The impacts of gas impurities on the minimum miscibility pressure of injected CO_2-rich gas–crude oil systems and enhanced oil recovery potential

An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO_2,which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO_2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen(N_2), methane(C_1), ethane(C_2) and propane(C_3) on CO_2 MMP. The simulation results reveal that,as an impurity, nitrogen increases CO_2–oil MMP more so than methane. On the other hand, increasing the propane(C_3)content can lead to a significant decrease in CO_2 MMP, whereas varying the concentrations of ethane(C_2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO_2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.

Impact of Crude Oil on Soil Nitrogen Dynamics and Uptake by Legumes Grown in Wetland Ultisol of the Niger Delta, Nigeria

The effects of crude oil on soil nitrogen dynamics and cycling in plant-soil ecosystems and its effect on the growth of legumes (Calopogonium mucunoides, Centrosema pubescens and Pueraria phaseolodes) grown in wetland ultisols were investigated. The test plants species were grown on wetland soil simulated with 0.35, 10.8, 20.5, and 50 g.kg-1levels of crude oil contamination. The results showed time and species dependent variation in mineral N content of the treated soils. The variation is indicative of significant interaction between the hydrocarbon content and plant species. Variations in microbial N and microbial C were similar and correlation between the microbial N and the total C (Organic matter (C) + hydrocarbon content (C)) in soil was highly significant (r = 0.96, n = 12, P ≤ 0.01). The presence of hydrocarbon contaminant widens the C:N ratio in soil and leads to more available N being immobilized by soil microorganisms, which reduces available N for plant uptake. This result implies that crude oil contamination significantly reduces N uptake by plants but increases N accumulation in soil microbial biomass. The findings show that N dynamics, transformation and cycling in soil are influenced by hydrocarbons and that the interactions between hydrocarbon content and plant species in contaminated soil are remarkable. The use of plant Centrosema pubescens with poultry manure or NPK fertilizer for bioremediation is more effective than that of Calopogonium mucunoides and Pueraria phaseoloides. However, the selective attributes of the various treatment approaches adopted here may be exploited for enhanced remediation of contaminated wetlands in the Niger Delta region of Nigeria.

Phytoremediation of Crude Oil Contaminated Soil with <i>Axonopus compressus</i>in the Niger Delta Region of Nigeria

The study assessed the effectiveness of carpet grass (Axonopus compressus) in the phytoremediation management of oil impacted soil in Ubeji and Alesa Eleme communities of Niger Delta region of Nigeria. To achieve this, the study employed an experimental research design that involved the use of Axonopus compressus in the management of oil-impacted soil sites of Ubeji and Alesa Eleme. This experiment lasted for four months’ period (one planting season). Axonopus sp. was used for the treatment of the crude oil impacted sites. Laboratory analysis of the soil samples was conducted to determine the effect of phytoremediation on hydrocarbon, acidity, organic matter and moisture loss in oil impacted sites. The study revealed that the use of Axonopus sp. resulted in 66% loss of hydrocarbon from crude oil-impacted soils of Ubeji and Alesa Eleme. However, there is no significant difference in crude oil loss in the soils of Ubeji and Alesa Eleme as a result of Axonopus sp. This could be ascribed to the similarities in soil properties and climate type of the Niger Delta region of Nigeria. It also showed that the growth of Axonopus sp. in the crude oil-impacted soils of Ubeji and Alesa Eleme has reduced the acidity of hydrocarbon content in soils (4.46 - 6.87 pH in Ubeji and 4.66 - 6.86 pH in Alesa Eleme) from the first day to the 90th days of experiment, and thereafter there was stabilization at the 4th month. This indicates that acidity in soil increases (lower pH) with increase in the concentration of crude oil in soils. However, the adoption of Axonopus sp. in hydrocarbon-impacted soils has increased the pH of soils, and enhanced the accumulation of organic matter and moisture content in oil-impacted soils of Ubeji and Alesa Eleme. The implication of the findings is that Axonopus sp. has the tenacity to phytoremediate hydrocarbon concentration in soil effectively in any geographical region of the world;as such, it is recommended for adoption by oil companies, government and non-governmental organization agency for the remediation of oil spill sites.

原油价格不确定性测度及其对宏观经济的非对称影响研究

有效测度原油价格不确定性并研究其对我国宏观经济的影响,具有重要的理论和现实意义。本文基于最小生成树模型,从全局视角衡量原油多元定价机制中195个影响因素的相对重要程度,并采用高维因子非预期条件波动率模型测度国际原油价格的不确定性。基于收敛交叉映射模型,本文对原油价格不确定性与宏观经济间的非线性因果关系进行识别,研究发现仅存在原油价格不确定性对固定资产投资、产出增速的单向因果关系。进一步地,在厘清原油价格不确定性对宏观经济影响机制的基础上,利用包含马尔可夫区制转移特征的向量自回归模型考察原油价格不确定性对我国宏观经济的影响,理论与实证结果均表明原油价格不确定性对我国宏观经济具有显著负向影响;在不同经济状态下,原油价格不确定性对投资、产出增速的影响具有非对称性。本研究为有效防范原油市场风险、保障能源安全和推动经济稳定增长提供了理论支持。

国际原油价格波动对我国外贸收支的冲击效应

本文以2001年1月至2012年12月外贸收支差额、国际原油价格、实际汇率、贸易条件和产出缺口等内生变量和加入WTO、金融危机两个外生变量的月度数据为样本,采用受限向量自回归(CVAR)模型,实证分析国际原油价格波动对我国外贸收支平衡的动态冲击效应。结果表明,油价冲击是造成我国外贸收支失衡的一个重要影响因素,其作用大于实际汇率、贸易条件和产出缺口。油价上涨将对外贸收支差额产生负向影响,但从长期看,新能源和替代能源的开发利用以及中国出口产品能源密集度的降低,将使油价变动对外贸收支失衡的影响逐渐消失。

大型开敞式原油码头船舶作业和系泊安全条件试验研究

为保障某大型开敞式原油码头船舶作业和系泊安全,采用整体物理模型,试验测量了不同风浪流组合作用下,系泊船舶的运动量、系缆力和撞击力,并分别以运动量和系缆力为衡量标准,分析得到不同风流条件下45万t和10万t油船作业和系泊的允许波高及周期。结果表明:油船纵、横移运动量最大允许值取2 m较为合适;我国现行规范对10万t油船允许作业波高及周期的规定时合适的,而单横浪作用下,45万t油船的允许作业波高则可提高至2.0 m,对应平均波周期为8 s。

管道沿线结蜡分布不均匀对蜡层厚度计算的影响

根据原油管道的结蜡规律,分析了蜡层分布不均匀对管道蜡层厚度计算的影响。在管道直径长度相同、沿程摩阻增加相同的条件下,随管道结蜡段长度的减少,有效平均结蜡厚度减小。根据站间压降反算得到的水力学平均蜡层厚度,并不能说明管道的实际结蜡情况。对于压降上升较快的管道,利用压降反算得到的蜡层厚度会夸大管道结蜡的严重程度,而忽视某些区段的潜在隐患。

双管同沟技术中的土壤温度场的计算

用数值模拟来研究冷成品油管对恒稳态热油管热量的传递问题,使用西部管道作为研究对象。在研究中,主要使用新疆北部的埋地管道和90#汽油。通过导热方程计算不同条件下的成品油管和原油管土壤温度场的变化情况。用三节点单元格对管道土壤进行模拟。根据模拟图得出结论。

中俄输油管道(漠河—乌尔其段)沿线冻土环境影响评价

中俄输油管道漠河—乌尔其段长约441km,南北向纵贯整个大兴安岭多年冻土区,该区处于欧亚大陆冻土区东南边缘,冻土总体厚度较薄、温度较高、稳定性较低,易受外界因素干扰。本文根据多年冻土的区域分布规律及分布的连续程度,并考虑地温、冻土厚度、植被变化等特征将管道沿线分成4个冻土亚区。在此基础上分析了多年冻土类别特征、多年冻土在地形地貌上的分布规律、冻土工程性质、地表植被、冷生现象等标识性指标之间的相互依存关系,提出了适应于中俄管道沿线多年冻土区的地表稳定型多年冻土环境评价方法。并利用此方法对沿线各个冻土亚区不同地表稳定型的冻土区段进行了统计分析。

超声清洗石油污染海滨土的效果与影响因素

土壤的石油类有机污染物污染是近几年继农药和重金属之后的又一大污染。石油主要是由烷烃、环烷烃和芳香烃组成的混合物,具有致癌、致畸、致突变的潜在性。常规技术净化酸性的落地油泥的效果并不理想,而声化学处理以前就被认为是修复碳氢化合物污染土的一个有效方法。基于此,本研究对石油污染的海滨土开展了以声化学为技术手段的修复实验。在本实验研究中,泥浆浓度、清洗时间、温度、泥浆pH值、投加碱性添加剂与微量自由基试剂H2O2等因素对石油烃从细粒海滨土中的解吸效果的影响得到考虑。根据实验结果,在采用声化学工艺净化海滨细粒土时,建议工艺操作参数控制在液固比6∶1、超声作用时间5 min、常温20℃、pH值9、Na2CO3的投加量为0.15%。另外,在处理过程中有必要采取措施及时避免清洗过程油泥造成的固结现象。

稠油乳化降黏剂研究进展

文章结合稠油乳化降黏剂的作用机理,综述了近年来复配型、抗矿盐型、耐高/低温型、共/缩聚物型和易脱水型等典型乳化降黏剂的研究现状,分析了影响乳状液稳定性和降黏率的因素,并结合近年来研究的焦点问题,提出了乳化降黏剂目前的发展方向。

TR-01稠油乳化降粘剂研究

针对河南油田井楼区块稠油,自制TR-01乳化降粘剂,通过实验研究了其降粘性能、稳定性,确定了降粘剂TR-01最佳浓度为0.3%、最佳油水比为70∶30。实验结果表明:TR-01乳化降粘剂对井楼区块油井的普遍适用性较强,具有较好的乳化降粘作用(降粘率达到99%以上),地层水对其降粘效果影响不大。其中的纳米成分能增加对污水中悬浮物的吸附能力和絮凝能力,对油田污水处理起到积极作用。

中国主要滨海油田分布区的生态环境特征及保护对策——以环渤海油田区为例

环渤海地区是我国滨海油田的主要分布区,同时也是典型的生态脆弱区。多年来高强度的石油开采严重破坏了当地生态环境,油田企业虽采取了许多环境治理措施,但生态环境并未出现好转的趋势。本文概述了我国环渤海地区的生态环境特征和油田开发历史,分析了油田开发对生态环境的影响,阐述了油田现行污染物的治理措施,提出了滨海油田区环境的综合治理对策,以资借鉴。

港口原油装船VOCs大气环境影响探讨

收集了原油装船VOCs的估算方法,认为原油装船时VOCs排放量为0.012%,VOCs浓度为0.1kg/m3。采用SCREEN3对其环境影响进行分了析,结果表明:下风向最大浓度出现在400m处,浓度值7.99mg/m3,直到2700m处,浓度值才小于1mg/m3,直到10000m处,浓度值仍为0.14mg/m3,原油装船VOCs的大气环境影响较大。

石油污染法和地面油罐的法规

译文叙述了地面和地下储油罐对环境影响的差异、美国环保局（EPA）对此的有关规定、石油污染法、全国污染物排除控制系统（NPDES）等。最后介绍地面油罐法规具体内容。

原油加工对催化裂化装置的影响

文章叙述了高钙原油中钙的分布及存在形式,加工高钙原油对催化裂化装置反应转化率、催化剂流化、烟机及余热锅炉的影响,并提出了加工高钙原油的改进措施。

基于有限元法的含蜡原油管道停输过程温降数值模拟

含蜡原油在管输过程中不可避免地会发生停输情况,随着管内原油温度降低至凝点以下,会出现凝油层导致凝管现象,严重影响管道安全经济运行,因此有必要研究含蜡原油管道停输过程的温降问题。在原油管道正常运行工况的基础上,考虑蜡沉积现象,建立了含蜡原油管道停输传热模型。采用温度场三角形单元格划分→离散→合成有限元这一有限元法求解思路对模型进行数值求解,讨论了在不同停输时间管道温降的变化规律。通过对管道温度场计算结果进行分析可知,管道对周围环境温度场的影响随着离管道距离的增大而逐渐减小;在不受热影响的外部区域,温度场等温线近似为一组波动的平行线。该研究成果提供了一种简单易行、准确可靠的温降模拟计算模型,为蜡质原油停输后再启动过程的方案制定提供了关键数据的采集方法。

某原油库泄漏油品流散数值模拟与分析

储罐发生油品泄漏事故后,由于油品流动性及不溶于水等特性会导致油品沿着地面或水面流淌扩散,不仅会增大火灾危险性,还会对环境造成严重的污染。研究储罐泄漏后的原油流散情况,对提高油库安全管理水平与制定应急处置预案具有重要指导意义。以不同容量储罐为研究对象,计算罐壁破裂后原油的泄漏速率。基于FLOW-3D软件,模拟研究单罐和双罐发生储罐破裂事故后泄漏原油的流散状态,分析原油的流散速度、原油对防火堤的冲击压力及原油的外溢量,直观立体地展示不同罐区泄漏原油的流散形态。最后,针对研究结果提出了提高原油储库安全管理水平的建议措施。

新型冠状病毒肺炎疫情对国际干散货航运市场的短期影响

为探究新型冠状病毒肺炎(Corona Virus Disease 2019,COVID-19,简称新冠肺炎)疫情对国际干散货航运市场的短期影响,应对新冠肺炎疫情下动荡的国际贸易,为干散货航运市场的发展提供方向与建议,考虑到国际原油价格在反映世界经济发展状况的同时,作为上游产业同干散货航运市场联系密切,选用回归分析法,结合国际原油价格考察新冠肺炎疫情对干散货航运市场的冲击并探究其冲击角度。结果表明,即期新冠肺炎疫情对干散货航运市场冲击显著,滞后1~7期新冠肺炎疫情同干散货航运市场均具有较强相关性,存在持续性冲击。新冠肺炎疫情短期内对国际干散货市场的影响存在于供需双侧,且以需求侧为主。国际干散货航运企业应积极应对新冠疫情带来的国际贸易波动,港口企业和政府部门也应在充分了解市场的情况下做出积极的运营管理规划和政策扶持。

INE原油期货上市影响研究

2018年3月26日,中国原油期货在上海期货交易所子公司上海国际能源交易中心(INE)正式挂牌交易,INE原油期货上市对我国能源行业具有重要的战略意义及影响。INE原油期货借助交易品种的差异化竞争、通过人民币结算等便利条件迅速打开原油期货交易市场,为我国石油行业经营参与者积极参与原油市场、套期保值、对冲交易风险、实现实物库存保值等提供了有利工具。