Shuren Liu

Mechanism and Influencing Factors on the Initial Particle Size and Swelling Capability of Viscoelastic Microspheres

Viscoelastic microspheres are spherical particles with a three-dimensional network structure and have obvious swelling capability. The initial particle size and swelling ratio were introduced to study the effect of preparation conditions and external environmental factors systematically. The initial particle size could be controlled by adjusting the preparation conditions. The swelling capability was affected by both preparation condition and external environmental factor. The mechanisms of swelling are formation of hydrogen-bonded hydrolysis and diffusion induced by osmotic pressure. This work can provide some references for the particle size adjustment of viscoelastic microspheres in the profile control and flooding of heterogeneous reservoirs. GRAPHICAL ABSTRACT

Synthesis, Aggregation Behavior and Emulsification Characteristic of a Multi-sticker Amphiphilic Polymer

A multi-sticker amphiphilic polymer P(AM-NaA-DCHAM) was synthesized using micellar polymerization. Fluorescent spectroscopy, rheology and SEM were used to characterize the aggregation behavior of P(AM-NaA-DCHAM) solutions. Above CAC, aggregation formed by intermolecular association of hydrophobic groups can induce large quantities of hydrophobic microdomains and strong elastic polymer gel network structures in P(AM-NaA-DCHAM) solutions. O/W crude oil emulsions stabilized by P(AM-NaA-DCHAM) were prepared, and a laser particle size analyzer and Turbiscan lab stability analyzer were employed to study their stability. O/W crude oil emulsions stabilized by P(AM-NaA-DCHAM) get more stable as polymer concentration increases. The stability mechanism of O/W crude oil emulsions stabilized by P(AM-NaA-DCHAM) is probably because the elastic polymer gel structure of P(AM-NaA-DCHAM) in the continuous phase has the ability to hold oil droplets.

The relationships between rheological rules and cohesive energy of amphiphilic polymers with different hydrophobic groups

An amphiphilic polymer in water could form an aggregate due to its hydrophobic groups. The rheological properties of the three amphiphilic polymers’ solutions are different because of their different hydrophobic groups. By using a rheometer and a rotatory viscometer, the rheological properties and apparent viscosities of three kinds of amphiphilic polymers have been studied. The results show that all of the polymers are Newtonian fluids at a low shearing rate and pseudoplastic fluids at a high shearing rate. In addition, the amphiphilic polymer-P(AM/BHAM/NaA) has the best thickening behavior and the lowest value of critical aggregation concentration (CAC), which was also verified by fluorescence spectroscopy. By combining creep-recovery with cohesive energy calculation, the structural performance and interaction energy of the aggregate is the reason for the above mentioned phenomenon. By increasing the strength of hydrophobic groups, i.e., with an oil–water partition coefficient, then the structural viscoelasticity of the groups could be improved, and the associate is easily formed in the solution.

Study on Demulsification of a Demulsifier at Low Temperature and Its Field Application

The demulsification performance of a demulsifier at low temperature has been investigated. Bottle testing method was used to study the effect of water content, temperature, and demulsifier concentration on the demulsification performance. Interfacial rheological method was used to understand the demulsification mechanisms. Finally, a field test was carried out using the demulsifier in an oil-water treatment centre of Fuyu oilfield. It was found that this demulsifier has excellent demulsification performance when its concentration is about 100 mg/L and the demulsification temperature can be reduced by more than 15°C. This technology can be used to greatly reduce the energy consumption, and thus to reduce the production cost.

Bioremediation of Crude Oil Contaminated Soil

A laboratory study was undertaken to bioremediation crude oil contaminated soil by isolated strains. Pseudomonas strain A as the most superior indigenous biodegrader was selected. At the optimal growth condition of pH 7 and with 5 g/L NaCl, cosubstrate α-lactose, and inorganic salt FeSO4, 82.3% of crude oil degradation efficiency was obtained. Furthermore, characteristics of chemical composition during the biotreatment indicated that saturation hydrocarbons and some aromatics were effectively removed by strain A. N-alkane in crude oil was preferentially degraded, especially those in the range of nC16–nC24. Biodegradation of aromatics depended on benzene ring numbers and complexity of structures.

Adsorption of SDBS and Its Effect on Rheology of Preformed Particle Gels

The adsorption of anionic surfactant sodium dodecylbenzenesulfonate (SDBS) onto preformed particle gels (PPGs) and the effect of SDBS on the swelling ratio and rheology of PPGs were investigated. SDBS molecules can adsorb onto PPGs because of the hydrophobic association with the chain of PPGs at low concentration and the association of the SDBS micelles with the chains of PPGs at high concentration. PPGs contract and the shear stress of PPGs decreases after adsorption of SDBS. In addition, the storage modulus decreases first and then increases with increasing SDBS concentration.