Water Ion Interactions at Crude Oil-Water Interface: A New Fundamental Understanding on SmartWater Flood

2017 ◽  
Author(s):  
Subhash C. Ayirala ◽  
Ali A. AlYousef ◽  
Zuoli Li ◽  
Zhenghe Xu
Keyword(s):  
Crude Oil ◽  
Water Interface ◽  
Ion Interactions ◽  
Fundamental Understanding ◽  
Oil Water

Water Ion Interactions at Crude-Oil/Water Interface and Their Implications for Smart Waterflooding in Carbonates

SPE Journal ◽  
2018 ◽  
Vol 23 (05) ◽  
pp. 1817-1832 ◽  
Author(s):  
Subhash C. Ayirala ◽  
Ali A. Al-Yousef ◽  
Zuoli Li ◽  
Zhenghe Xu
Keyword(s):  
Crude Oil ◽  
Oil Recovery ◽  
Measurement Techniques ◽  
Fluid Interfaces ◽  
Water Interface ◽  
Oil Droplets ◽  
Coalescence Time ◽  
Ion Interactions ◽  
Phase Connectivity ◽  
Oil Water

Summary Smart waterflooding (SWF) through tailoring of injection-water salinity and ionic composition is receiving favorable attention in the industry for both improved and enhanced oil recovery (EOR) in carbonate reservoirs. Surface/intermolecular forces, thin-film dynamics, and capillary/adhesion forces at rock/fluid interfaces govern crude-oil liberation from pores. On the other hand, stability and rigidity of oil/water interfaces control the destabilization of interfacial film to promote coalescence between released oil droplets and to improve the oil-phase connectivity. As a result, the dynamics of oil recovery in smart waterflood is caused by the combined effect of favorable interactions occurring at both oil/brine and oil/brine/rock interfaces across the thin film. Most of the laboratory studies reported so far have been focused on only studying the interactions at rock/fluid interfaces. However, the other important aspect of characterizing water ion interactions at the crude oil/water interface and their impact on film stability and oil-droplet coalescence remains largely unexplored. A detailed experimental investigation was conducted to understand the effects of different water ions at the crude-oil/water interface by using several instruments such as Langmuir trough, interfacial shear rheometer, Attension tensiometer, and coalescence time-measurement apparatus. The reservoir crude oil and four different water recipes with varying salinities and individual ion concentrations were used. Interfacial tension (IFT), interface pressures, compression energy, interfacial viscous and elastic moduli, oil-droplet crumpling ratio, and coalescence time between crude-oil droplets are the major experimental data measured. The IFTs are found to be the largest for deionized (DI) water, followed by the 10-times-reduced-salinity seawater and 10-times-reduced-salinity seawater enriched with sulfates. Interfacial pressures gradually increased with compressing surface area for all the brines and DI water. The compression energy (integration of interfacial pressure over the surface-area change) is the highest for DI water, followed by the lower-salinity brine containing sulfate ions, indicating rigid interfaces. The transition times of interfacial layer to become elastic-dominant from viscous-dominant structures are found to be much shorter for brines enriched with sulfates, once again confirming the rigidity of interface. The crumpling ratios (oil drop wrinkles when contracted) are also higher with the two recipes of DI water and sulfates-only brine to indicate the same trend and to confirm elastic rigid skin at the interface. The coalescence time between oil droplets was the least in brines containing sufficient amounts of magnesium and calcium ions, while the highest in DI water and sulfate-rich brine, respectively. These results, therefore, showed a good correlation of coalescence times with the rigidity of oil/water interface, as interpreted from different measurement techniques. This study, thereby, integrates consistent results obtained from different measurement techniques at the crude-oil/water interface to demonstrate the importance of both salinity and certain ions, such as magnesium and calcium, on crude-oil-droplets coalescence, and to improve oil-phase connectivity in smart waterflood.

Study and Evaluation of Changqing Crude Oil Antiwaxing Agent

2019 ◽  
Vol 953 ◽  
pp. 166-171 ◽  
Author(s):  
Qing Mei Luo ◽  
Jian Yang ◽  
Li Jun She ◽  
Wen Jie Wan ◽  
Yun Ma ◽  
...  
Keyword(s):  
Crude Oil ◽  
Removal Rate ◽  
Salt Content ◽  
Water Interface ◽  
Wax Deposition ◽  
Wetting Ability ◽  
Deposit Surface ◽  
Low Salt ◽  
Oil Water ◽  
Wax Removal

In order to solve the problems of wax deposit, this study evaluated the effect of wax cleaning agent used in Changqing and adjusted its formulation. The results showed that the wax removal rate of oil based dewaxing agent was slightly higher than that of emulsion dewaxing agent for crude oil with low salt content. It is possible that the emulsion dewaxing agent contains a certain amount of mutual solvents, which improves its wetting ability at the oil-water interface and makes the oil and water dissolve each other. So that the wax deposit surface from hydrophilic hydrophobic to hydrophilic hydrophobic, forming anti-wax film to prevent wax deposition. Therefore, the wax removal ability of 1#, 3# oil wax is higher than that of oil base wax dewaxing agent.

Effect of Rheology Properties of Oil/Water Interface on Demulsification of Crude Oil Emulsions

2015 ◽  
Vol 54 (17) ◽  
pp. 4851-4860 ◽  
Author(s):  
Jun Tao ◽  
Peng Shi ◽  
Shenwen Fang ◽  
Keyi Li ◽  
Heng Zhang ◽  
...  
Keyword(s):  
Crude Oil ◽  
Water Interface ◽  
Oil Water ◽  
Oil Emulsions

Further Investigations into the Nature of Salt Spheres and Inorganic Structures at the Crude Oil−Water Interface†

2010 ◽  
Vol 24 (4) ◽  
pp. 2376-2382 ◽  
Author(s):  
Richard W. Cloud ◽  
Samuel C. Marsh ◽  
Sandra Linares-Samaniego ◽  
Michael K. Poindexter
Keyword(s):  
Crude Oil ◽  
Water Interface ◽  
Oil Water
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