Physical-Rheological Properties and Performances of Rejuvenated(Styrene-Butadiene-Styrene)Asphalt with Polymerized-MDI and Aromatic Oil

Traditional asphalt rejuvenators,like aromatic oil(AO),are known to be effective in improving the low-temperature properties and fatigue performances of aged SBS(styrene-butadiene-styrene)modified asphalt(SBSMA)binders and mixtures.However,these rejuvenators inevitably compromise their high-temperature properties and deformation resistances because they dilute asphalt binder but do not fix the damaged structures of aged SBS.In this study,a highly-active chemical called polymerized 4,4-diphenylmethane diisocyanate(PMDI)was used to assist the traditional AO asphalt rejuvenator.The physical and rheological characteristics of rejuvenated SBSMA binders and the moisture-induced damage and rut deformation performances of corresponding mixtures were comparatively evaluated.The results showed that the increasing proportion of AO compromises the hightemperature property and hardness of aged SBSMA binder,and an appropriate amount of PMDI works to compensate such losses;3%rejuvenator at mass ratio of AO:PMDI=70:30 can have a rejuvenated SBSMA binder with a high-temperature performance similar to that of fresh binder,approximately at 71.4°C;the use of AO can help reduce the viscosity of PMDI rejuvenated SBSMA binder for improving its workability;PMDI can help improve the resistance of AO rejuvenated SBSMA binder to deformation,especially at elevated temperatures,through its chemical reactions with aged SBS;moisture induction can enhance the resistance to damage of rejuvenated mixtures containing AO/PMDI or only PMDI;and the rejuvenator with a mass ratio of AO:PMDI=70:30 can lead the rejuvenated mixture to meet the application requirement,with a rut depth of only 2.973 mm,although more PMDI can result in a higher resistance of rejuvenated mixtures to high-temperature deformation.

Research on thermal insulation materials properties under HTHP conditions for deep oil and gas reservoir rock ITP-Coring

Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource assessments.The development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are key.Therefore,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation materials.The materials properties under coupled hightemperature and high-pressure(HTHP)conditions were tested.The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the process.High temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity.High temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the materials.The materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring device.Finally,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 MPa.To further improve the materials properties,the interface layer and EP matrix should be optimized.The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.

Petrophysical parameters inversion for heavy oil reservoir based on a laboratory-calibrated frequency-variant rock-physics model

Heavy oil has high density and viscosity, and exhibits viscoelasticity. Gassmann's theory is not suitable for materials saturated with viscoelastic fluids. Directly applying such model leads to unreliable results for seismic inversion of heavy oil reservoir. To describe the viscoelastic behavior of heavy oil, we modeled the elastic properties of heavy oil with varying viscosity and frequency using the Cole-Cole-Maxwell (CCM) model. Then, we used a CCoherent Potential Approximation (CPA) instead of the Gassmann equations to account for the fluid effect, by extending the single-phase fluid condition to two-phase fluid (heavy oil and water) condition, so that partial saturation of heavy oil can be considered. This rock physics model establishes the relationship between the elastic modulus of reservoir rock and viscosity, frequency and saturation. The viscosity of the heavy oil and the elastic moduli and porosity of typical reservoir rock samples were measured in laboratory, which were used for calibration of the rock physics model. The well-calibrated frequency-variant CPA model was applied to the prediction of the P- and S-wave velocities in the seismic frequency range (1–100 Hz) and the inversion of petrophysical parameters for a heavy oil reservoir. The pre-stack inversion results of elastic parameters are improved compared with those results using the CPA model in the sonic logging frequency (∼10 kHz), or conventional rock physics model such as the Xu-Payne model. In addition, the inversion of the porosity of the reservoir was conducted with the simulated annealing method, and the result fits reasonably well with the logging curve and depicts the location of the heavy oil reservoir on the time slice. The application of the laboratory-calibrated CPA model provides better results with the velocity dispersion correction, suggesting the important role of accurate frequency dependent rock physics models in the seismic prediction of heavy oil reservoirs.

Effects of Crude Oil Contamination on Soil Physical and Chemical Properties in Momoge Wetland of China

Large oilfields are often coincidentally located in major river deltas and wetlands,and potentially damage the structure,function and ecosystem service values of wetlands during oil exploration.In the present study,the effects of crude oil contamination during oil exploration on soil physical and chemical properties were investigated in marshes of the Momoge National Nature Reserve in Jilin Province,China.The concentrations of total petroleum hydrocarbons in the marsh soil near the oil wells are significantly higher than those in the adjacent control marsh.Soil water contents in oil-contaminated marshes are negatively correlated with soil temperature and are significantly lower than those in the control area,especially in fall.Crude oil contamination significantly increases the soil pH up to8.0,and reduces available phosphorus concentrations in the soil.The concentrations of total organic carbon are significantly different among sampling sites.Therefore,crude oil contamination could potentially alkalinize marsh soils,adversely affect soil fertility and physical properties,and cause deterioration of the marshes in the Momoge National Nature Reserve.Phyto-remediation by planting Calamagrostis angustifolia has the potential to simultaneously restore and remediate the petroleum hydrocarbon-contaminated wetlands.Crude oil contamination affects the soil physical and chemical properties,so developing an effective restoration program in the Momoge wetland is neccesary.

Influence of Different Hydrocarbon Molecules on Physical Properties of Mineral Base Oils

Different kinds of base oils with different viscosity were analyzed in this paper, including eight mineral base oils, alkylnaphthalene and three synthetic PAO oils. The influence of different hydrocarbon molecules on physical properties of mineral base oils was investigated, such as density(d), kinematic viscosity(KV), viscosity index(VI), etc. Possible reasons for some inconsistent phenomena in data processing were also theoretically analyzed in detail. The refractive indexes(RI), d and molecular weight(M) decrease linearly with the increase of paraffinic content other than KV, which declines exponentially. There are no clear relationships between physical properties of base oils and naphthenic content while polycyclic alkanes show a strong correlation with M and KV. The influence of aromatics on physical properties of base oils is just the opposite of paraffin's. VI of the base oils with low aromatics content increases linearly as their paraffinic contents rise when their carbon numbers are approximately equal. However, base oils with high aromatics content follow an utterly different rule, in which VI declines dramatically linearly with the increase in polycyclic aromatic content, which is the essential reason why naphthenic base oils all have terrible viscosity-temperature characteristics while paraffinic base oils usually do not.

Dissociation of polar oil components in low salinity water and its impact on crude oil-brine interfacial interactions and physical properties

Despite many efforts into the study of fluids interaction in low salinity water flooding, they are not probing the basics of transport phenomena between the involved phases. This work is aimed to bring new understanding of fluid-fluid interaction during low salinity water flooding through a series of organized experiments in which a crude oil sample with known properties was kept in contact with different brine solutions of various ionic strengths. Measuring brine pH, conductivity and crude oil viscosity and density for a period of 45 days illustrates the strong effect of the contact time and ionic strength on the dissociation of polar components and physical properties of the crude oil and brine. Besides, the interfacial tension(IFT) measurements show that the interfacial interactions are affected by several competitive interfacial processes. By decreasing the ionic strength of the brine, the solubility of naphthenic acids in the aqueous solution increases, and hence,the conductivity and the pH of the aqueous phase decrease. To verify this important finding, UV-Vis spectroscopy and 'H NMR analysis were also performed on aged brine samples. Notably, there is an ionic strength of brine in which the lowest IFT is observed, while the other physical properties are remained relatively unchanged.

Selected physical and chemical properties of mechanically extracted neem seed oil sourced as a preservative for ligno-cellulose in south-western Nigeria

Most of the seeds produced by neem （Azadirachta indica A. Juss） trees in Nigeria are currently underutilized. Hence, relevant literature provides only limited information conceming many of the seed oils from this country, especially where it concems the potential applications of these oils as preservatives for ligno-cellulose against bio-deterioration. Using standard procedures therefore, this study was carried out to evaluate and document selected physical and chemical properties of neem seed oil （NSO）, mechanically extracted using a cold press at 31.03 N-mm^-2 pressure and a room temperature of 25 ± 2℃. The results show that oil yield was 38.42% with a specific gravity of 0.91 ± 0.01. The amount of acid was 18.24 ± 1.31 mg KOH.g^-1 and that of iodine 93.12 ± 2.01 g-100 g^- 1, while saponification and peroxide values were 172.88 ± 2.06 and 1.42 ± 0.04 mg·g^-1 respectively. The implication of the values obtained, particularly those for the chemical properties, as they concern the potential application of NSO as a preservative for ligno-eellulose, is likely that it may be useful in this regard since the values may support some of the documented anti-microbial properties of the oil, although other physical and chemical properties that may affect this potential are recommended for investigations. Conclusions and other recommendations follow in line with the results of the study.

Study on Influencing Factors of Farmland Soil Heavy Metals in Central Yunnan Province

[Objective] This study aimed to explore the relationship between contents of heavy metals with soil type, altitude distribution as well as physical and chemical properties. [Method] Based on determination of contents of soil heavy metals and soil physical and chemical properties from agricultural land in Central Yunnan Province, the relationship between soil heavy metals with soil type, altitude distribu- tion and soil physical and chemical properties were analyzed. [Result] The average contents of all heavy metals in farmland of Central Yunnan didn＇t extend their limits of Grade II in the National Soil Environmental Quality Standard （GB15618-1995）. and the heavy metals content in red soil was higher than that in other types. Soil Cd content changes slightly with the altitude, while contents of other heavy metals were greatly affected by altitude. There were extremely significant positive correlation between heavy metals and clay particle content, that is, soil with heavier texture has more heavy metals. There was positive correlation between pH and each heavy metal content; there were positive correlation between Mn with Pb, Cd, Hg and Hg; exchangeable Ca and Mg contents in soil show negative correlations with most heavy metals. [Conclusion] This study has provided scientific bases for the heavy metal management in Central Yunnan area.

Viscosity profile prediction of a heavy crude oil during lifting in two deep artesian wells

It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.

CO2 assisted steam flooding in late steam flooding in heavy oil reservoirs

To improve the oil recovery and economic efficiency in heavy oil reservoirs in late steam flooding,taking J6 Block of Xinjiang Oilfield as the research object,3D physical modeling experiments of steam flooding,CO2-foam assisted steam flooding,and CO2 assisted steam flooding under different perforation conditions are conducted,and CO2-assisted steam flooding is proposed for reservoirs in the late stage of steam flooding.The experimental results show that after adjusting the perforation in late steam flooding,the CO2 assisted steam flooding formed a lateral expansion of the steam chamber in the middle and lower parts of the injection well and a development mode for the production of overriding gravity oil drainage in the top chamber of the production well;high temperature water,oil,and CO2 formed stable low-viscosity quasi-single-phase emulsified fluid;and CO2 acted as a thermal insulation in the steam chamber at the top,reduced the steam partial pressure inside the steam chamber,and effectively improved the heat efficiency of injected steam.Based on the three-dimensional physical experiments and the developed situation of the J6 block in Xinjiang Oilfield,the CO2 assisted steam flooding for the J6 block was designed.The application showed that the CO2 assisted steam flooding made the oil vapor ratio increase from 0.12 to 0.16 by 34.0%,the oil recovery increase from 16.1%to 21.5%,and the final oil recovery goes up to 66.5%compared to steam flooding after perforation adjustment.

Cameroon Green Energy Potentials: Field Survey of Production, Physico-Chemical Analyses of Palm Kernel Oil for Industrial Applications

This paper reports a field survey undertaken to determine the availability of raw material for palm kernel oil commercial production for industrial applications. Both industrial and artisanal wastes from palm kernel oil production were also surveyed as raw material (palm kernel seeds) for green energy production. Results of the field study show that 22% of palm kernel seeds (which represents tons of waste) resulting from palm oil processing plants are dumped while at the artisanal level, 80% of palm kernel seed waste is dumped. Analysis of field study data shows that large amounts of waste palm kernel seeds are available to enable large scale production of palm kernel oil (PKO) for desirable industrial applications in green energy production. The paper also reports on the physical and chemical properties of Cameroon palm kernel oil (PKO). Palm kernel oil was extracted using mechanical press and solvent extraction. The palm kernel oil (PKO) from Cameroon was analyzed by standard physico-chemical methods. Results of the physical measurements show a specific gravity of PKO of 0.92 kg/L, viscosity of 26.03 cSt and at 5.93 cSt at 40°C and 100°C respectively, viscosity index of 185, pour point of 20°C, cloud point of 29°C, flash point of 200°C, aniline point of 105°F, diesel index of 23, cetane number of 27 and ASTM (American Standards for Testing and Materials) color of less than 2.5. Results of chemical analyses showed an acid value of 17.95 mg KOH/g, free fatty acid (FFA) content of 8.98 mg KOH/g, iodine value of 2.10 mg I2/g, peroxide value of 2.10 meq/kg, ester value of 123.0 mg KOH/g, hydroxyl value of 93.4 mg OH/g, saponification value of 140.95 mg KOH/g and a sulfur content of 0.016% w/v, signifying low sulfur content. Gas chromatography-mass spectrometry (GC-MS) showed the palm kernel oil to be predominantly made up of glycerides of various fatty acids with higher proportions of C12 to C16 fatty acid residues. Cameroon PKO therefore has a broad spectrum of industrial applications by virtue of its rich physical and chemical properties.

Improvement of Used Transformer Oils with Activated Bentonite

This research presents the evaluation of activated Bentonite material for treatment of used transformer oil. Different properties such as;electrical, physical, chemical and thermal of used transformer oil were meas-ured before and after purification and treatment. Two power transformers were used in this research (6.4: 4.6 MVA, 3 phases, 50 Hz). One of them was filled with purified oil and the other was filled with activated Bentonite treated oil after purification, and then the two power transformers were tested for one year under practical conditions of the operating field. Initial tests have indicated that the use of Activated BENTONITE in the treatment process for the aged transformer oil improved breakdown voltage, water content, total acidi-ty and flash point. Thus activated Bentonite gives an ideal treatment of aged transformer oil with its environmental and economic advantages. Moreover, activated Bentonite is available at many places in Egypt with low costs.

Monitoring of steam chamber in steam-assisted gravity drainage based on the temperature sensitivity of oil sand

Thermosensitivity experiments and simulation calculations were conducted on typical oil sand core samples from Kinosis,Canada to predict the steam chamber development with time-lapse seismic data during the steam-assisted gravity drain-age(SAGD).Using an ultrasonic base made of polyether ether ketone resin instead of titanium alloy can improve the signal en-ergy and signal-to-noise ratio and get clear first arrival;with the rise of temperature,heavy oil changes from glass state(at-34.4℃),to quasi-solid state,and to liquid state(at 49.0℃)gradually;the quasi-solid heavy oil has significant frequency dis-persion.For the sand sample with high oil saturation,its elastic property depends mainly on the nature of the heavy oil,while for the sand sample with low oil saturation,the elastic property depends on the stiffness of the rock matrix.The elastic property of the oil sand is sensitive to temperature noticeably,when the temperature increases from 10℃ to 175℃,the oil sand samples decrease in compressional and shear wave velocities significantly.Based on the experimental data,the quantita-tive relationship between the compressional wave impedance of the oil sand and temperature was worked out,and the tem-perature variation of the steam chamber in the study area was predicted by time-lapse seismic inversion.

Temperature Dependence of Density,Viscosity,Thermal Conductivity and Heat Capacity of Vegetable Oils for Their Use as Biofuel in Internal Combustion Engines

This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Knowing vegetable oils’ physical properties to these ranges of temperature is of fundamental importance when modeling their combustion in diesel engine. However, vegetable oils’ experimental physical properties data are rare in the literature for temperature above 523 K. This paper describes experimental measurements and estimation methods for density, dynamic viscosity, thermal conductivity and heat capacity of vegetable oils for this particular range of temperature. The methodology uses several correlative methods using group contribution approach for each property and compares experimental data with predicted one to select the more accurate model. This work has shown the rapeseed and jatropha oils’ physical properties can be satisfactorily predicted as a function of temperature using group contribution approach.

稠油开采中多元热复合流体相态的研究进展

稠油的储量远超常规石油的储量,但因稠油黏度大和密度大的特点而难以开采,高效经济开发稠油已成为石油领域的研究重点。热复合开采技术是目前高效开发稠油油藏的关键技术,其中多元热复合流体的相态特征是稠油油藏开采流程设计与评价的关键。为此,从热复合开采技术中的混合气体系和稠油-气体系2个方面,系统地阐述了多元热复合流体相态的实验和理论研究现状。对于混合气体系相态,多采用静态法进行实验测试,使用状态方程结合混合规则进行理论预测,CO_(2),N_(2),H_(2)O和CH_(4)等常见气体分子组成的二元体系的相态测试趋于成熟,但缺少多元体系的测试数据与预测模型;对于稠油-气体系相态,总结了一般性实验流程与近年实验结果,提出一种加速油气相平衡的新型实验装置构想,指出目前理论预测在气体种类、注气量、气体扩散模型、二元相互作用系数等方面的不足。进而对多元热复合流体相态研究提出展望,以期促进热复合开采技术进一步的机理研究与参数优化。

不同提取工艺对鸡油理化性质与挥发性风味物质的影响

为了探究不同提取工艺对鸡油理化性质与挥发性风味物质的影响。本研究分别采用干法、湿法和微波熬制三种工艺提取鸡油,并对不同工艺提取鸡油的理化性质进行综合比较,同时采用顶空-气相色谱-质谱联用仪测定其挥发性风味物质构成,结合相对气味活度值、主成分分析和聚类分析明确不同提取工艺鸡油中的关键挥发性风味成分组成差异。结果表明,干法熬制的鸡油亮度最低,颜色更红、更黄,丙二醛含量较低;湿法熬制的鸡油亮度最高,颜色偏绿、偏黄,酸价较低;微波熬制的鸡油亮度稍暗,黄色和红色较浅,提取率较高,氧化稳定性较好且熬制时间短。不同提取工艺鸡油样品中共鉴定出49种挥发性风味物质,其中干法、湿法和微波法三种不同工艺所提取的鸡油中挥发性风味物质分别有39种、41种和44种,共有挥发性风味物质30种。结合ROAV和PCA,确定了(E,E)-2,4-庚二烯醛、1-辛烯-3-醇、己醛、(E)-2-癸烯醛、1-戊醇、辛醛、(E,E)-2,4-癸二烯醛、3-甲基丁醛为鸡油的主要特征风味物质。微波法提取鸡油的特征性风味物质含量较高且种类较多。本研究表明微波工艺相对而言具有耗时短、得率高、氧化稳定好以及鸡油特征性风味物质含量较高且种类多等优点,是一种值得深入研究与探索的鸡油提取工艺。

叠前流体指示因子反演在春光探区稠油层识别中的应用

春光探区东北部白垩系油藏类型主要为发育在不整合附近的稠油岩性油藏,常用的油气预测方法难以准确刻画油藏分布特征。为提高稠油层油气预测精度,形成了一种基于叠前流体指示因子反演的技术流程。首先对叠前地震资料进行优化处理,提高道集资料的信噪比和分辨率;然后在岩石物理分析的基础上,利用目标层流体性质与弹性属性的相关关系,构建流体指示因子属性;最后在叠前弹性参数反演的基础上,实现叠前流体指示因子反演,并根据稠油层特征优化反演参数,精细识别出稠油层的分布。该技术应用于春光探区东北部白垩系,预测结果与实钻井吻合度达到87.5%,取得了良好的应用效果。

页岩储层孔隙结构表征及物性下限确定方法及应用

针对页岩储层孔隙结构和物性下限认识不清,严重制约了页岩油储量计算及高效开发的问题,以济阳坳陷古近系沙河街组新义深9、利页1、樊页1井为研究对象,利用N_(2)吸附、高压压汞、物性测定等实验方法,对页岩储层的孔隙结构进行全尺寸表征,并综合运用束缚水饱和度法、压汞排驱压力法、最小流动孔喉半径法和试油法确定页岩储层的物性下限。研究表明:N_(2)吸附实验主要表征页岩样品的小孔,研究区孔隙形态主要有墨水瓶形、过渡形及平板状夹缝形,主要发育纳米级孔隙,孔隙半径为1.50~40.00 nm,平均孔隙半径为16.00 nm;高压压汞实验主要表征页岩样品的中孔和宏孔,孔喉半径为0.03~66.13μm;综合计算页岩储层孔隙度下限为1.30%~3.82%,渗透率下限为0.03~0.12 mD,最小流动孔喉半径为14.60~23.50 nm,平均值为17.76 nm。研究成果可为济阳坳陷页岩油的储量计算及储层评价提供参数指标和技术支撑。

透明砂土基本特性及其在注浆模型试验中的应用

透明土技术为可视化监测土体内部变形、渗流提供了有效手段,充分认识透明土透明度的影响因素是该技术发展的基础,亦是实现注浆模型试验浆液扩散可视化的前提。采用熔融石英颗粒和混合矿物油配制透明砂土,通过调整混合矿物油配比、熔融石英颗粒粒径、环境温度获得透明砂土。配制与标准砂级配相近的透明砂土,测试了透明土与标准砂的基本物理力学性能,并开展了大尺寸透明砂土注浆模型试验。结果表明:混合矿物油配比、熔融石英颗粒粒径对透明砂土透明度影响显著;混合矿物油折射率对温度较敏感,折射率随温度的升高而降低;与标准砂级配相近的透明土透明度较高,物理力学特性与标准砂相近,该透明砂土实现了注浆模型试验浆液扩散过程的可视化。研究成果对促进透明土技术发展及其在注浆模型试验中的应用具有借鉴意义。

辽河口湿地土壤有机碳组分特征及其影响因素

湿地生态系统碳汇潜力巨大,但不同的气候条件及植被类型,导致湿地土壤有机碳库组分有较大的差异,进而导致不同类型的湿地土壤有机碳受土壤理化性质的影响也有差异。深入了解土壤有机碳组分特征对滨海湿地生态系统开发及保护具有重要意义。以辽河口湿地为对象,选取5种土地覆盖类型(翅碱蓬群落、芦苇群落、光滩裸地、油井区和农耕区),分析不同土地覆盖类型下土壤有机碳组分及土壤基本理化性质,对所得数据进行相关性和差异性分析,以期探明辽河口湿地土壤有机碳组分特征,并确定土壤理化性质对辽河口湿地有机碳储量的影响。结果表明:辽河口湿地在不同土地利用类型下土壤总有机碳(Soil organic carbon,SOC)含量差异显著,其中芦苇群落碳储量最丰富,达(52.6±3.80) g·kg^(-1),光滩裸地碳储量最少,为(28.2±7.05) g·kg^(-1);在植物覆盖下土壤有充沛的碳输入而有利于土壤有机碳的固定,这一现象随土层深度的加深而减弱。轻组分有机碳(Light fraction organic carbon,LFOC)、重组分有机碳(Heavy fraction organic carbon,HFOC)和易氧化有机碳(Easily oxidized organic carbon,EOC)均与SOC含量具有显著的相关性(P<0.05),相关性大小为EOC>HFOC>LFOC。SOC含量与pH值、阳离子交换量呈显著正相关,而受含水率、总可溶性固体的影响不显著,这一现象可能与有机碳组分特征有关。辽河口湿地土壤碳库中HFOC占比最大,EOC占比最小,碳库结构较为稳定。pH值、阳离子交换量主要通过影响HFOC积累速率来影响SOC含量。因此,提高湿地土壤中较为稳定的HFOC储量,有助于提升湿地土壤的固碳能力。研究结果可为滨海湿地生态系统保护与碳汇功能提升提供参考。