In-situ microbial enhanced oil recovery (MEOR) is of high industrial importance during a period of low oil prices. However, in-situ MEOR is still not widely expanded due to the lack of sufficient data. This paper summarizes and analyzes the progress of in-situ MEOR in the Shengli oilfield. There are a variety of endogenous microorganisms in Shengli oil reservoirs. We assess the reservoir characteristics, activators, microbial community structure, and the correlation between predominant microorganisms and oil recovery increment in field trials of in-situ MEOR. The mechanisms of in-situ MEOR are acknowledged through field trials tests, long core flood experiments, and a visual microscopic seepage model. In-situ MEOR is shown to be an effective method for enhanced oil recovery. Future studies are needed to optimize the activator formula and control the combined effect of aerobic and anaerobic microorganisms.

As a potential therapeutic agent, the clinical application of S-nitrosoglutathione (GSNO) is limited because of its instability. Therefore, different formulations have been developed to protect GSNO from degradation, delivery and the release of GSNO at a physiological concentration in the active position. Due to the high water-solubility and small molecular-size of GSNO, the biggest challenges in the encapsulation step are low encapsulation efficiency and burst release. This review summarizes the different nano/micro-formulation strategies of a GSNO related delivery system to provide references for subsequent researchers interested in GSNO encapsulation.

Capacitive Deionization (CDI), a recently developed water treatment technology, has proved to be superior to traditional desalinization processes such as reverse osmosis (RO) in terms of high environmental friendliness, simple operation, and low energy consumption. This paper reviews the progress of research into CDI technology with focus on electrode materials and factors affecting CDI such as voltage and plate spacing. It also discusses existing problems and predicts the future development direction of this technology.

The rheology of a partially hydrolyzed polyacrylamide (HPAM) solution plays an important role in its oil recovery during polymer flooding. However, multiple factors in brine, such as sulfide ions, cause a dramatic loss in the viscosity and oil recovery. To better understand the sulfide-induced viscosity loss and the consequent flow mechanisms in pore networks, the morphology of polymer solutions with and without sulfide ion was observed by scanning electron microscopy; and the variations of the pore scale flow fields were demonstrated by a microscopic visualization seepage experiment combined with Micro-PIV (Microscale Particle Image Velocimetry). The results showed that, with the presence of sulfide ion, the microstructure of the polymer changed from a uniform three-dimensional network structure to loose and uneven floccules, which resulted in viscosity loss (over 70% with 5-mg/L sulfide ion). Moreover, higher concentrations of sulfide ions (5 mg/L and 10 mg/L) resulted in earlier shear thinning characteristics than those with lower sulfide concentrations. Due to viscosity loss, the average flow velocity in the main stream of the microscopic seepage experiment increased more significantly than that without sulfide. However, the viscosity loss alone cannot independently explain the severe viscous fingering during the subsequent post-water flooding, which was about five times greater than that of the primary water flooding in terms of the velocity ratio between the mainstream and margin. A further pore-scale flow field analysis exhibited an eccentric and a bimodal velocity distribution in the throat along the radial and axial directions, respectively. The former distribution indicated that the adsorbed polymer on the pore wall was broken through by hydraulic shear due to the collapsed structure caused by sulfide ion. The latter suggested that another sulfide-induced impact was an earlier-occurring non-Newtonian characteristic with a low shear rate. Therefore, instead of viscosity loss, elastic loss is the dominant mechanism affecting the characteristics of the aggregate flow field under the action of sulfide. Microscopic flooding combined with Micro-PIV is a feasible and essential method to reveal pore scale flow mechanisms.