High molecular weight (C35 +) n-alkanes of Neogene heavily biodegraded oil in the Qianmiqiao region, North China

With wax content of 1.62%, heavy oil has been produced from the sandstone reservoirs of Neogene Guantao Formation (Ng1^Ⅲ). In the GC and GC-MS RIC profiles of its aliphatic fraction, n-alkanes are totally lost, which shows the result of heavy biodegradedation. However, the remaining trace C₁₃－C₃₆ n-alkanes can be still seen from its m/z 85 mass chromatogram. In addition, a complete series of C₃₅－C₇₃ high molecular weight (HMW) n-alkanes was detected by high-temperature gas chromatography (HTGC). The HMW n-alkane series shows a normal distribution pattern, a major peak at nC₄₃, obvious odd-carbon-number predominance, CP_I37—55 and OEP_45—49 values up to 1.17 and 1.16—1.20 respectively. The present study not only has conformed the strong resistibility of HMW n-alkanes to biodegradation in crude oils as concluded by previous researchers, but also has provided some significant information on source input and maturity for the heavily biodegraded oil in the Qianmiqiao region.     

Identification of a novel HMW glutenin subunit and comparison of its amino acid sequence with those of homologous subunits

Aegilops tauschii is the donor of the D genome of common wheat (Triticum aestivum). Genetic variation of HMW glutenin subunits encoded by the Glu-1Dt locus of Ae. tauschii has been found to be higher than that specified by the Glu-1D locus in common wheat. In the present note, we report the identification of a novel HMW glutenin subunit, Dy13t, from Ae. tauschii. The newly identified subunit possessed an electrophoretic mobility that was faster than that of the Dy12 subunit of common wheat. The complete ORF of encoding the Dy13t subunit contained 624 codons (excluding the stop codons). The amino acid sequence deduced from the Dy13t gene ORF was the shortest among those of the previously reported subunits derived by the D genome. A further comparison of Dy13t amino acid sequence with those of the subunits characterized from the A, B, D, R genomes of Triticeae showed that the smaller size of the Dy13t subunit was associated with a reduction in the size of its repetitive domain.     

HMW glutenin subunits in multiploidAegilops species: composition analysis and molecular cloning of coding sequences

The Aegilops genus contains species closely related to wheat. In common with wheat, Aegilops species accumulate high molecular weight (HMW) glutenin subunits in their endospermic tissue. In this study, we investigated the composition of HMW glutenin subunits in four multiploid Aegilops species using SDS-PAGE analysis. Furthermore, by working with Ae. ventricosa, we established an efficient genomic PCR condition for simultaneous amplification of DNA sequences coding for either x- or y-type HMW glutenin subunits from polyploid Aegilops species. Using the genomic PCR condition, we amplified and subsequently cloned two DNA fragments that may code for HMW glutenin subunits in Ae. ventricosa. Based on an analysis of the deduced amino acid sequences, we concluded that the two cloned sequences encode one x- and one y-type of HMW glutenin subunit, respectively.     

山羊草四个组高分子量麦谷蛋白亚基组成分析

利用SDS-PAGE技术对山羊草属18个种的46份材料进行高分子谷蛋白亚基电泳分析．18个种各电泳出2～5条带，共有24种不同的电泳条带，26种不同的麦谷蛋白亚基类型，每个种有1～3种类型．山羊草与小麦的麦谷蛋白亚基存在着较大的差异，山羊草属中各种间在高分子量麦谷蛋白亚基组成与其亚基的电泳迁移率方面也存在广泛差异．     

甜菜高分子量核DNA的分离

研究了从甜菜中分离高分子量核DNA的方法．利用离心分离细胞核，经低融点琼脂糖块包埋、蛋白酶K原位裂解，结合低融点琼脂糖脉冲电泳去除淀粉制备高分子量核DNA．结果表明利用幼叶制备高分子量核DNA分子量高，更容易去除其中的淀粉；并且利用该方法得到的高分子量核DNA纯度高，适于部分酶切．     

安塞地区长10段原油地球化学特征及油源探讨

通过对安塞油田G52井长10段原油样品的地球化学分析,系统地研究了原油的分子标志化合物的分布特征,并且进行了油源对比.研究结果表明,长10段原油饱和烃中以低碳数正构烷烃分布为主,呈单峰态分布,主峰碳为nC21,无明显奇偶优势,规则甾烷中ααα20RC27,C28,C29呈"L"型分布,ββ构型甾烷丰度较高.萜烷系列中三环萜烷的丰度中等,五环三萜类中Ts,C29Ts以及18a(H)-重排藿烷的丰度明显偏高,伽马蜡烷指数较低,而常规的升藿烷系列化合物丰度不高,明显受成熟度的影响.由此表明长10段原油主要来源于淡水或微咸水的弱氧化-还原环境,是以低等水生生物或藻类输入为主的湖相烃源岩,而且已经达到高成熟阶段.G52井长10段与长6—长9段原油和研究区烃源岩生标分布以及相关参数对比表明,长10段原油与长9段烃源岩生物标志化合物特征具有相似性,初步认为长10段原油主要来自长9段烃源岩.     

Application of backflush and micro-flow techniques to the analysis of C5-C13 hydrocarbons in crude oils and its geochemical significance

An Agilent 6890N GC equipped with both FID and Agilent 5975 MSD analyzer has been employed to analyze C5-C13 hydrocarbon fractions of crude oils. A technical combination of program temperature volatilizer injection, backflush and micro-flow controller afforded a fine separation of C5-C13 compounds on a PONA column with the heavy part of crude oils being cut off before entering the analytical column. Both GC-FID chromatogram and GC-MS mass chromatograrns (MID and full scan) could be obtained at the same time. The retension time differences of nC6-nC13 alkanes between GC and TIC were in the range of 0.02-0. 58 minutes. Totally 286 peaks have been assigned group compositions. Results on 8 typical oil samples from CNPC Key Laboratory Crude Oil Library showed that the characteristics of C6-C13 hydrocarbon group composition could be used in oil-oil correlation studies.     

厌氧微生物对新疆六中区稠油的降解特性

厌氧微生物作为油藏中微生物的重要组成部分,受到人们越来越多的关注,但是关于对原油的降解效果和降解机制的研究报道较少.对发酵菌富集培养物和产甲烷菌富集培养物作用前后的原油进行色质联用分析,结果表明:产甲烷菌富集培养物作用后的原油,其原油族组成变化明显,饱和烃和胶质相对含量降低,而芳香烃和沥青质相对含量上升,其中正构烷烃的含量有所增加,尤其是大于C22的正构烷烃的含量增加明显,藿烷及其同系物的含量也都有所上升.而发酵菌富集培养物作用后,饱和烃、芳烃以及胶质含量都略有上升,变化最明显的沥青质作用后下降了2%,发酵菌富集培养物降解了原油中的杂环芳烃二苯并噻吩和二苯并呋喃.同时两种富集培养物对二环芳烃的降解作用明显.产甲烷菌富集培养物和发酵菌富集培养物作用后,新疆六中区原油中短链正构烷烃含量相对增加,而长链正构烷烃含量则相对减少,∑nC21-/∑nC22+值由作用前1.033分别下降到1.023和1.015,Pr/Ph的值基本都保持在0.945左右,但是Pr/nC17和Ph/nC18都有所增大.总的来说,产甲烷菌富集培养物对原油的降解作用更明显,两种不同厌氧微生物的富集培养物对原油的作用表现出了一定的选择性.     

旅大27-2油田稠油油藏流体流动性影响因素

旅大27-2油田开发已经进入到蒸汽吞吐中后期,目前油田含水上升快,蒸汽吞吐开发效果变差。为了更好地对旅大27-2油田进行储量评价以和开发动用。详细研究了稠油族组成、温度、油水乳化、压力、N_2溶解及降黏剂对旅大27-2油田稠油黏度的影响,然后通过流动性实验证实了稠油在储层中的流动性主要受到黏度的影响,明确了温度、油水乳化和降黏剂的使用是影响稠油黏度的主要因素。当温度从50℃升高到100℃时,旅大27-2油田稠油油样黏度从3 665 mPa·s降低到172 mPa·s,降低了95.31%;50℃时,70%含水原油黏度为不含水原油黏度的21.1倍;50℃、降黏剂含量为1.0%时,降黏率为94%。有效地避免或者减弱油水乳化形成油包水乳状液,是有效提高油田开发效果的重要途径。     

Application of C5-C13 light hydrocarbons in depositional envlrOnment diagnosis

Based on the geological background and Gammacerane/C31H(S+R)ratios,source rock depositional environments of the studied oil samples(194)from 13 oilfields were classified into three groups according to salinity:saline-lacustrine facies,fresh to brackish lacustrine facies(including linmetic facies),and semi-saline to saline facies(including marine facies of the Tarim Basin).C5-C13 compound groups in the crude oils were separated by GC,and about 286 compounds were qualitatively analyzed.The geochemical application of the C6-C13 compound groups and their ratios between each group with individual carbon number was investigated.Our studies show that(1)C6-C13 compound groups and their ratios in the crude oils could serve as new reliable parameters for oil-oil correlation because the C6-C13 light fractions are the major oil component,especially in light oil or condensate,in which they account for almost 90%of the whole oil;(2)the compound groups of C7 light hydrocarbons in oils derived from different depositional environments with different salinity have different characteristics;(3)C6-C13 compound groups and ratios may be affected by other factors such as maturity,but they are mainly controlled by salinity of depositional waters.     

柴达木盆地三湖坳陷气钾1井烃源岩地球化学特征分析

对烃源岩的地球化学特性的研究有助于油气的勘测。柴达木盆地三湖坳陷有丰厚的天然气资源,沉积范围广,厚度较大其厚度整体约2 000~3 200 m。选取三湖地区达布逊湖东部气钾1井的烃源岩样品,通过分析生物标志化合物,研究烃源岩的地球化学特征。实验结果表明:饱和烃的中低碳数分子无明显偶奇碳数优势,反映出微生物的降解作用明显改变了常规生物标志物的分布特征;有机质母质,植烷含量丰富,其碳数值接近于主峰碳数值,呈现弱还原的沉积环境特征;气钾1井中天然气有机母质主要来源于以陆生高等植物为主要母源的湖相沉积环境;伽马蜡烷也出峰明显,说明其沉积的水环境主要为高盐特征;正构烷烃C_(31)/C_(29)的比值表明这一期间的气候条件为寒冷干燥。     

海洋石油烃降解菌的降解性能与固定化研究

对2株海洋石油烃降解菌(HD-1和HD-2)进行了研究;采用气相色谱法分析了这2株菌对正构烷烃组分的降解情况。结果表明HD-1菌株对正构烷烃的降解性能优于HD-2菌株。碳链的长度对降解率有显著影响。C11能分别被HD-1和HD-2降解90.9%和73.8%,但C25却只能被降解73.3%和27.7%。采用麦饭石、孔质砂和稻壳碳固定混合菌液后,对培养液中柴油的去除率都明显高于未固定化的菌液的去除率,其中麦饭石固定化菌的去除率最高,达到98%。     

新疆引进小麦品种(系)的HMW-GS组成与沉淀值的关系

以新疆近年来引进的32个小麦品种(系)为材料,运用SDS PAGE技术系统分析了其高分子量谷蛋白亚基构成、不同等位基因间亚基变异,并研究了高分子量谷蛋白亚基构成对沉淀值的影响。结果表明:不同亚基对沉淀值的作用不同,其中5 10>2 12,1>N,7 8与7 9的作用相近;Glu l评分与沉淀值呈极显著正相关,r=0.775 。     

川东飞仙关组烷烃气碳同位素特征与成因分析

飞仙关组作为川东主力气层,陆续已经发现了普光、毛坝、东岳寨、渡口河等一系列大中型气藏,展示了极其重要的战略地位。目前常规的组成分析方法已经不能满足该层天然气类型及成因的判别要求。通过分析烷烃气碳同位素特征,判识天然气类型、分析其成因机制。实验分析显示部分样品C_1~C_3烷烃气的碳同位素比值呈δ~(13)C_1δ~(13)C_2δ~(13)C_3分布(倒转),显示为多源、多期天然气混入。同时根据C_1/C_2+C_3与δ~(13)C_1及ln(C_1/C_2)与In(C_2/C_3)的值域变化特征,最终判断川东大多气藏以原油裂解气为主,混入一定的煤型气。川东飞仙关组古油藏于晚侏罗世沉积期,其埋藏深度介于5 300~8 200 m之间,油藏温度普遍超过150℃,油发生热裂解,生成烷烃气及沥青,持续时间大于30 Ma。     

Research on C_3N_4 Superhard Compound Thin Film and Its Application

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Sn(OTf)_2催化活化D-A环丙烷的密度泛函研究(英文)

用量子化学密度泛函理论对路易斯酸Sn(OTf)2催化活化供电子-吸电子环丙烷的机理进行了量子化学研究.在B3LYP/6-31G计算水平全优化了反应势能面上所有驻点的几何结构,用自洽反应场极化连续介质模型分别在B3LYP/6-31G和B3LYP/6-311G(d,p)计算水平计算了单点溶剂化效应.结果表明,Sn(OTf)2催化活化D-A环丙烷是通过它们的配位作用增大C1-C(2)偶极矩和降低反键轨道σ*(C1-C2)的能量来实现的     

Holocene vegetation cover in Qin’an area of western Chinese Loess Plateau revealed by n-alkane

Previous studies have found that wetlands prevailed in western Chinese Loess Plateau and pine pollen could reach up to 80% in Qin＇an area of the plateau during middle Holocene. It was then deduced that forest vegetation covered Qin＇an area in a warm and wet climate during middle Holocene. The proxies of molecule biomarkers from two Holocene sections, a swamp-alluvial loess section and a typical Ioess-paleosol section are used to reconstruct regional vegetation history. It is found that the heavy-molecular-weight （HMW） homologues of the n-alkanes in all samples exhibit a pronounced odd-over-even predominance, maximizing at C31 and the abundance of the nC27-alkanes is the lowest in nC27, nC29, nC31, i.e. C27〈C29〈C31, a typical grass n-alkanes model. The results are the same as those of model surface soil samples under grass cover but different from both forest cover and modern pine leaves, which yield preferentially nC29-alkanes peak. It could be inferred that the area was dominated by grass cover but not forest cover during whole Holocene epoch. The study shows that combining both molecule biomarkers and pollen analysis can avoid the disadvantage of pollen analysis in reconstruction of regional vegetation cover.     

温度与表面活性剂协同作用下的特超稠油油水固界面行为分析

温度与表面活性剂都是影响稠油油水固流变性的重要因素;但目前针对稠油的流动性改善研究一直停留在以采收率增加量衡量流变效果的层面,忽略了从界面行为变化的角度上分析增强流动性的机理。针对以上问题设计了一系列测量不同因素对流变性、界面张力及接触角的影响试验,探究了温度与表面活性剂协同作用下是否会对改质降黏过程产生增效影响。结果表明稠油对温度敏感性较高,且升高温度与加入表面活性剂都可降低界面张力、改变润湿性、提高流动性。研究还发现,当二者协同作用时会比单一因素影响获得更好的降黏效果。     

海上油田高效开发技术探索与实践

在我国渤海湾相继发现40多亿t地质储量的原油,但这些原油多为稠油和重油,难以开发,在陆上油田开发经验不能用于海上,又无国际先例可借鉴的情况下,基于海上稠油开发历程及现状,深入分析了海上稠油油田开发面临的主要问题与挑战,有针对性地集成、创新了适合于海上稠油开采的先进技术,逐步建立完善了海上稠油高效开发思路和技术体系。该技术有效降低了油田开发成本,并成功地开发了被国际石油公司称为“21世纪挑战”的海上最大稠油油田。成功研发了开发海上边际油田的“三一模式”和“蜜蜂模式”,应用于渤海边际油田开发实践,并探索出一套适用于海上油田开发的优快钻完井技术。在此基础上,为了实现渤海油田产量进一步增长和大幅度提高采收率,经过长期技术探索与矿场实践,大胆提出了海上稠油高效开发新模式,即模糊一、二、三次采油界限,通过技术创新和创新技术集成,使油田在投产初期迅速达到高峰产量并高速开采,始终保持旺盛生产能力;采取多枝导流、控制适度出砂、早期注水、注水即注聚、注水注聚相结合等技术;通过以聚合物驱为主的提高采收率技术、多枝导流技术、电潜螺杆泵举升技术和地面除砂工艺等技术体系,在最短的时间内采出更多的原油,达到最大采收率。基于高效开发新模式思想,成功开发了迄今为止世界海上最稠的渤海南堡35-2油田,并已在多个油田进行应用。这一创新的认识与实践,不仅为我国海上油田开发探索出一条新路,也为世界海上油田,特别是稠油油田的开发提供了新思路的思考。     

塔里木盆地塔东英南2气藏气源分析

英南2凝析气藏天然气属富氮湿气,烃类气体体积分数一般为78.86%~87.67%;甲烷68.92%~76.67%,重烃气体为9.17%~14.01%,非烃气体氮气为13.89%~21.07%,甲烷和乙烷的碳同位素分别为-38.6‰~-36.2‰和-30.9‰~-34.7‰.根据天然气组分、天然气碳同位素的特征,认为英南2凝析气藏的天然气来源于高过成熟的下古生界海相寒武系—下奥陶统腐泥型干酪根形成的原油裂解气,同时应用ln(C2/C3)-ln(C1/C2)及δ13C2-δ13C3与ln(C2/C3)判识模式也印证了英南2气藏气源为原油裂解气,气藏凝析油中存在高含量的金刚烷,指示原油经历了裂解,裂解程度为80%~90%.