A novel strengthened dispersed particle gel for enhanced oil recovery application

Caili Dai,Wenxia Chen,Qing You,Hong Wang,Yang Zhe,Long He,Baolei Jiao,Yining Wu 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.41 No.-

A novel strengthened dispersed particle gel (SDPG) was proposed and investigated to improve hightemperatureand high-salinity stability of foam, which uses silica nanoparticles as reinforcing material tosupport the inner framework of particle gel. In this paper, SDPG was successfully prepared and applied toa new three-phase foam system (STPFS). Indoor experiments were conducted to evaluate the salttolerance, thermal tolerance, plugging capacity and enhanced oil recovery capacity of the STPFS. It provedthat silica nanoparticles could improve the high-temperature and high-salinity stability of the gelparticles effectively. Consequently, the new three-phase foam system (STPFS) exhibited superior salt andtemperature resistance, with a salinity of 80,000 mg/L of Na+, 15,000 mg/L of Ca2+ and Mg2+ andtemperature tolerance of 110 C. In addition, core-flooding test indicated the STPFS possessed betterplugging capacity with a resistance factor of 310 and better enhanced oil recovery capacity with the oilrecovery increment of 26.79% under high temperature (110 C) and high salt environment (212,633.8 mg/L).

Synthesis, surface adsorption and micelle formation of a class of morpholinium gemini surfactants

Caili Dai,Sisi Fang,Mei Hu,Xiaojuan He,Mingwei Zhao,Xuepeng Wu,Shuai Yang,Yining Wua 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

A series of novel gemini surfactants with morpholinium headgroup, 4, 40-(alkane-4, n-40)bis(4-decyl, dodecyl or tetradecyl morpholinium)bromide (Mm-n-Mm, m = 10, 12, 14, n = 3, 4), were synthesized and characterized using 1H NMR. The surfactants were investigated for their adsorption and micellization in aqueous solutions through surface tension and conductivity methods It was found that the physicochemical properties, such as surface activity and thermodynamic property of the aqueous surfactant system, were dependent on the lengths of both hydrophobic tail chain and spacer. With the increase of the hydrophobic chain length or the decrease of spacer length, the cmc value of the surfactant decreases and the ability to reduce the surface tension is stronger. The calculation result of thermodynamic parameters indicated that the surfactants we synthesized are more inclined to aggregate in solution as compared with traditional m-s-m type gemini surfactants, and the micellization of Mm-n-Mm was an entropy-driven process.

New insights into the hydroquinone (HQ)–hexamethylenetetramine (HMTA) gel system for water shut-off treatment in high temperature reservoirs

Yifei Liu,Caili Dai,Kai Wangb,Mingwei Zhao,Guang Zhao,Shuai Yang,Zhihu Yan,Qing You 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.35 No.-

Aiming at water shut-off in high temperature reservoirs, the hydroquinone (HQ)–hexamethylenetetra-mine (HMTA) gel system was studied. The gelation performance and effects of various parameters weresystematically evaluated. With increase of the concentrations and temperature, gelation time decreasesand gel strength increases. In addition, gelation rate and gel strength were enhanced on adding acid. Moreover, the gel system shows good salt tolerance. The thermal stability measurement indicates thatthe gel can maintain stability up to 140 8C. Uniformly distributed three-dimensional network structurewas formed in the gel. At last, the gelation mechanism was proposed, illuminating the detailed gelationprocess clearly.

Development, formation mechanism and performance evaluation of a reusable viscoelastic surfactant fracturing fluid

Zhihu Yan,Caili Dai,Mingwei Zhao,Yongpeng Sun,Guang Zhao 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.37 No.-

Through extensive experiments, a reusable viscoelastic surfactant (rVES) fracturing fluid using a selfdesignedand synthesized surfactant was developed. Laboratory performance evaluation results showedthat various performances of rVES fracturing fluid are excellent. The most attractive aspect is the gellingand gel breaking of rVES fracturing fluid was achieved by altering the pH value. The recycled fracturingfluid still maintains good performances through three times cycles, which represents that it has goodprospects for re-use of flowback waters. In addition, large-scale coarse-grained molecular dynamics(CGMD) simulations results clearly revealed the formation mechanism of rVES fracturing fluid at themolecular level.

Investigation on bubble snap-off in 3-D pore-throat micro-structures

Yining Wu,Sisi Fang,Caili Dai,Yongpeng Sun,Jichao Fang,Yifei Liu,Long He 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

Bubble behaviors in the single and cascaded three-dimensional (3-D) pore-throat micromodels were studied at the operating ranging from 0.0007 to 0.0249. It was found that the average size of daughter bubbles decreased with the rising of the pore-throat ratio, length of throat and mother bubble velocity. The variation of the average size of daughter bubbles with capillary number could be scaled with a power law. In addition, the bubble breakup mainly occurred in the first pore-throat structure and the size of the daughter bubbles maintained almost stable.

CO2-responsive smart wormlike micelles based on monomer and “pseudo” gemini surfactant

Xuepeng Wu,Yongping Huang,Sisi Fang,Caili Dai,Hao Li,Zhongliang Xu,Mingwei Zhao 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.60 No.-

CO2-responsive wormlike micelles based on monomer erucic acid 3-(N,N-dimethylamino)propylamide (EADP) with or without sodium salicylate (NaSal) in aqueous solution were studied and compared with “pseudo” gemini system. The “pseudo” gemini system were formed by a mixture of EADP and maleic acid (MA) with molar ratio between 2:1–1:1. Different morphological transformations of microstructures in response to EADP concentrations, additives and CO2 stimuli were further investigated in these systems, the wormlike micelle or vesicles can be obtained. The mechanism of these transitions were further investigated by rheology, cryo-TEM and DFT calculation, the results showed that the mechanism behind this transition involved reversible reaction of CO2 with EADP. The mechanism in this research may give further evidence to the self-assembly of CO2-responsive surfactants.

Biomimetic functional hydrogel particles with enhanced adhesion characteristics for applications in fracture conformance control

Jiawei Liu,Lin Li,Zhongzheng Xu,Yongpeng Sun,Yining Wu,Caili Dai 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

Fracture conformance control in reservoir can effectively improve water channel to increase crude oil displacementefficiency of subsequent waterflooding. Inspired by the remarkable underwater wet adhesionof mussel byssus, hydrogel particles which can adhere stably on the fracture rock surface in reservoir conditionscould achieve long-lasting reservoir control effect. In this work, the size-controllable biomimeticfunctional hydrogel particles were prepared by mechanical shearing after bulk hydrogel was constructedby catechol-functionalized polyacrylamide and phenolic resin crosslinking agent. The influence of solutionsalinity on the aggregation and adhesion of hydrogel particles was investigated via scanning electronmicroscope (SEM), colloidal probe atomic force microscope (AFM) and quartz crystal microbalance withdissipation (QCM-D). The results showed that hydrogel particles maintained well-dispersed state in lowsalinitywater, while exhibited significant adhesion and adsorption capacity to the silica surface in simulatedreservoir salinity water. This is of great importance to the practical applications that the hydrogelparticles would not show enhanced adhesion to rock surfaces until the reservoir salinity water was met,which was beneficial to the in-depth migration of hydrogel particles to achieve effective deep reservoirprofile control. Furthermore, the visible micro-model was designed and applied to evaluate profile controleffect of hydrogel particles, and the results showed that hydrogel particles could withstand waterflushing and adhere stably to the fracture surface. The waterflooding sweep efficiency was increasedremarkably from 20.3% ± 2.0% to 38.8% ± 2.0%. This work would help better understand the functionmechanism of hydrogel particles in reservoir control and provide novel and efficient method for the practicalapplication in enhanced oil recovery.