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1.
两相系统毛细压力-饱和度(h~S)关系曲线的确定是多孔介质多相流动研究的基础。采用简易试验装置对理想和实际介质中水-气和油-水两相系统中的h~S关系曲线进行了测定。试验结果表明,对于相同两相系统,多孔介质孔隙度愈小,同一毛细压力对应的饱和度相应愈大;对于不同两相系统,理想介质的关系曲线在一定毛细压力以下平缓,较大毛细压力时陡直,实际介质关系曲线走势相对较陡。分析结果表明,水-气和油-水两相系统的实测数据符合Parker等提出的基于van Genuchten(1980)关系式的折算理论;应用折算理论,可以在同一多孔介质某一两相系统h~S关系已知的情况下较好地估计同一孔隙度条件下其它两相系统的h~S关系曲线。 相似文献
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利用压力资料预测油（气）水界面方法的修正 总被引：2，自引：0，他引：2
文章在充分研究了原有压力法计算油(气)水界面海拔公式中存在的缺陷后,指出应引入含水饱和度参数对公式进行修正。修正后的公式所计算的油(气)水界面海拔值与实际值更接近,而且还能得出不同的含水饱和度界面海拔值。这由两个实际气藏的应用得到验证。 相似文献
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对于油田勘探和开发,特别是使用地震资料进行流体识别和预测,了解研究区地层孔隙流体性质及其影响因素十分重要.本文在前人研究工作的基础上,对油、气、水及其混合体的速度变化规律进行了讨论,并对影响油、气及水的速度因素进行深入分析.研究表明,不同性质孔隙流体受地层温度与压力的影响较大.其中,流体性质对纵波速度影响较大,而对横波速度影响较小;气-水混合体速度最低,油-水混合体速度最高,油-气或油-气-水混合体速度介于上述两者之间;混合流体含有气体时,含气饱和度对混合流体弹性性质具有很大影响. 相似文献
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为了提高空气扰动技术（air sparging,AS）的效果,做了一系列的实验,研究了表面活性剂强化空气扰动技术（surfactant-enhanced air sparging, SEAS）中表面活性剂的选择方法。结果表明：在气流运行方式以鼓泡为主要机制时,表面活性剂的加入强化了气泡的起泡性和稳泡性,使空气饱和度增加;在气流运行方式以微孔道为主要机制时,表面活性剂的加入因减小了表面张力而减小了空气驱替水所需的毛细压力,使空气饱和度增加。比较Tween-80、TritonX-100、SDS和SDBS在介质上的吸附损失,确定出在中砂中TritonX-100为优,在砾石中SDBS为优。 相似文献
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及时监测环境水中的镉含量是预防和治理镉污染的前提,采用分光光度法测定镉具有简便、迅速、易普及等特点,然而较低的灵敏度限制了该方法的应用。本文通过选用表面活性剂Triton X-114为增敏剂,有效地提高了镉试剂分光光度法测定镉离子的灵敏度。研究结果表明,在KOH溶液中,Triton X-114存在下,镉试剂与镉离子生成橙红色络合物,显色物质最大吸收峰为470 nm,镉离子含量在0~10 μg/25 mL范围内符合比尔定律,表观摩尔吸光系数达到1.25×105 L/(mol·cm),检测限低至5.0 μg/L。与Triton X-100以及其他表面活性剂相比,Triton X-114的应用能显著提高镉试剂光度法测定镉的吸光度,表观摩尔吸光系数最高可增加49%,检测限也能够降低近50%,并且分析方法简便迅速,易普及,可应用于环境水以及工业废水中微量或痕量镉的直接测定。 相似文献
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通过一维砂柱实验研究了阴离子表面活性剂十二烷基苯磺酸钠(SDBS)对空气扰动技术(air sparging,AS)修复氯苯污染地下水的强化效果.结果表明,SDBS的加入降低了地下水的表面张力,减小了水气两相毛细压力,从而提高了地下水中的空气饱和度.当曝气量为100 mL/min,地下水的表面张力由72.2 mN/m降至49.5 mN/m时,地下水中空气饱和度由13.2%提高至50.1%,而后随着表面张力的进一步降低,空气饱和度不再提高,反而有小幅下降.通过污染物的去除实验发现,SDBS的加入大大提高了氯苯的去除率,且去除率的变化与空气饱和度的变化趋势基本相符.因此,表面活性剂的加入可以作为空气扰动技术一种十分有效的强化手段. 相似文献
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两种膨润土的土-水特征曲线 总被引：2，自引：1，他引：1
用滤纸法和压力板法对Kunigel-V1和高庙子两种膨润土进行试验研究,量测不同孔隙比情况下的土-水特征曲线,研究土-水特征曲线与孔隙比之间的关系以及两种膨润土的土-水特性。试验结果表明：用吸力与含水率的关系表示土-水特征曲线时,在吸力较大的情况下,孔隙比对土-水特征曲线的影响不大;用吸力与饱和度的关系表示土-水特征曲线时,土-水特征曲线随着孔隙比的减小向右上方移动,即在吸力一定的情况下,饱和度随着孔隙比的减小而增加,并且此变化接近于线性变化。另外,孔隙比相同时,Kunigel-V1和高庙子膨润土的土-水特征曲线比较接近,即两种膨润土的持水特性比较相近 相似文献
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相对渗透率和饱和度定量关系是多孔介质多相流动系统中重要的动力学参数关系。使用设计的试验装置及试验方法测定了一维砂柱中油水两相动态流动系统的相对渗透率及饱和度数据,由试验结果分析表明:所测得的相对渗透率与实际情况吻合较好;细砂的强亲水性对不同先湿条件下的油、水相相对渗透率及饱和度有较大影响,并造成了不同先湿条件下流体间驱替机制的差异;相饱和度是影响相对渗透率的主要因素,孔隙空间中两种流体的分布方式和流体的饱和历史也影响各相相对渗透率。对试验结果用VGM模型(Parker-Lenhard模型)进行拟合所得结果较好;在水先湿条件下,将van公式拟合毛细压力-饱和度数据所得拟合参数用于VGM模型预测相对渗透率-饱和度曲线,所得结果与VGM模型直接拟合所得结果有差异,但两者所得结果均较好。 相似文献
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轻非水相液体（LNAPL）进入到地下环境中,首先在非饱和带进行垂向迁移,到达毛细带后在地下水面以上形成饱和透镜体。准确预测LNAPL渗漏在毛细带形成的透镜体厚度,对于LNAPL的去除及污染含水层的修复具有重要的指导意义。通过模拟实验测定了水-油两相吸湿及脱湿曲线,采用水-油饱和度-压力曲线拟合出了吸湿及脱湿进入压力。根据透镜体达到稳定状态时脱湿、吸湿压力水头之间的关系,建立了透镜体厚度的预测计算方法,并以中砂和粗砂为例,预测出实验条件下柴油在毛细带形成透镜体稳定时的厚度分别为4.61 cm和1.29 cm。通过室内模拟槽实验,测得柴油在中砂和粗砂中迁移时形成的透镜体厚度分别为5.30 cm和1.50 cm。预测与实验结果的相对误差分别为13.0%和14.0%。误差产生的主要原因为脱湿与吸湿曲线是在非干燥情况下测得,从而导致预测的透镜体厚度偏小。 相似文献
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Wimpy Karnanda M. S. Benzagouta Abdulrahman AlQuraishi M. M. Amro 《Arabian Journal of Geosciences》2013,6(9):3535-3544
In this research, effect of temperature, pressure, salinity, surfactant concentration, and surfactant type on interfacial tension (IFT) and critical micelle concentration of Saudi Arabian crude oil and various aqueous phases were investigated. The temperature ranged from ambient condition to 90°C, and the pressures were varied from atmospheric to 4,000 psi (27.58 MPa). Surfactant solutions were prepared using several aqueous phases, i.e., purified water, 10% brine consisting of 100% NaCl, 10% brine consisting of 95% NaCl and 5% CaCl2, and 10% brine consisting of 83% NaCl and 17% CaCl2. Out of 13 commercial surfactants, only three surfactants showed good solubility in pure water and brine. Those are Zonyl FSE Fluorosurfactant®, Triton X-100®, and Triton X-405®. Therefore, they were investigated thoroughly by measuring their efficiency in reducing the crude oil-aqueous phase IFT. Based on this screening process, laboratory surfactant flooding experiments for crude oil recovery were conducted using Triton X-405 and Triton X-100. The chemical flood was made at both original oil in place and at residual oil in place subsequent to conventional water flooding. Based on the obtained results, both surfactants were efficient, and more oil was recovered than that obtained through water flooding. Comparing both surfactant solutions, it was observed that Triton X-405 was more efficient than Triton X-100 at the same surfactant concentration and reservoir conditions. 相似文献
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Remediation with surfactant foam of PCP-contaminated soil 总被引：5，自引：0，他引：5
An investigation was made into evaluating the capability of surfactants in the form of foam for removing the contaminant pentachlorophenol (PCP), a highly toxic, wood preservative, from soil. Several surfactants were investigated for their ability to make foam. Two of them, Triton X-100 and JBR425 (a rhamnolipid biosurfactant), generated foam with higher quality (99%) and higher stability than other surfactants. Triton X-100 and JBR425 were then used to investigate the removal efficiency in soils contaminated with pentachlorophenol (PCP). Triton X-100 showed better results in terms of final removal efficiency. Triton X-100 (1%) removed 85% and 84% of PCP from fine sand soil and sandy-silt, respectively, contaminated with 1000 mg/kg PCP. These values were 60% and 61% for JBR425 (1%). Of this, 66% and 57% of the PCP was removed by volatilization by Triton X-100 and 36% and 44% by JBR425. Further experiments with Triton X-100 indicated that 1% Triton X-100 removed more than 0.5% and that PCP removal was approximately the same for 1% Triton X-100 for a higher contaminant level (3000 mg/kg) but more pore volumes of foam were required for fine sand (23 pore volumes compared to 12). For the sandy-silt soil, PCP removal was higher for the higher contaminant level, 84% compared to 76%. More pore volumes were required (35 compared to 21). Comparison of liquid and foam injection of 1% Triton X-100 indicated that the foam removed more than twice as much PCP in all cases than the liquid surfactant solution. The results of this study on a sandy and sandy-silt media, thus, found that the foam can be used as a fluid to enhance soil remediation under low pressures compared to other fluids such as liquid surfactant solutions. 相似文献
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考虑气相影响的降雨入渗过程分析研究 总被引：4，自引：1，他引：3
降雨入渗过程是水在下渗的过程中驱替空气的水-气二相流过程,对这一过程的精确模拟一直是渗流计算的难点,目前的处理方法通常是忽略孔隙气压力变化的影响。根据多相流理论,结合质量守恒定律和达西定律,建立了水-气二相流模型,模型的求解采用积分有限差分法和Newton-Raphson迭代方法,通过变换主要变量来表达相态的变化,实现了水相、气相边界条件及降雨入渗边界的精确模拟。利用上述模型对一土柱试验进行模拟,从而验证了模型的正确性,研究了一均质土层的降雨入渗过程,得到了孔隙水压力、孔隙气压力和毛细压力及含水率的变化过程。根据入渗率与地表孔隙气压力的变化关系,验证了孔隙气压力的增大对入渗水流产生阻滞作用。在求解非稳定渗流问题中,考虑空气压力变化的影响是值得研究的。 相似文献
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Triton X-100 (TX100) and Brij 35 (B35) were used to investigate the elevated critical micelle concentration (CMC) induced by surfactant sorption and its influence on PAH removal in soil washing systems. The surface tension technique was applied to determine the CMC and the apparent CMC (CMCsoil) in soil–water systems. Surfactant sorption experiments were conducted by the batch equilibration technique. Surfactants sorbed on the soil at concentrations below the CMCsoil were quantified with data from the surface tension experiments for both an aqueous system and a soil–water system. Due to sorption, the CMCsoil values of the two surfactants are 2.75 and 6.31 times their corresponding CMC values in aqueous solutions, respectively. At concentrations below CMCsoil, the loss of B35 (92–99.7 %) was greater than that of TX100 (63–92 %). The PAH removal efficiencies are greatly dependent on the CMCsoil value. At surfactant concentrations below CMCsoil, the PAH removal is very low and remains almost invariable. Whereas, at concentrations above CMCsoil, the PAH removal increases greatly. B35 inhibited PAH desorption at concentrations below its CMCsoil. For TX100, some degree of PAH desorption enhancement was observed at concentrations below its CMCsoil. CMCsoil is a key parameter while selecting a surfactant for a specific soil washing system, only surfactant concentrations above their CMCsoil should be evaluated. 相似文献
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毛管压力是影响煤层气赋存和开发的重要参数,为建立能够有效表征高阶煤煤岩毛管压力曲线的数学模型,以高阶煤为研究对象,开展了高压压汞实验,系统评价了目前常用的典型毛管压力曲线数学模型的适应性,建立拟合程度更高的数学模型。结果表明,6块高阶煤煤样毛管压力曲线基本没有中间平缓段,整体表现为向左上方凸出的形态,与常规砂岩、低阶煤差异明显;BC模型、贺承祖模型和Li模型均不能很好地拟合高阶煤的毛管压力曲线;建立的新毛管压力曲线数学模型,能够很好地拟合高煤阶煤样毛管压力实验数据,拟合程度达到97%以上;在双对数坐标中,毛管压力和最小毛管压力的对数差与进汞饱和度与最小毛管压力的对数差呈线性关系,可利用该线性关系直接求取毛管压力模型的斜率a和幂指数b,求解步骤较为简单;在其他条件相同时,毛管压力与斜率a和幂指数b均成反比。 相似文献
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This paper presents a numerical implementation of two-phase capillary hysteresis and its combination with a capillary interface
condition for the treatment of heterogeneities. The hysteresis concepts chosen in this work are first implemented in a node-centered
FV discretization scheme and subsequently combined with the interface condition that predicts sharp saturation discontinuities
at material interfaces, based on a pressure equilibrium concept. This approach allows for the approximation of history-dependent,
and at the same time discontinuous, saturations at material interfaces. The resulting model provides a well-defined evolution
of the hysteretic capillary pressure–saturation relationships at material interfaces that is independent of the grid spacing.
As demonstrated with a simple 1-D example, this concept therefore offers the advantage that the solution of a two-phase flow
problem involving hysteresis does not relate to the grid resolution at the material interfaces. 相似文献