Optimum Timing for CO2-EOR After Waterflooding and Soaking Effect on Miscible CO2 Flooding in a Tight Sandstone Formation,
type: CreativeWork
description: In continuous CO2 secondary flooding, severe viscous fingering and early CO2 breakthrough (BT) occur due to an unfavourable mobility contrast between the injected CO2 and the crude oil. The oil recovery is limited after CO2 BT, which is attributed to the gas channeling problem. In continuous CO2 tertiary flooding, the previously injected water helps to control the mobility of the subsequently injected CO2. On the other hand, it hinders the mutual interactions between the residual oil and the subsequently injected CO2 and thus affects the tertiary oil recovery. This thesis experimentally studied the mutual interactions between the light oil/reservoir brine and CO2 and the technical optimization of CO2 enhanced oil recovery (CO2-EOR) process, which included the optimum timing for CO2-EOR after waterflooding and soaking effect on miscible CO2 flooding in a tight sandstone formation. First, the saturation pressure (Psat), oil-swelling factor (SF), gas–oil ratio (GOR) of CO2- saturated light oil, and gas–water ratio (GWR) of CO2-saturated reservoir brine were measured by using a PVT system. Second, the viscosities of CO2-saturated light oil with different CO2 concentrations were measured by using a capillary viscometer. Third, the equilibrium interfacial tensions (IFTs) between the light oil/reservoir brine and CO2 were measured at different equilibrium pressures and the actual reservoir temperature by applying the axisymmetric drop shape analysis (ADSA) technique for the pendant oil drop case. Finally, five coreflood tests were performed to determine the optimum timing for miscible CO2-EOR after waterflooding and six coreflood tests were conducted to examine CO2-soaking effect on miscible CO2 flooding in a tight sandstone formation, respectively. The experimental results showed that Psat and oil SF of CO2-saturated light oil were increased respectively in the ranges of 4.97–8.44 MPa and 1.14–1.34 when CO2 concentration in the light oil–CO2 system was increased in the ra…
abstract: In continuous CO2 secondary flooding, severe viscous fingering and early CO2 breakthrough (BT) occur due to an unfavourable mobility contrast between the injected CO2 and the crude oil. The oil recovery is limited after CO2 BT, which is attributed to the gas channeling problem. In continuous CO2 tertiary flooding, the previously injected water helps to control the mobility of the subsequently injected CO2. On the other hand, it hinders the mutual interactions between the residual oil and the subsequently injected CO2 and thus affects the tertiary oil recovery. This thesis experimentally studied the mutual interactions between the light oil/reservoir brine and CO2 and the technical optimization of CO2 enhanced oil recovery (CO2-EOR) process, which included the optimum timing for CO2-EOR after waterflooding and soaking effect on miscible CO2 flooding in a tight sandstone formation. First, the saturation pressure (Psat), oil-swelling factor (SF), gas–oil ratio (GOR) of CO2- saturated light oil, and gas–water ratio (GWR) of CO2-saturated reservoir brine were measured by using a PVT system. Second, the viscosities of CO2-saturated light oil with different CO2 concentrations were measured by using a capillary viscometer. Third, the equilibrium interfacial tensions (IFTs) between the light oil/reservoir brine and CO2 were measured at different equilibrium pressures and the actual reservoir temperature by applying the axisymmetric drop shape analysis (ADSA) technique for the pendant oil drop case. Finally, five coreflood tests were performed to determine the optimum timing for miscible CO2-EOR after waterflooding and six coreflood tests were conducted to examine CO2-soaking effect on miscible CO2 flooding in a tight sandstone formation, respectively. The experimental results showed that Psat and oil SF of CO2-saturated light oil were increased respectively in the ranges of 4.97–8.44 MPa and 1.14–1.34 when CO2 concentration in the light oil–CO2 system was increased in the ra…
author: Li, Zeya
language: en
date published: 2014-04
date modified: 2026-07-24T04:03:30Z
provider: University of Regina
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Faculty of Graduate Studies and Research, University of Regina

PropertyValue
property ID: Handle
value: https://hdl.handle.net/10294/5769

PropertyValue
property ID: DOI
value: 10.82465/4021