Applied Sciences-Basel
·
2023
·Vol. 13
·期 9
·5248
·
IF 2.7
Hao Lai,Wei Shi,Junqi Wang,Lei Tang,Nanjun Lai
A low-permeability reservoir contains many fine pore throat structures, which result in excessive injection pressure of the water injection well and difficult water injection in the production process of a low-permeability reservoir. In this study, a new silane coupling agent was synthesized via the ring-opening reaction between dodecyl amine and KH-560 (γ-propyl trimethoxysilane). The modified KH-560 was reacted with nano-SiO2to synthesize the modified nano-SiO2as an antihypertensive additive. Fourier infrared spectroscopy, thermogravimetric analysis and laser scattering were used to characterize this modified nano-SiO2. The results show that the particle size of the modified nano-SiO2is less than 60 nm. The test results of the water contact angle show that the dispersion system can increase the rock contact angle from 37.34° to 136.36°, which makes the rock surface transform from hydrophilicity to hydrophobicity and reduce the binding effect of rock with water. The dispersion test shows that the modified nano-SiO2has good dispersion stability under alkaline conditions with TX-100 (Polyethylene glycol octylphenyl ether) as the dispersant. The antiswelling test results show that the antiswelling rate of this modified nano-SiO2is 42.9%, which can efficiently prevent the clay expansion in the formation to reduce the injection pressure. The core displacement test results show that its depressurization rate reaches 49%. The depressurization rate still maintains 46% at a 20 PV water flow rate, indicating that its depressurization effect is remarkable and it has excellent erosion resistance.Keywords:nano-SiO2;hydrophobicity;ultra-low-permeability reservoir;pressure reduction
研究领域:
石油工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Jinlong Cui,Kun Li,Liwei Cheng,Qingping Li,Zhenfeng Sun,Peng Xiao,Xingxun Li,Guangjin Chen,Changyu Sun
To improve the exploitation efficiency of future commercial marine natural gas hydrate , it is of critical significance to have a solid understanding of the spatial differences of hydrate dissociation. However, few studies have investigated this topic. In this study, a novel L-shape Hydrate Simulator (LHS) with a vertical vessel and a horizontal vessel was established and used to investigate the spatial differences of hydrate dissociation in water-saturated methane hydrate samples by depressurization. It was amazingly found that the hydrate dissociation was abnormally much faster in the location far from the mining well with the highest pressure than in the location near the mining well with the lowest pressure in the vertical vessel. This abnormal phenomenon was caused by the earliest uneven vacating of pore spaces in the vertical vessel. This phenomenon was not obvious in the horizontal vessel as there was little difference in the pore spaces vacating rates in different locations. The pressure reduction leaded to faster hydrate dissociation near the mining well in the horizontal vessel. The experiments on sediments with different permeability indicated that the sediments with higher permeability showed more pronounced spatial difference of hydrate dissociation, and the presence of clay (montmorillonite) in the sediments had significant impacts on the spatial difference of hydrate dissociation. The results in this study demonstrate that vacating of pore spaces of sediments is of determining significance for increasing hydrate dissociation rate in water-saturated sediments and provide important implications for developing methods to enhance the gas production from marine hydrate deposits.
研究领域:
海洋地质学
·
能源工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Shiwei Wang,Renling Lu,Gang Wang,Huarong Liu,Lu Lai
The mixing properties of amphiphilic carbon dots named C12-SCDs with a cationic surfactant (Dodecyl trimethyl ammonium bromide, DTAB) and an anionic surfactant (Sodium dodecyl sulfate, SDS) were investigated. Results indicated that surfactants DTAB and SDS show a synergistic effect in reducing surface tension with C12-SCDs. The synergistic effect of the DTAB/C12-SCDs mixture is more prominent than the SDS/C12-SCDs mixture, which may result from the electrostatic attraction between DTAB and C12-SCDs. Meanwhile, adding inorganic salts, the surface tension of these mixtures shows a trend of first decreasing slightly and then increasing. The DTAB/C12-SCDs mixture resists strong acids but not alkali environments. However, the surface tension of the SDS/C12-SCDs mixture gradually increases with the increase in pH. In addition, these mixtures have temperature-resistance properties. C12-SCDs and surfactants (DTAB and SDS) also have a synergistic effect in reducing the crude oil-water interfacial tension. Meanwhile, the DTAB/C12-SCDs and SDS/C12-SCDs mixtures have excellent wettability alternation performance. C12-SCDs and surfactants can form a mixed adsorption layer to promote the wettability alternation performance. The depressurization rates of DTAB, SDS, C12-SCDs, DTAB/ C12-SCDs mixture, and SDS/C12-SCDs mixture are 10.42 %, 11.54 %, 22.91 %, 26.32 %, and 24.75 %, respectively. The DTAB/C12-CDs and SDS/C12-CDs mixtures can effectively remove the oil film on the core surface, thus improving the channel of injected water. At the same time, these mixtures can be adsorbed on the surface of the hydrophilic core to form a hydrophobic surface , and the injection of water produces a hydrophobic slip effect. Finally, reducing the surface tension of water can also effectively reduce the injection pressure.
研究领域:
化学
·
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Zhen-Feng Sun,Shuai Jia,Qing Yuan,Chang-Yu Sun,Guang-Jin Chen
As a new kind of clean and high-energy resource, natural gas hydrate possesses promising prospects in exploitation and utilization. The characteristic of gas production in clay-rich sediments need to be further clarified for developing hydrates more safely and efficiently. To study the dissociation behaviors of methane hydrates in clayey sediments, a novel pressure retention system was applied to create both confined and unconfined environments using a one-dimensional visual hydrate simulator. Two types of methane hydrate deposits were simulated, of which were characterized by excess gas and excess water, respectively. Direct depressurization results showed that in confined environment, the increase of clay content in sediments will result in the decrease of gas phase permeability and gas production rate, but have negligible effect on the final gas recovery ratio. In unconfined environment, the infiltration of overlying seawater will result in the migration of fine-grained particles and extremely low gas recovery ratio. Moreover, the build-up of vertical pressure gradient was observed due to the occurrence of sediment compaction during depressurization process in clayey sediments. It is of significance to improve the effective permeability of the reservior and suppress water seepage for exploiting hydrate safely and efficiently.
研究领域:
地质学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF SUPERCRITICAL FLUIDS
·
2023
·
IF 3.9
Tianping Zhang,Shun Yao,Lu Wang,Weijun Zhen,Ling Zhao
Silicone rubber foam was prepared by direct rapid depressurization foaming process using supercritical CO 2 as foaming agent. It was found that under high temperature and pressure, the dissolution of CO 2 and the vulcanization reaction occurred simultaneously. The vulcanization degree range with good cell morphology was between 19.8% and 48.2%. When the saturation pressure exceeded 16 MPa, the cell morphology did not depend on foaming pressure. When the temperature was increased from 110 °C to 140 °C, the degree of vulcanization increased from 1.8% to 60.5%, and the cell size ranged from 13.9 µm to 646.4 µm, with an order of magnitude variation in cell density. This study identified the key control factors for supercritical CO 2 relief foaming of silicone rubber and provided a fast and efficient preparation method, as well as theoretical guidance, for obtaining lightweight microporous silicone rubber foams.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Gas Science and Engineering
·
2023
·
IF 0
Xian Sun,Xiao-Hui Wang,Peng Xiao,Yi-Fei Sun,Xing-Xun Li,Wei-Xin Pang,Qing-Ping Li,Chang-Yu Sun,Guang-Jin Chen
Hydrate reservoirs with underlying gas show significant potential for commercial exploitation. An experimental apparatus capable of applying confining pressure and axial pressure was built to simulate the accumulation and dissociation of naturally occurring marine hydrate and a novel method for synthesizing hydrate reservoirs with underlying gas was proposed. With the formed methane hydrate-bearing coarse sediment (HBCS) with underlying gas, hydrate dissociation experiments via depressurization under constrained conditions were carried out at different HBCS proportions. The characteristics of heat transfer and dual-gas co-production during the exploitation of hydrate reservoir at various HBCS proportions were presented. Due to the influence of hydrate decomposition, the diverging temperature variations of the underlying layer and upper HBCS layer were observed at HBCS proportions of 0.21, 0.48, and 0.77. The negative effect of the outside pressure on gas production was not observed in our experimental conditions owing to the adopted coarse quartz sand deposits. The final produced gas volume increases with the HBCS proportion increasing. The produced gas percentage is negative or positive related to the HBCS proportions respectively with the extended production time. In addition, the different production behavior of the underlying gas and hydrate decomposed gas may induce the unexpected exploitation accidents such as blowouts resulting from unstable gas production rate. These findings guide the design of exploitation scheme for reservoirs with different HBCS distribution. And an exploitation method by setting the production well in the underlying gas layer/underlying sediment layer with free gas is then proposed, which can inhibit hydrate reformation and ice generation and improve the production well stability during the hydrate exploitation process.
研究领域:
海洋地质学
·
能源工程
✓ 已验证
DOI
Journal of Neurogastroenterology and Motility
·
2016
·
IF 1.817
Hongfei Li,Ji-Hong Chen,Zixian Yang,Min Huang,Yuanjie Yu,Shiyun Tan,Hesheng Luo,Jan D Huizinga
Background/Aims Neurotensin is a gut-brain peptide with both inhibitory and excitatory actions on the colonic musculature; our objective was to understand the implications of this for motor patterns occurring in the intact colon of the rat. Methods The effects of neurotensin with concentrations ranging from 0.1–100 nM were studied in the intact rat colon in vitro, by investigating spatio-temporal maps created from video recordings of colonic motility before and after neurotensin. Results Low concentration of neurotensin (0.1–1 nM) inhibited propagating long distance contractions and rhythmic propagating motor complexes; in its place a slow propagating rhythmic segmental motor pattern developed. The neurotensin receptor 1 antagonist SR-48692 prevented the development of the segmental motor pattern. Higher concentrations of neurotensin (10 nM and 100 nM) were capable of restoring long distance contraction activity and inhibiting the segmental activity. The slow propagating segmental contraction showed a rhythmic contraction—relaxation cycle at the slow wave frequency originating from the interstitial cells of Cajal associated with the myenteric plexus pacemaker. High concentrations given without prior additions of low concentrations did not evoke the segmental motor pattern. These actions occurred when neurotensin was given in the bath solution or intraluminally. The segmental motor pattern evoked by neurotensin was inhibited by the neural conduction blocker lidocaine. Conclusions Neurotensin (0.1–1 nM) inhibits the dominant propulsive motor patterns of the colon and a distinct motor pattern of rhythmic slow propagating segmental contractions develops. This motor pattern has the hallmarks of haustral boundary contractions.
研究领域:
生理学
·
胃肠病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2025
·
IF 4.3
Shuaishuai Zhao,Li Liu,Zhihao Li,Xuliang Fan,Zhiqiang Wang,Mengyi Xing,Fushan Li
CO2 flooding is one of the paramount approaches to ameliorating the oil recovery rate of low-permeability reservoirs. Additionally, the physical and geological characteristics of low-permeability reservoir crude oil are less desirable owing to the influence of continental sedimentary structures. The minimum miscibility pressure (MMP) between CO2 and crude oil is generally higher than the formation fracture pressure, thereby rendering it difficult for CO2 to form miscibility with crude oil. Under such circumstances, a miscibility-reducing agent can be adopted to lower the miscibility pressure between CO2 and crude oil, thus achieving CO2 oil miscible phase flooding and elevating recovery efficiency. This paper first selected the most effective miscibility-reducing agent through molecular simulation experiments and core displacement experiments, and subsequently evaluated the injection effect of the miscibility-reducing agent on heightening the recovery rate of CO2 flooding in low-permeability reservoir cores. This research obtained the effect of the miscibility-reducing agents on the aggregation degree of CO2 molecules and asphaltene molecules during the oil gas mixing process from the radial distribution function and analyzed its function mechanism. On this basis, the core flooding experiment method was adopted to screen for the optimal miscibility-reducing agent with the best miscibility-reducing agent effect. Afterward, the impact of miscibility-reducing agent injection on the CO2 flooding development effect of the low-permeability core was evaluated systematically. As demonstrated by the molecular simulation results, selected miscibility-reducing agents displayed desirable electron transfer ability with CO2; Triisobutyl citrate can effectively heighten the aggregation degree of CO2 molecules and lessen the aggregation degree of asphaltene molecules, with the most conspicuous effect; The results of the core flooding experiment revealed that upon the injection of triisobutyl citrate, the MMP reduction between CO2 and crude oil exhibited the most remarkable trend, so it was selected as the best miscibility-reducing agent. The mechanism by which triisobutyl citrate can effectively reduce MMP mainly includes lowering crude oil viscosity and oil gas interfacial tension, and promoting the CO2 extraction ability. The indoor three-dimensional well network model CO2 flooding experiment results suggested that after injecting 0.07 PV of triisobutyl citrate preflush slug, the CO2 flooding recovery rate increased from 47.78% OOIP without the injection of miscibility-reducing agents to 59.86% OOIP. The selected triisobutyl citrate displayed a striking effect on augmenting the CO2 flooding recovery rate of low-permeability reservoirs. The research results provide a reference and inspiration for the high-quality and efficient development of CO2 flooding in low-permeability oil reservoirs.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 11
·7212-7221
·
IF 3.9
Jintang Wang,Zihua Shao,Yujing Bai,Guolei He,Xudong Wang,Lei Liu,Bo Liao,Xiaohui Sun,Kaihe Lv,Jinsheng Sun
The exploitation of natural gas hydrates (NGHs) by traditional methods is far lower than the commercial target. Calcium oxide (CaO)-based in situ supplemental heat combined with depressurization is a novel method for effectively exploiting NGHs. In this study, we propose an in situ supplemental heat method with the sustained-release CaO-loaded microcapsules coated with polysaccharide film. The modified CaO-loaded microcapsules were coated with polysaccharide films using covalent layer-by-layer self-assembly and wet modification process, with (3-aminopropyl) trimethoxysilane as the coupling agent and modified cellulose and chitosan as the shell materials. Microstructural characterization and elemental analysis of the microcapsules verified the change in the surface composition during the fabrication process. We found that the overall particle size distribution was within the range of 1–100 μm, corresponding to the particle size distribution in the reservoir. Furthermore, the sustained-release microcapsules exhibit controllable exothermic behavior. The decomposition rates of the NGHs under the effect of CaO and CaO-loaded microcapsules coated with one and three layers of polysaccharide films were 36.2, 17.7, and 11.1 mmol h−1, respectively, while the exothermic time values were 0.16, 1.18, and 6.68 h, respectively. Finally, we propose an application method based on sustained-release CaO-loaded microcapsules used for the supplemental heat-based exploitation of NGHs.
研究领域:
材料科学
·
化学工程
·
能源资源
·
环境科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 76
·61838-61845
·
IF 3.84
Caili Dai,Shilu Wang,Yuyang Li,Mingwei Gao,Yifei Liu,Yongpeng Sun,Mingwei Zhao
In this study, hydrophobic silica nanoparticles were prepared by the surface modification of silica nanoparticles using dimethyldichlorosilane. Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy were employed for the characterization of the raw silica nanoparticles and modified silica nanoparticles. The results showed that methyl groups are successfully grafted on the surface of silica nanoparticles. The titration method was employed to quantitatively determine the surface hydroxyl number of silica nanoparticles; the result demonstrated that the surface hydroxyl number of silica nanoparticles significantly decreases after modification. The modified silica nanoparticles was dispersed in water using TX-100 as the dispersant and NaOH to adjust the pH. The dispersion was injected into an oil-treated artificial core, the injecting pressure of the NaCl solution (5 wt%) before and after injection was measured. The result showed that the hydrophobic silica nanoparticles exhibit a good pressure-decreasing ability. The contact angle of the slabbed core was measured, the contact angle increased from 36° to 134° after it was treated by the modified silica nanoparticle dispersion. Transmission electron microscopy was employed for the characterization of the modified silica nanoparticles. Scanning electron microscopy was employed for the characterization of the treated core; the result showed that the modified silica nanoparticles are adsorbed on the surface of the core and forms a hydrophobic layer, changing the wettability of the sand surface from water wet to oil wet, thereby decreasing the flowing pressure.
研究领域:
材料科学
·
石油工程
·
界面化学
✓ 已验证
DOI
高影响因子
ENERGY
·
2024
·
IF 9
Jinlong Cui,Xiaohui Wang,Yalong Li,Zhenxi Wang,Guangjin Chen,Liwei Cheng,Sheng Xu,Meng Cao,Liwei Sun
Since the thickness of hydrate-bearing sediments is usually tens to hundreds of meters, the influence of gravity on hydrate dissociation characteristics can no longer be ignored. In this study, experimental simulations were designed to investigate the influences of gravity on hydrate dissociation characteristics by depressurization . The experimental results showed that for sealed water-rich marine hydrate reservoir, gravity could cause more water to migrate downward. The free pore space in sediments was thus rapidly vacated, resulting in faster hydrate dissociation and gas production. The average gas production rate increased from 0.018 mol/min to 0.038 mol/min. In addition, the free pore space at the top of the sediments was vacated first. Hydrate dissociation there was thus faster. For unsealed water-rich marine hydrate reservoir, gravity could not only cause more and faster migration of water, but also more easily cause the formation of dominant channels for water migration, leading to an effective reduction in reservoir pressure . The cumulative water yield increased from 1380g to 8950g. Hydrate thus dissociated. Hydrate dissociated faster at positions close to the mining well where the pressure was lower. These findings can provide deep insights into the spatial evolution of multiphase flows during the exploitation of natural gas hydrates .
研究领域:
地质学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
Food Production Processing and Nutrition
·
2024
·Vol. 6
·期 1
·1-12
·
IF 4
Du Jia,Xiao Miao,Sudo Naomi,Liu Qinghua
The homeostasis of the gut microbiota is a crucial factor in regulating peripheral and central blood pressure. Formulating a food-derived mixture of antioxidants, anti-inflammatory compounds and prebiotics to maintain the homeostasis of the gut microbiota will be essential for preventing and alleviating hypertension. Although bioactive peptides and plant extracts have been demonstrated not only to be excellent antioxidants and anti-inflammatory agents but also to promote the homeostasis of the microbiota, few studies have investigated the influence of multiple peptides mixed with plant extracts on the gut microbiota of hypertensive rats. This is the first study to characterize the fecal microbiome of spontaneously hypertensive rats supplemented with a mixture of multiple peptides and plant extracts by integrating 16 S rRNA gene sequencing. During the six-week experiment, the animals were healthy and without mortality. The results revealed that oral supplementation with the formulation reduced both systolic and diastolic blood pressure, improved the gut microbiota by increasing the ratio of Bacteroidetes to Firmicutes, and increased the relative abundance of specific genera, such as Lactobacillus. This study suggested that a synergistic formulation of multiple peptides mixed with plant extracts could be a novel strategy for preventing and alleviating hypertensive diseases. Graphical Abstract
研究领域:
营养学
·
微生物学
·
药理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）