is characterized by their dynamic contact angle on a polished calcite substrate, θw, which varied between 50° and 150°. Saturation-normalized relative permeability to oil exceeds one at θw<140° in all rock considered. The equivalent slip length, defined by modeling the porous medium as a capillary tube with the defending phase distributed as an annular film on the tube wall, was below 200 nm in all experiments. The results indicate that commonly used models of relative permeability, which assume that the maximum permeability is the single-phase permeability, underestimate oil displacement for a much wider range of contact angles than previously documented.",
keywords = "multiphase flow, slip, wettability, hydrophobic surfaces, relative permeability",
author = "M. Christensen and Y. Tanino",
note = "Acknowledgments This material includes work supported by a Society of Petrophysicists and Well Log Analysts Foundation grant and an Aberdeen Formation Evaluation Society scholarship. M.C. was supported by a University of Aberdeen College of Physical Sciences studentship. The authors gratefully acknowledge Amer Syed for his assistance with the assembly and maintenance of the coreflood rigs, Jim Anderson for helpful discussions, and the two anonymous reviewers for their comments and suggestions. All data used in this study will be made available from the corresponding author upon request.",
year = "2017",
month = "7",
day = "17",
doi = "10.1002/2017GL073603",
language = "English",
volume = "44",
pages = "6116--6123",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "AMER GEOPHYSICAL UNION",
number = "12",

}

TY - JOUR

T1 - Enhanced permeability due to apparent oil/brine slippage in limestone and its dependence on wettability

AU - Christensen, M.

AU - Tanino, Y.

N1 - Acknowledgments This material includes work supported by a Society of Petrophysicists and Well Log Analysts Foundation grant and an Aberdeen Formation Evaluation Society scholarship. M.C. was supported by a University of Aberdeen College of Physical Sciences studentship. The authors gratefully acknowledge Amer Syed for his assistance with the assembly and maintenance of the coreflood rigs, Jim Anderson for helpful discussions, and the two anonymous reviewers for their comments and suggestions. All data used in this study will be made available from the corresponding author upon request.

PY - 2017/7/17

Y1 - 2017/7/17

N2 - End point relative permeabilities were measured in three limestones with permeabilities ranging from 0.6 to 220 mD under five wettability states established by adding different organic acids, of similar molecular structure but different alkyl chain length, to the oil phase. The altered wettability corresponding to each oil/brine pair is characterized by their dynamic contact angle on a polished calcite substrate, θw, which varied between 50° and 150°. Saturation-normalized relative permeability to oil exceeds one at θw<140° in all rock considered. The equivalent slip length, defined by modeling the porous medium as a capillary tube with the defending phase distributed as an annular film on the tube wall, was below 200 nm in all experiments. The results indicate that commonly used models of relative permeability, which assume that the maximum permeability is the single-phase permeability, underestimate oil displacement for a much wider range of contact angles than previously documented.

AB - End point relative permeabilities were measured in three limestones with permeabilities ranging from 0.6 to 220 mD under five wettability states established by adding different organic acids, of similar molecular structure but different alkyl chain length, to the oil phase. The altered wettability corresponding to each oil/brine pair is characterized by their dynamic contact angle on a polished calcite substrate, θw, which varied between 50° and 150°. Saturation-normalized relative permeability to oil exceeds one at θw<140° in all rock considered. The equivalent slip length, defined by modeling the porous medium as a capillary tube with the defending phase distributed as an annular film on the tube wall, was below 200 nm in all experiments. The results indicate that commonly used models of relative permeability, which assume that the maximum permeability is the single-phase permeability, underestimate oil displacement for a much wider range of contact angles than previously documented.

KW - multiphase flow

KW - slip

KW - wettability

KW - hydrophobic surfaces

KW - relative permeability

U2 - 10.1002/2017GL073603

DO - 10.1002/2017GL073603

M3 - Article

VL - 44

SP - 6116

EP - 6123

JO - Geophysical Research Letters

JF - Geophysical Research Letters

SN - 0094-8276

IS - 12

ER -