Sequential Injection of Carbonated Water: A Possible Process for Coupling CO2 Enhanced Oil Recovery and Storage

Low salinity and carbonated water flooding have been investigated as possible techniques of improved/enhanced oil recovery. Carbonated water injection consists of dissolving carbon dioxide CO2 in water prior to injection and could be considered as a way to store greenhouse gas safely. Low salinity water flooding is a process of diluting high salinity injection water to a very low level of salinity. In this project, the effect of combining the two techniques in a sequential flooding was studied. The primary aim of this study is to optimize the oil recovery and evaluate CO2 storage during this process, employing low permeability carbonate cores and different sequential carbonated and non-carbonated brines flooding. Formation brine, seawater, low salinity carbonated and non-carbonated were used in this work. Core samples grouped as composite cores with similar over all reservoir permeability. Different sequences of brines were employed to determine the optimum system. The experiment's result showed that carbonated water performs better than the noncarbonated brines. A new technique for estimate CO2 retention based on the displacement efficiency of the carbonated water flooding system is presented. The interfacial tension, contact angle measurements results indicated that wettability is the dominant mechanism of the studied systems. A sequential composite core flooding consists of carbonated low salinity followed by low salinity and seawater injection (CLSW- LSW-SW) is the optimum flooding system among the studied systems. Technically, CLSW flooding displayed an excellent incremental displacement efficiency ∆DE of 21.4% and CSW exhibited the best CO2 retention per incremental ∆Np.

Download Full-text

Enhanced Oil Recovery and CO2 Storage by Carbonated Water Injection

Proceedings of International Petroleum Technology Conference ◽

10.2523/14070-abstract ◽

2009 ◽

Author(s):

Mehran Sohrabi ◽

Masoud Riazi ◽

Mahmoud Jamiolahmady ◽

Shaun Ireland ◽

Christopher Brown

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Co2 Storage ◽

Water Injection ◽

Carbonated Water Injection ◽

Carbonated Water

Download Full-text

Numerical modeling and experimental investigation on the effect of low-salinity water flooding for enhanced oil recovery in carbonate reservoirs

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-020-01071-4 ◽

2021 ◽

Vol 11 (2) ◽

pp. 925-947

Author(s):

Erfan Hosseini ◽

Mohammad Sarmadivaleh ◽

Dana Mohammadnazar

Keyword(s):

Oil Recovery ◽

Water Injection ◽

Water Flooding ◽

Wettability Alteration ◽

Experimental Investigations ◽

Core Flooding ◽

Reservoir Temperature ◽

Sulfate Ion ◽

Ionic Content ◽

Low Salinity

AbstractNumerous studies concluded that water injection with modified ionic content/salinity in sandstones would enhance the oil recovery factor due to some mechanisms. However, the effects of smart water on carbonated formations are still indeterminate due to a lack of experimental investigations and researches. This study investigates the effects of low-salinity (Low Sal) solutions and its ionic content on interfacial tension (IFT) reduction in one of the southwestern Iranian carbonated reservoirs. A set of organized tests are designed and performed to find each ion’s effects and total dissolved solids (TDS) on the candidate carbonated reservoir. A sequence of wettability and IFT (at reservoir temperature) tests are performed to observe the effects of controlling ions (sulfate, magnesium, calcium, and sodium) and different salinities on the main mechanisms (i.e., wettability alteration and IFT reduction). All IFT tests are performed at reservoir temperature (198 °F) to minimize the difference between reservoir and laboratory-observed alterations. In this paper, the effects of four different ions (SO42-, Ca2+, Mg2+, Na+) and total salinity TDS (40,000, 20,000, 5000 ppm) are investigated. From all obtained results, the best two conditions are applied in core flooding tests to obtain the relative permeability alterations using unsteady-state methods and Cydarex software. The final part is the simulation of the whole process using the Schlumberger Eclipse black oil simulator (E100, Ver. 2010) on the candidate reservoir sector. To conclude, at Low Sal (i.e., 5000 ppm), the sulfate ion increases sulfate concentration lower IFT, while in higher salinities, increasing sulfate ion increases IFT. Also, increasing calcium concentration at high TDS (i.e., 40,000 ppm) decreases the amount of wettability alteration. In comparison, in lower TDS values (20,000 and 5000 ppm), calcium shows a positive effect, and its concentration enhanced the alteration process. Using Low Sal solutions at water cut equal or below 10% lowers recovery rate during simulations while lowering the ultimate recovery of less than 5%.

Download Full-text

Enhanced Oil Recovery and CO2 Storage by Carbonated Water Injection

10.3997/2214-4609-pdb.151.iptc14070 ◽

2009 ◽

Author(s):

M. Sohrabi ◽

M. Riazi ◽

M. Jamiolahmady ◽

S. Ireland ◽

C. Brown

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Co2 Storage ◽

Water Injection ◽

Carbonated Water Injection ◽

Carbonated Water

Download Full-text

Mechanisms of Microscopic Displacement During Enhanced Oil Recovery in Mixed-Wet Rocks Revealed Using Direct Numerical Simulation

Transport in Porous Media ◽

10.1007/s11242-019-01336-5 ◽

2019 ◽

Vol 130 (3) ◽

pp. 731-749 ◽

Cited By ~ 3

Author(s):

Takashi Akai ◽

Amer M. Alhammadi ◽

Martin J. Blunt ◽

Branko Bijeljic

Keyword(s):

Numerical Simulation ◽

Enhanced Oil Recovery ◽

Oil Recovery ◽

Water Flooding ◽

Surfactant Flooding ◽

Displacement Efficiency ◽

Low Salinity ◽

Low Salinity Water ◽

Salinity Water ◽

The Impact

Abstract We demonstrate how to use numerical simulation models directly on micro-CT images to understand the impact of several enhanced oil recovery (EOR) methods on microscopic displacement efficiency. To describe the physics with high-fidelity, we calibrate the model to match a water-flooding experiment conducted on the same rock sample (Akai et al. in Transp Porous Media 127(2):393–414, 2019. 10.1007/s11242-018-1198-8). First we show comparisons of water-flooding processes between the experiment and simulation, focusing on the characteristics of remaining oil after water-flooding in a mixed-wet state. In both the experiment and simulation, oil is mainly present as thin oil layers confined to pore walls. Then, taking this calibrated simulation model as a base case, we examine the application of three EOR processes: low salinity water-flooding, surfactant flooding and polymer flooding. In low salinity water-flooding, the increase in oil recovery was caused by displacement of oil from the centers of pores without leaving oil layers behind. Surfactant flooding gave the best improvement in the recovery factor of 16% by reducing the amount of oil trapped by capillary forces. Polymer flooding indicated improvement in microscopic sweep efficiency at a higher capillary number, while it did not show an improvement at a low capillary number. Overall, this work quantifies the impact of different EOR processes on local displacement efficiency and establishes a workflow based on combining experiment and modeling to design optimal recovery processes.

Download Full-text

Enhanced Oil Recovery and CO2 Storage by Carbonated Water Injection

10.2523/iptc-14070-abstract ◽

2009 ◽

Cited By ~ 2

Author(s):

Mehran Sohrabi ◽

Masoud Riazi ◽

Mahmoud Jamiolahmady ◽

Shaun Ireland ◽

Christopher Brown

Keyword(s):

Enhanced Oil Recovery ◽

Oil Recovery ◽

Co2 Storage ◽

Water Injection ◽

Carbonated Water Injection ◽

Carbonated Water

Download Full-text

Low-salinity carbonated water injection in sandstone reservoirs: interplay between oil recovery improvement, salinity and fines migration

The APPEA Journal ◽

10.1071/aj20079 ◽

2021 ◽

Vol 61 (2) ◽

pp. 575

Author(s):

Ehsan Yazdani Sadati ◽

Arman Siahvashi ◽

Suzanne Hurter

Keyword(s):

Oil Recovery ◽

Water Injection ◽

Water Flooding ◽

Fines Migration ◽

Recovery Method ◽

Low Salinity ◽

Salinity Reduction ◽

Carbonated Water Injection ◽

Carbonated Water ◽

Sandstone Reservoirs

Carbonated water injection (CWI) is described as a chemical-enhanced oil recovery method in which CO2-enriched water is injected into oil reservoirs as a displacing fluid. Although confirmed by many that a considerable amount of recovery improvement is attainable through CWI in both lab and field scales, the interaction of salinity on the performance of CWI and its potential fines migration is not very well understood. This study examines the efficiency of oil recovery improvement during low-salinity carbonated water injection (LSCWI) in a sandstone reservoir, while total dissolved salt concentration varies. To this end, a series of coreflooding experiments were performed on homogeneous sandstone cores at 80°C and 2000psi, and the amount of oil recovery was measured. From the experiments, it was observed that CWI could extract more crude oil than conventional water flooding in all salinities. In particular, the highest oil recovery was observed in the lowest salinity (61.2% in CWI and 42% during water flooding), indicating that by carbonating low-salinity water, oil recovery is enhanced by 20%. Moreover, the influence of salinity reduction on recovery enhancement was such that 9% of recovery improvement observed during conventional water flooding when salinity decreased from 40000 to 1000ppm. At the same time, this improvement was around 15% for CWI, suggesting that salinity reduction can be more effective in CWI rather than water flooding in recovery improvement. It was also found out that while recovery improvement and fines migration are both highly affected by water salinity, there is a synergy between the efficiency of CWI and onset of fines migration, which is one of the underlying mechanisms in oil recovery improvement during LSCWI into clay-containing sandstone reservoirs.

Download Full-text