Experimental investigation of smart carbonated water injection method in carbonates

Abstract

Enhanced oil recovery (EOR) has been noticed during recent years from reservoirs that are at the end of their life plateau or in which production has been declined. Two of these EOR methods are as follows: carbonated water and smart water injection. In carbonated water injection method, CO2‐contained water is injected in reservoirs in order to decrease free CO2 injection mobility, increase water viscosity, and store/remove produced greenhouse CO2 gas safely, and in smart water injection method, the ions in brine are modified in order to make controlled reactions with distributed ions on the surface of rock to cause more hydrocarbon recovery. In this paper, the combination of these two methods is investigated as hybrid smart carbonated water injection to find out the recovery factor change and effective mechanisms. Experimental core flooding setup is used for investigation of hybrid EOR injection applicability and mechanisms. Probable mechanisms are measured using different cores and five water samples are used for preparing carbonated water (at pressure of 2500 psi) including sea water (34 261 ppm), river water (1329 ppm), one of Iranian reservoir formation water (FW) (163 711 ppm), 10 times diluted FW (0.1 FW), and 100 times diluted FW (0.01 FW). The effect of both brine content and volume of CO2 is determined during hybrid EOR assessment. The main mechanisms activated including pH variation, oil swelling, oil viscosity reduction, ion concentration variation in brine and porous media, and wettability alteration have been investigated. Hybrid method resulted in highest recovery (70%) mainly due to ion exchange, wettability alteration, oil swelling, and permeability enhancement. In addition, type of salt concentration will affect recovery as 0.01 FW results in 8% and 16% additional oil recovery compared to sea and river waters, respectively. Coupling of CO2 and salts will increase recovery factor due to mechanisms activated by each of these factors as 0.01 FW results in 10% more oil recovery compared to FW. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

Enhanced Oil Recovery and CO2 Storage by Enhanced Carbonated Water Injection: A Mini-Review

“…Soleimani et al 55 investigated the impact of CLSW on recovery under dynamic coreflooding conditions with carbonate rocks. Studies have demonstrated that lower salinity levels in CLSW result in significant improvements in wettability, thereby increasing the oil recovery.…”

“…Moreover, at the reservoir scale, the injection capacity demonstrated a 31% improvement over CW injection. Soleiman et al prepared CW using formation water at various dilution levels, ranging from 1637 to 163711 ppm, and reached consistent conclusions. Furthermore, they found that the higher the salinity of the water, the lower the dissolved CO 2 in it.…”

“…The synergistic effect of combining surfactants with CW has been demonstrated in our prior core flooding experiments , and confirmed by other research. , The increased CO 2 solubility, reduced IFT, and improved wettability resulted in a final recovery of 40 to 64% from the active carbonated water (ACW) injection. ,,,, Karfry et al . demonstrated that CLSW improves wettability, increases CO 2 dissolution, and enhances core porosity and permeability through dissolution, similar to the experimental results of Soleiman et al With the synergistic effect of low salinity water and CW, the final recovery of CLSW injection reached 51 to 80.2%. The results of core flooding experiments by Bakhshi et al and numerical simulations by Lee et al suggest that CLSW can achieve improved CO 2 storage; however, some argue that the reduced salinity of CLSW may be detrimental to CO 2 storage.…”

Mechanistic study of the carbonated smart water in carbonate reservoirs

“…This mineral precipitation has been observed experimentally at the core scale for carbonate reservoirs. 4,47 However, no study has been reported for fractured reservoirs. The heterogeneity effect on mineral dissolution appears in this system, as shown in Fig.…”

Carbonated Water Injection for Enhanced Oil Recovery and CO2 Geosequestration in Different CO2 Repositories: A Review of Physicochemical Processes and Recent Advances

“…Specifically, CWI offers advantages such as better microscopic sweep efficiency, increased contact time between CW and trapped oil, elimination of gravity segregation, reduction of high water saturation and water shielding effects, and facilitation of CO 2 mass transfer between trapped oil ganglia and CW. , Other favorable aspects of CWI for EOR and CGS include the reduction in required CO 2 volumes, augmented brine injectivity, wettability alteration, swelling of trapped oil globules, delayed injected phase breakthrough, and lower risk of buoyancy-driven leakage . Several recent studies have confirmed that CWI outperforms CO 2 injection and CO 2 WAG regarding EOR and CO 2 storage performance. ,− Ajoma et al demonstrated both experimentally and simulation-wise that water-saturated CO 2 injection stored more CO 2 (3.8 megatons) than pure CO 2 injection (2.71 megatons). Furthermore, Soleimani et al also found that hybrid smart CWI outperformed other CO 2 injection scenarios regarding oil recovery.…”