Experimental Validation of a Pore-Scale Derived Dimensionless Capillary Pressure Function for Imbibition Under Mixed-Wet Conditions

Yingfang Zhou, J. O. Helland, D. G. Hatzignatiou, R. Ahsan, A. Hiorth

Research output: Contribution to conferencePaper

Abstract

In this work, we validate experimentally a dimensionless capillary pressure function for imbibition at mixed-wet conditionsthat we developed recently based on pore-scale modeling in rock images. The difference to Leverett's traditional J-function is that our dimensionless function accounts for wettability and initial water saturation after primary drainage through area-averaged, effective contact angles that depend on the wetting property and distribution of oil- and water-wet grain surfaces. We hypothesized that describing these effective contact angles as a function of Amott wettability index relates the pore- and core-scale wettability, and that pore-scale imbibition simulations can provide these relations for specific rocks. In the present work, we adopt the dimensionless function to scale imbibition capillary pressure data measured on mixed-wet sandstone and chalk cores. The measured data practically collapse to a unique curve when subjected to the dimensionless capillary pressure function. For each rock material, we employ the average, dimensionless curve to reproduce the measured capillary pressure curves and obtain excellent agreement. We also demonstrate two approaches to generate different capillary pressure curves at other mixed-wettability states than that available from the data used to generate the dimensionless curve. The first approach changes the shape of the spontaneous- and forced-imbibition segments of the capillary pressure curve while the saturation at zero capillary pressure is constant. The second approach shifts the vertical level of the entire capillary pressure curve, such that the Amott wetting index (and the saturation at zero capillary pressure) changes accordingly. Thus, integrating these two approaches with the dimensionless function yields increased flexibility to account for different mixed-wettability states. The validated dimensionless function scales mixed-wet capillary pressure curves from core samples accurately, which demonstrates its applicability to describe variations of wettability and permeability with capillary pressure in reservoir simulation models. This allows for improved utilization of core experiments in predicting reservoir performance. Reservoir simulation models can also employ the dimensionless function together with existing capillary pressure correlations.
Original languageEnglish
Publication statusPublished - 2016
Event78th EAGE Conference and Exhibition 2016: Efficient Use of Technology - Unlocking Potential2016 - Reed Messe Wien Vienna; Austria, Vienna, Austria
Duration: 30 May 20162 Jun 2016
Conference number: 127575

Conference

Conference78th EAGE Conference and Exhibition 2016
CountryAustria
CityVienna
Period30/05/162/06/16

Fingerprint

imbibition
Capillarity
capillary pressure
porosity
Wetting
wettability
curves
Saturation (materials composition)
Rocks
saturation
rocks
wetting
Contact angle
rock
chalk
simulation
Core samples
Water
Calcium Carbonate
sandstones

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

Cite this

Zhou, Y., Helland, J. O., Hatzignatiou, D. G., Ahsan, R., & Hiorth, A. (2016). Experimental Validation of a Pore-Scale Derived Dimensionless Capillary Pressure Function for Imbibition Under Mixed-Wet Conditions. Paper presented at 78th EAGE Conference and Exhibition 2016, Vienna, Austria.

Experimental Validation of a Pore-Scale Derived Dimensionless Capillary Pressure Function for Imbibition Under Mixed-Wet Conditions. / Zhou, Yingfang; Helland, J. O.; Hatzignatiou, D. G.; Ahsan, R.; Hiorth, A. .

2016. Paper presented at 78th EAGE Conference and Exhibition 2016, Vienna, Austria.

Research output: Contribution to conferencePaper

Zhou, Y, Helland, JO, Hatzignatiou, DG, Ahsan, R & Hiorth, A 2016, 'Experimental Validation of a Pore-Scale Derived Dimensionless Capillary Pressure Function for Imbibition Under Mixed-Wet Conditions' Paper presented at 78th EAGE Conference and Exhibition 2016, Vienna, Austria, 30/05/16 - 2/06/16, .
Zhou Y, Helland JO, Hatzignatiou DG, Ahsan R, Hiorth A. Experimental Validation of a Pore-Scale Derived Dimensionless Capillary Pressure Function for Imbibition Under Mixed-Wet Conditions. 2016. Paper presented at 78th EAGE Conference and Exhibition 2016, Vienna, Austria.
Zhou, Yingfang ; Helland, J. O. ; Hatzignatiou, D. G. ; Ahsan, R. ; Hiorth, A. . / Experimental Validation of a Pore-Scale Derived Dimensionless Capillary Pressure Function for Imbibition Under Mixed-Wet Conditions. Paper presented at 78th EAGE Conference and Exhibition 2016, Vienna, Austria.
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