Experimental investigation on the enhanced oil recovery efficiency of polymeric surfactant: Matching relationship with core and emulsification ability

The polymeric surfactant can be used as an efficient agent for enhanced oil recovery(EOR)because of its large bulk viscosity and good interfacial activity.However,there is a sparse understanding of its matching relationship with reservoirs and emulsification occurrence conditions,which may affect its migration and EOR efficiency.One intermolecular association molecule polymeric surfactant(IAM)was synthesized by micellar polymerization and characterized with 1 H NMR,FTIR,and TGA.The matching relationship between IAM and reservoirs was evaluated by comparing the viscosity retention rate of effluent in the core flow experiments.Moreover,the effect of the matching relationship on EOR in the heterogeneous reservoir was clarified with parallel core displacement experiments by considering different flow abilities of IAM in the high-permeability layer.The occurrence conditions of in-situ emulsification of IAM were evaluated via oil-water co-injection experiments under the different injection rates and oil-water ratios.Microscopic visualization displacement was carried out to compare the micro EOR mechanisms of different chemical systems.The results show that IAM features thickening,shearing resistance,viscoelasticity,thermal stability,and interfacial activity.The matching relationship between cores and IAM could be divided as hardly injected,flow limited,and flow smoothly,corresponding to the viscosity retention ratio of<20%,20%-80%,and>80%,respectively.IAM could gain better EOR efficiency(17.69%)when its matching relationship to the high permeability layer was“flow limited”.The defined mixture capillary number shows that only when it is greater than 1×10^(3),the in-situ emulsions can be generated.Compared to HPAM,IAM could reduce IFT and form vortices to more effectively displace film and corner remaining oils by stripping and peeling off crude oil.The formed emulsion accumulated at the pore throat could further increase flow resistance,which benefits swept area enlargement.This work could provide theoretical and data support for the parameters design in the polymeric surfactant practical application.

饲料熟化保持器产品概况与制标主要技术问题

目前饲料熟化保持器已经成为饲料加工中的重要设备,已在畜禽、水产、宠物饲料加工中体现出独特的优点和较好效益。文章介绍了国内外著名饲料机械公司生产的饲料熟化保持器产品的主要结构性能参数与特点,但目前国内外无该设备的国家和行业标准;同时提出了制定熟化保持器的标准需要进一步探讨的主要问题,包括产品名称、淀粉糊化度增加值、物料残留率、检修门尺寸、电加热热甲的安全性等。

Degradability evaluation for natural material fibre used on fish aggregation devices(FADs)in tuna purse seine fishery

Purse seiners deploy large amounts of drifting fish aggregation devices(FADs)in all tropical oceans to catch tunas.These FADs are constructed with porous synthetic fibre netting,which are responsible for incidental mortality of sea turtles and sharks through entanglement,and can engage in ghost fishing if they are lost and abandoned.The use of natural or biodegradable materials to build FADs can effectively mitigate marine pollution and bycatch issues,and as such they are currently promoted by fisheries management organizations.This study evaluated the degradability of ropes made of common natural fibres;cotton rope(3-strand,96-thread,twisted,S-lay),jute rope(3-strand,13-thread,twisted,Z-lay)and sisal rope(3-strand,8-thread,twisted,Z-lay).Degradability was evaluated by measuring the breaking strength(cN/dtex)and retention ratio of rupture elongation.Results showed that jute rope and sisal rope experienced rapid reduction of strength which over the first month soaking in the sea fell by 66.8%and 46.9%,respectively.Cotton rope exhibited the most inert degradation behavior,with breaking strength maintained at half of the initial value at 10 months.The retention ratio of rupture elongation for jute ropes and sisal ropes fluctuated considerably in the following months after deployment,compared to the relatively stable change for cotton rope.Results suggested that among these congeners,cotton rope would be most preferable component for Bio-FADs with a 10-month minimum durability that matches the required lifetime of FAD fishing strategies.

Three-dimensional computational fluid dynamics （volume of fluid） modelling coupled with a stochastic discrete phase model for the performance analysis of an invert trap experimentally validated using field sewer solids

Invert traps are used to trap sewer solids flowing into a sewer drainage system, The performance of the invert trap in an open rectangular channel was experimentally and numerically analysed using field sewer solids collected from a sewer drain. Experiments showed that the free water surface rises over the central opening （slot） of the invert trap, which reduces the velocity near the slot and allows more sediment to be trapped in comparison with the case for the fixed-lid model （assuming closed conduit flow with a shear-free top wall） used by earlier investigators. This phenomenon cannot be modelled using a closed conduit model as no extra space is provided for the fluctuation of the water surface, whereas this space is provided in the volume of fluid （VOF） model in the form of air space in ANSYS Fluent 14.0 software. Additionally, the zero atmospheric pressure at the free water surface cannot be modelled in a fixed-lid model. In the present study, experimental trap efflciencies of the invert trap using field sewer solids were fairly validated using a three-dimensional computational fluid dynamics model （VOF model） coupled with a stochastic discrete phase model. The flow field （i.e., velocities） predicted by the VOF model were compared with experimental velocities obtained employing particle image velocimetry. The water surface profile above the invert trap predicted by the VOF model was found to be in good agreement with the experimentally measured profile. The present study thus showed that the VOF model can be used with the stochastic discrete phase model to well predict the performance of invert traps.

Pre-treatment of pyridine wastewater by new cathodic–anodic-electrolysis packing

A novel cathodic–anodic-electrolysis packing（CAEP） used in the treatment of pyridine wastewater was researched, which mainly consisted of 4,4′-diamino-2,2′-disulfonic acid（DSD acid） industrial iron sludge. The physical properties and morphology of the packing were studied. The CAEP was used in a column reactor during the pretreatment of pyridine wastewater. The influence of p H, hydraulic retention time（HRT）, the air–liquid ratio（A/L）and the initial concentration of pyridine were investigated by measuring the removal of total organic carbon（TOC） and pyridine. The characterization results showed that the bulk density, grain density, water absorption percentage and specific surface area were 921 kg/m3,1086 kg/m3, 25% and 29.89 m^2/g, respectively; the removal of TOC and pyridine could reach50% and 58% at the optimal experimental conditions（p H = 3, HRT = 8 hr, A/L = 2）. Notably,the surface of the packing was renewed constantly during the running of the filter, and the handling capacity was stable after running for three months.