金刚烷类化合物的热稳定性研究及其地质意义

金刚烷类化合物由于其强抗热降解的能力对揭示深层油气藏的地化信息具有重要价值。对金刚烷类化合物热稳定性和裂解演化规律的研究较少,制约了金刚烷类化合物指标的实际应用。选择3种典型的金刚烷化合物(单金刚烷、1,3-二甲基单金刚烷和双金刚烷)作为模型化合物,分别开展金刚烷类化合物单体的黄金管封闭体系裂解动力学实验,以此揭示金刚烷类化合物的热稳定性和裂解演化规律。结果显示:单金刚烷和1,3-二甲基单金刚烷具有相似的热稳定性,均在Easy R_o值为1.5%时发生裂解,而双金刚烷具有更高的热稳定性,在Easy R_o值达到1.8%时才发生裂解,它们的裂解产物包括以甲烷为主的气态烃、以萘系列化合物为主的芳烃和其他同笼状单元数的金刚烷类化合物;当Easy R_o值分别小于2.1%、2.5%和2.5%时,单金刚烷、1,3-二甲基单金刚烷和双金刚烷的单体C同位素组成几乎不变。以上结果表明,金刚烷类化合物的热稳定性与分子结构中笼状单元的数目有关,分子结构中所带的甲基不会明显影响其稳定性;金刚烷类化合物的单体C同位素组成在较宽的成熟度范围内不变,可以...     

白云凹陷原油金刚烷化合物研究

针对白云凹陷油气共存的分布格局,轻质油藏、挥发性油藏及凝析油气藏中原油或凝析油因常规的甾萜类异构化参数等均已接近或达到其平衡值,难以有效判断其成熟度,导致无法准确界定该区挥发性油藏及凝析油为原生热成因抑或油藏受晚期天然气改造而成的次生成因的问题。本次研究采用气相色谱-质谱-质谱(GC-MS-MS)方法对白云凹陷原油及凝析油中金刚烷类化合物进行分析及绝对浓度测定,通过金刚烷参数指标对已发现原油及凝析油成熟度进行了界定,并探讨凝析油成因。研究表明,白云凹陷不同构造原油及凝析油成熟度差异大,白云主洼北部番禺低隆起和白云东洼凝析油金刚烷浓度在5000～10000μg/g之间,为高成熟阶段与天然气伴生的原生性凝析油,根据金刚烷指标参数推算的等效镜质组反射率(Rc)为1.3%～1.6%;白云东洼原油、白云主洼东部凝析油与挥发性油藏、油藏轻质油以及白云西洼挥发油、轻质油金刚烷浓度多在4000μg/g以下,为生油高峰后期产物,根据金刚烷指标参数推算的Rc为1.1%～1.3%,且白云主洼东部、白云西洼凝析油及挥发油可能为成熟阶段的原油遭受天然气改造而成的次生凝析油或挥发油。     

黔北坳陷高演化海相烃源岩中金刚烷类化合物及其意义

饱和烃气相色谱-质谱联用仪(GC-MS)分析结果显示,黔北坳陷东皇剖面、玉京山剖面下志留统龙马溪组(S1l)烃源岩和黔南坳陷羊跳寨剖面下寒武统牛蹄塘组(?1n)烃源岩中存在C_0–4单金刚烷系列、C_0–3双金刚烷系列、C_0–2三金刚烷系列、C0–1四金刚烷系列和C0–1五金刚烷系列的复杂组合,而在中等成熟的地质样品(镜质组反射率Ro=0.9%～1.4%)中一般仅出现烷基单金刚烷系列或烷基单金刚烷系列与烷基双金刚烷系列的简单组合,表明不同金刚烷类化合物的组合特征是衡量其经历热演化作用强度的定性指标。但黔北坳陷B1井?1n烃源岩和六井剖面上震旦统陡山沱组(Z2ds)烃源岩中缺失此类化合物,这可能与这些老地层经历的热演化作用强度(类镜质组反射率介于4.0%～5.5%之间)超出了金刚烷类化合物的热稳定性极限,并使它们遭到了分解破坏有关。研究区高演化海相烃源岩中金刚烷类化合物的浓度和相关异构体比值均明显高于中等成熟湖相烃源岩,结合类镜质组反射率的实测值判断,表明它们是衡量地质样品中有机质成熟度的有效指标。玉京山剖面S1l烃源岩中高金...     

松节油加氢热解产物中单萜烷类化合物的初步研究

用雷尼镍为催化剂对松节油进行了加氢实验,获得顺蒎烷、反蒎烷、莰烷、异莰烷等单萜烷类化合物,采用气相色谱"反吹、微流控"技术的色谱-质谱分析方法,测得了它们的保留时间和质谱图,为进一步研究原油或抽提物轻馏分中单萜烷类化合物的地球化学意义提供了一些基础性数据.     

气相色谱-质谱法快速测定罗氏海盘车中6种邻苯二甲酸酯类有机污染物

建立了气相色谱-质谱联用技术(GC-MS)测定罗氏海盘车中6种邻苯二甲酸酯类化合物(PAEs)的方法,采用丙酮-正己烷混合溶剂超声提取,通过中性氧化铝和弗罗里硅土填装层析柱净化样品,选用HP-5MS毛细色谱柱分离,选择离子监测模式(SIM)进行定性定量。该方法能同时分离测定罗氏海盘车中邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二正丁酯、邻苯二甲酸丁基苄酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二正辛酯等6种邻苯二甲酸酯类化合物。在优化条件下,方法标准曲线的相关系数为0.9975～0.9996,回收率为80.30%～119.00%,精密度(RSD,n=7)为2.2%～5.7%,方法最低检出限为10.00 ng/g。运用建立的方法对罗氏海盘车样品进行分析,检测出罗氏海盘车中含有邻苯二甲酸二异丁酯、邻苯二甲酸二正丁酯、邻苯二甲酸二(2-乙基己基)酯3种污染物,3种污染物含量均低于欧盟的限量标准,同时远低于其他各类食品中的检出含量,样品中邻苯二甲酸二(2-乙基己基)酯平均含量偏高。本法具有高的选择性、灵敏度和准确度,适用于罗氏海盘车中痕量PAEs的测定,为保护海洋环境及海洋资源开发提供技术支持。     

原油中常见化合物的全二维气相色谱—飞行时间质谱分析

全二维气相色谱-飞行时间质谱分析是近年来发展起来的一项全新的复杂混合物分离分析技术,该技术在分离石油烃类化合物方面显示出比传统一维色谱-四极杆质谱分析更强的优越性。通过不同类型原油的全二维气相色谱-飞行时间质谱分析,建立生物解降原油饱和烃组分和轻质原油烃类组分(饱和烃与芳烃)的分析方法,得到了甾烷、萜烷和芳烃化合物的二维平面点阵图和三维立体图。结果表明,该方法在原油的萜类化合物和轻质原油的饱和烃与芳烃同时分离方面取得了良好的结果,许多在普通一维色谱分析中不能分离或分离效果不佳的共馏化合物得到了很好的分离。     

塔北、塔中地区碳酸盐岩及其原油中的二苯并噻吩类化合物

塔里木盆地塔北、塔中地区四口井(库南1井,轮南46井,塔中12井和塔参1井)寒武-奥陶系12个碳酸盐岩烃源岩(泥灰岩,泥质灰岩和云岩)岩芯样品抽提物芳烃组分中的二苯并噻吩类化合物组成和丰度变化特征可分为三种类型:Ⅰ二苯并噻吩、甲基二苯并噻吩型;Ⅱ二苯并噻吩、甲基二苯并噻吩、二甲基二苯并噻吩+三甲基芴混合物型;Ⅲ二苯并噻吩、甲基二苯并噻吩、二甲基二苯并噻吩和三甲基二苯并噻吩型。研究的塔北、塔中隆起11个海相油二苯并噻吩类化合物分布类型均为二苯并噻吩、甲基二苯并噻吩、二甲基二苯并噻吩和三甲基二苯并噻吩型,和海相烃源岩二苯并噻吩类化合物第Ⅲ种分布类型完全相同。据此推断:塔北隆起8个海相油可能主要来源于塔北轮南地区下奥陶统;塔中隆起3个海相油可能来源于塔中地区中-上奥陶统。     

吹扫捕集-气相色谱-质谱法测定土壤中挥发酚的方法研究

文章研究了吹扫捕集-气相色谱-质谱法测定土壤中挥发酚的方法,分析了吹扫捕集各参数对挥发酚测定的影响,优化了吹扫捕集条件和气相色谱-质谱条件.通过与索氏提取技术对比,证明吹扫捕集-气相色谱-质谱法在实际样品检测中具有操作简便、分析周期短、试剂用量少、干扰小等优点,适用于测定沸点较低、溶解度较小的挥发酚,推荐选择经典的索氏提取技术测定沸点较高、溶解度较大的挥发酚.     

液液萃取-气相色谱-质谱法测定环境水体中18种多氯联苯

为准确、快速检测环境水体中多氯联苯(PCBs),建立了液液萃取-气相色谱-质谱法同时测定18种PCBs的分析方法。通过对样品前处理流程、气相升温程序、载气流速、进样口温度等参数的优化,采用 HP- 5MS UI色谱柱 (30 m × 0.25 mm×0. 25μm)对目标物进行分离,在电子轰击电离源下以选择离子监测模式（SIM）进行检测。结果表明18 种PCBs在5 ~ 100μg/L范围内呈良好线性关系,线性相关系数R2均大于0.995。空白中低、中、高三个不同添加浓度下的样品平均加标回收率为78.1% ~ 101%,相对标准偏差(RSD,n=6)为0.272% ~ 3.28%,方法检出限(MDL)在0.44 ~ 0.96 ng/L之间。本方法选择性好、灵敏度高、重现性好,应用于实际样品检测的加标回收率在70.8% ~ 104%之间,能够满足环境水体样品中18种多氯联苯同时检测的分析要求。     

吹扫捕集-气相色谱法测定水中七种氯苯类化合物

试验了三种色谱柱的分离效果,选用自制的环糊精毛细管柱,用吹扫捕集气相色谱法对水体中七种氯苯类化合物进行分析,优化了吹扫捕集的主要工作条件。方法的线性范围为1~100nL/L,重现性良好,6次重复测定的RSD为3.62%~6.98%。进样量5mL时,其检出限可达0.5nL/L,较之液液萃取灵敏度提高了至少50倍。     

A novel method for isolation of diamondoids from crude oils for compound-specific isotope analysis

A novel, effective and simple method based on adsorption chromatography on silica gel, adsorption on molecular sieves, and inclusion in β-cyclodextrin (β-CD) was developed to separate and enrich diamondoids directly from crude oil. In this method, diamondoids ranging from adamantanes to triamantanes were purified and isolated from the branched/cyclic hydrocarbon fraction of crude oil for further accurate analysis of stable carbon isotope ratios (δ¹³C) by gas chromatography-isotope ratio mass spectrometry (GC-irMS). A 5 mg/ml solution of β-CD stirred for 2 h was found to be sufficient for the inclusion of diamondoids and the inclusion complex completely breaks down by acidolysis in 1 mol/l hydrochloric acid at 80 °C for 16 h. The recovery of diamantanes was higher than that of other diamondoids. Our major finding is that the specific inclusion effect between β-CD and diamondoids can be utilized to isolate and concentrate diamondoid compounds from crude oil in a fast and effective way. It is a potential method to yield the diamondoid fraction amenable for compound-specific isotope analysis (CSIA), which markedly improves accuracy of molecular isotopic proxies of oil-oil and oil-source correlation.     

Comparison of Michigan Basin crude oils

Michigan Basin oils from the Ordovician Trenton, Silurian Niagaran, and Devonian Dundee formations have been geochemically compared by GC, GC-MS, and carbon isotope mass spectrometry. One oil from each formation was selected for detailed analysis which included measurement of individual n-alkane δ¹³C values. The Ordovician and Devonian oils are strikingly similar to one another, yet clearly different from the Silurian oil. This pattern is unexpected because Ordovician and Devonian reservoirs are physically separated by the Silurian strata. From time-temperature considerations, the Devonian oil probably was formed in older strata and has migrated to its present location. Our analyses suggest a common source for the Devonian and Ordovician oils.     

Comparison of crude oils and their alteration products

A simple method is proposed for using gas Chromatographic data on the high molecular weight saturated fractions of crude oils to make comparisons of source materials, migration mechanisms and, in particular, alteration processes within reservoirs. The preferential loss of normal alkanes by bacterial attack on a light crude is one of several processes readily followed using this scheme.     

The effect of evaporation on the concentration and distribution of diamondoids in oils

Diamondoids are commonly found in petroleum and sediments and have an inherent resistance to thermal and biological destruction, which means they can provide useful information in situations where conventional biomarkers cannot. Here, we present the results of an investigation of the effects of atmospheric evaporation on the concentration and distribution of low molecular weight diamondoids in four petroleum fractions (gasoline, condensate, diesel and fuel oil). These experiments indicate that both adamantanes and diamantanes evaporate with the other light hydrocarbons from oils and that variations in the concentrations of these compounds during evaporation are controlled by the type of petroleum fraction, the extent of evaporation and the boiling point of the diamondoid compounds within the oil. Evaporation has a significant effect on adamantane concentration ratios, whereas no changes in diamantane concentration ratios occur, suggesting that diamantane-based concentration and distribution indices can be used for the correlation of oils and determination of maturity even if oils have undergone evaporation. Some diamondoid concentration ratios, such as adamantane/1-methyladamantane, 1-methyladamantane/2-methyladamantane, 1-methyladamantane/1-ethyladamantane, 1-methyladamantane/4-methyldiamantane, adamantane/diamantane and 1,3-dimethyladamantane/4,9-dimentyldiamantane, progressively decrease with ongoing evaporation and are independent of petroleum fraction type, indicating that given the original unaltered index value, these indices can be used to deduce the relative extent of oil evaporation. The study also indicates that slight to moderate evaporation of oils leads to an increase in diamantane concentrations that is nearly proportional to the extent of oil evaporation, indicating that these compounds can be used as indices to estimate the extent of oil evaporation.     

原油含硫化合物分离及分析方法新进展

原油中含硫化合物组成与结构信息广泛应用于油气勘探、石油运输和炼化以及环境保护。目前,挥发性和半挥发性含硫化合物的研究相对成熟,但是对大分子含硫化合物的结构认识相对薄弱。本次研究系统调研了国内外含硫化合物的分离和分析方法,总结了各方法的原理、实验流程、优缺点、应用和意义。含硫化合物分离方法主要包括化学转化方法和柱层析分离方法,可以有效分离噻吩类、硫醚类、亚砜类、硫醇类以及含硫多环芳烃类化合物。高分辨质谱和全二维气相色谱对高分子含硫化合物表征提供了技术支持。总体而言,对高分子含硫化合物的分子结构、来源、成岩演化过程及其生物标志物等信息的研究相对欠缺,建议加强对低成熟高硫原油的研究,探索高分子含硫化合物的赋存形式和地球化学意义,为石油勘探开发进一步提供指导信息。     

水中亚硝酸根检测标准方法比较及其研究进展

对水中亚硝酸根检测的标准方法进行了比较,从方法原理、适用水质、检测范围、检出限、干扰因素、精密度和准确度等方面总结了各方法的特点,综述了最近三年亚硝酸根测定方法的研究进展.     

Comparison of bulk kinetic parameters for asphaltenes from long-time stored and related fresher-produced crude oils

Two investigated long-time stored oils, which were produced in the 1960s, show strong compositional changes compared to fresher oil samples from the same well and production zones. Asphaltenes isolated from stored and fresher-produced oil pairs show highly similar results from open-system pyrolysis. However, asphaltenes from long-time stored oils show higher reactivity compared to those from fresher oils. The study shows that differences exist in kinetic models based on asphaltenes from fresh-produced oil and those based on oil that has undergone long-term storage, and that these differences may impact geological predictions using such models. Factors controlling the chemical differences between stored and fresher asphaltenes are unclear and hard to determine, because of a broad range of factors controlling compositional differences between these oil pairs. The difference in chemical kinetics might be related to chemical storage effects, but different well-site sampling techniques between decades, or even incomplete homogenization of the long-time stored oils in barrels before sampling may also have an impact.     

Waxes and asphaltenes in crude oils

High molecular weight (HMW) hydrocarbons (>C₄₀) and asphaltenes are important constituents of petroleum and can cause problems related to crystallization and deposition of paraffin waxes during production and transportation as well as in the formation of tar mats. However, traditional methods to isolate asphaltene fractions, by adding 40 volumes in excess of low boiling point solvents such as pentane, hexane or heptane, can produce asphaltene fractions which are contaminated with a significant amount of microcrystalline waxes (>C₄₀). The presence of these microcrystalline waxes in the asphaltene fractions has the potential to provide misleading and ambiguous results in modeling and treatment programs. The sub-surface phase behaviour of an asphaltene fraction will be quite different from that of a wax-contaminated asphaltene fraction. Similarly accurate modelling of wax drop-out requires information on pure wax fractions and not asphaltene-dominated fractions. Hence the goal of this paper is to describe a novel method for the preparation of wax-free asphaltene fractions. In addition, this method provides a quantitative subdivision of the wax fraction into pentane soluble and insoluble waxes which, when correlated with physical properties of crude oil such as viscosity, pour point, cloud point, etc., may help explain causes of wax deposition during production, transportation and storage of petroleum.