TY - JOUR
T1 - An experimental study to investigate novel physical mechanisms that enhance viscoelastic polymer flooding and further increase desaturation of residual oil saturation
AU - Irfan, Md
AU - Stephen, Karl D.
AU - Lenn, Christopher P.
N1 - Funding Information:
This work was supported by the grant titled Exploration Technology GR&T CSI/UTP (XTECH-CSI) R&D Collaboration from PETRONAS. Irfan acknowledges useful email discussions with Prof. Dr. Andrew Clarke, Prof. Dr. Martin Blunt, Prof. Dr. Randy H. Ewoldt and Dr. Raj Dev Tewari for many useful discussions to the idea of this manuscript. Authors thank TA Instruments experts for the initial discussions on a variety of experimental artifacts for rheological measurements. The authors sincerely thank Bruno Giovannetti and his team members at SNF Floerger, France for providing polymer samples used in this work. The authors thank Mr. Richard Siew (Dixson Company, Malaysia), Mr. Amir (Vinci Technologies) and Mr. Hazri (Flow Assurance Laboratory, UTP), Mr. Annas and Mr. Iswadi for preparing these samples and performing the rheometer experiment. Irfan acknowledges a special thanks to Dr. Ismail (UTP) for Core-flooding experiment at his laboratory. We acknowledge Dr. Khaled (UTP) for his valuable support. Irfan fully dedicates this work to his main supervisor Late Prof. Deva Prasad Ghosh.
Funding Information:
This document is the results of the research project funded by the Petroliam Nasional Berhad (PETRONAS), Malaysia.
Funding Information:
This work was supported by the grant titled Exploration Technology GR&T CSI/UTP (XTECH-CSI) R&D Collaboration from PETRONAS. Irfan acknowledges useful email discussions with Prof. Dr. Andrew Clarke, Prof. Dr. Martin Blunt, Prof. Dr. Randy H. Ewoldt and Dr. Raj Dev Tewari for many useful discussions to the idea of this manuscript. Authors thank TA Instruments experts for the initial discussions on a variety of experimental artifacts for rheological measurements. The authors sincerely thank Bruno Giovannetti and his team members at SNF Floerger, France for providing polymer samples used in this work. The authors thank Mr. Richard Siew (Dixson Company, Malaysia), Mr. Amir (Vinci Technologies) and Mr. Hazri (Flow Assurance Laboratory, UTP), Mr. Annas and Mr. Iswadi for preparing these samples and performing the rheometer experiment. Irfan acknowledges a special thanks to Dr. Ismail (UTP) for Core-flooding experiment at his laboratory. We acknowledge Dr. Khaled (UTP) for his valuable support. Irfan fully dedicates this work to his main supervisor Late Prof. Deva Prasad Ghosh.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/2
Y1 - 2021/2
N2 - This study uses a combination of shear rheometry and core-flooding using viscoelastic polymers to understand better the enhanced oil sweep efficiency after residual oil saturation is achieved by conventional water-flood. This work addresses the question of anomalous (enhanced) desaturation of oil by water-flooding using polymer and which has been widely reported since 2008. A mechanism to explain the enhanced desaturation is developed. Berea sandstone was saturated with synthetic oil (34mPa.s @ 200 C) at set reservoir conditions (2000 psi, 900 C). It was water-flooded from initial oil saturation (Soi=76.21 %, 47.5 ml) to residual oil saturation (Sorw=40.43 %, 25.2 ml) where oil cut was zero using brine (33390 ppm). The core was subject to further flooding using inelastic Newtonian 85 wt % Glycerol flooding until zero oil cut (Sorgly=36.90 %, 23.0 ml), followed by viscous Non-Newtonian 1720 ppm Xanthan Gum flooding (Sorx=34.33 %, 21.4 ml), followed by 6000 ppm viscoelastic FLOPAAM 3230 (Sor3230=34.33 %, 21.4 ml, zero oil cut) and ended by 2000 ppm FLOCOMB 6525 (Sor6525=33.21 %, 20.7 ml). It was found an additional 3.27% OOIP was recovered by the elastic turbulence effect of high Mw viscoelastic polymer-flooding below critical Capillary number, having the Deborah number, NDe=2.13. Since the late 1960s, EOR researchers have developed different continuum and pore-scale viscoelastic models for quantifying the viscoelastic polymer-flooding effects on Sor. From the literature, research articles conclude that Sor reduction depends upon the flux rate as well as on reservoir wettability, brine salinity, reservoir permeability, polymer elasticity, Mw of viscoelastic polymer and oil viscosity. We have come to the conclusion in this paper that despite these noteworthy Sor reduction explanations, the mechanism of quantified Sor reduction by viscoelastic effect is as yet an unresolved mechanism that requires further investigation. We conclude that the proposed elastic turbulence mechanism has played an important role in the occurrence of increased pore-level induced pressure fluctuations, which in turn increases velocity rate fluctuations and hence additional desaturation of immobile residual oil.
AB - This study uses a combination of shear rheometry and core-flooding using viscoelastic polymers to understand better the enhanced oil sweep efficiency after residual oil saturation is achieved by conventional water-flood. This work addresses the question of anomalous (enhanced) desaturation of oil by water-flooding using polymer and which has been widely reported since 2008. A mechanism to explain the enhanced desaturation is developed. Berea sandstone was saturated with synthetic oil (34mPa.s @ 200 C) at set reservoir conditions (2000 psi, 900 C). It was water-flooded from initial oil saturation (Soi=76.21 %, 47.5 ml) to residual oil saturation (Sorw=40.43 %, 25.2 ml) where oil cut was zero using brine (33390 ppm). The core was subject to further flooding using inelastic Newtonian 85 wt % Glycerol flooding until zero oil cut (Sorgly=36.90 %, 23.0 ml), followed by viscous Non-Newtonian 1720 ppm Xanthan Gum flooding (Sorx=34.33 %, 21.4 ml), followed by 6000 ppm viscoelastic FLOPAAM 3230 (Sor3230=34.33 %, 21.4 ml, zero oil cut) and ended by 2000 ppm FLOCOMB 6525 (Sor6525=33.21 %, 20.7 ml). It was found an additional 3.27% OOIP was recovered by the elastic turbulence effect of high Mw viscoelastic polymer-flooding below critical Capillary number, having the Deborah number, NDe=2.13. Since the late 1960s, EOR researchers have developed different continuum and pore-scale viscoelastic models for quantifying the viscoelastic polymer-flooding effects on Sor. From the literature, research articles conclude that Sor reduction depends upon the flux rate as well as on reservoir wettability, brine salinity, reservoir permeability, polymer elasticity, Mw of viscoelastic polymer and oil viscosity. We have come to the conclusion in this paper that despite these noteworthy Sor reduction explanations, the mechanism of quantified Sor reduction by viscoelastic effect is as yet an unresolved mechanism that requires further investigation. We conclude that the proposed elastic turbulence mechanism has played an important role in the occurrence of increased pore-level induced pressure fluctuations, which in turn increases velocity rate fluctuations and hence additional desaturation of immobile residual oil.
KW - Critical capillary number
KW - Deborah number
KW - Elastic turbulence
KW - Enhanced oil recovery
KW - Shear rheometry
KW - Viscoelastic polymer-flooding
UR - http://www.scopus.com/inward/record.url?scp=85123935972&partnerID=8YFLogxK
U2 - 10.1016/j.upstre.2020.100026
DO - 10.1016/j.upstre.2020.100026
M3 - Article
AN - SCOPUS:85123935972
SN - 2666-2604
VL - 6
JO - Upstream Oil and Gas Technology
JF - Upstream Oil and Gas Technology
M1 - 100026
ER -