Changes in the Chemical Components of Light Crude Oil During Simulated Short Term Weathering

To unambiguously identify spilled oils and to link them to the known sources are extremely important in settling ques-tions of environmental impact and legal liability. The fate and behavior of spilled oils in the environment depend on a number of physicochemical and biological factors. This paper presents the results regarding changes in chemical composition of light crude oil during simulated short-term weathering based on natural environmental conditions. The results show that the saturated hydrocarbons of the light crude oil mainly distribute between n-C8 and n-C23 and the most abundant n-alkanes are found in the n-C10 to n-C16. The main chemical components of the light crude oil are n-alkanes and isoprenoids. The aromatic compounds are subordinate chemical components. Under the conditions of the weathering simulation experiment,n-alkanes less than n-C12,toluene and 1,3-dimethyl ben-zene are lost after 1 d weathering,the n-C13,n-C14,naphthalene and 2-methyl-naphthalene are lost on the fifth day of weathering,and n-C15 alkane components show certain weatherproof capability. The ratios n-C17/pristane and n-C18/phytane are unaltered and can be used to identify the source of the light crude oil during the first 8 d of weathering. After 21 d,the ratio pristine/phytane can not pro-vide much information on the source of the spilled light crude oil. Triterpanes(m/z 191) as biomarker compounds of light crude oil are more valuable.     

UNUSUAL DISTRIBUTION OF TRITERPANE AND STERANE TERRESTRIAL BIOMARKERS IN YACHENG CONDENSATES FROM YING-QIONG BASINS, SOUTH CHINA SEA

The condensates from the Yacheng Gas Field, Ying-Qiong Basins, have unusual chemical characteristics, with distribution dominated by terpanes and steranes derived from higher-plants. Pr/Ph ratios (6- 11 ) are very high. Drimane, cadinanes and homocadinanes exist in high concentration. Anomalously abundant 18α(H)-oleanane and remarkably abundant bicadinanes are present in Yacheng condensates, while 17α( H)-hopanes are in extremely low concentration. Taraxastane and significantlyabundant 17α(H)-diabopanes occur in the condensates. In addition, a number of C29 and C30 unknown pentacyclic triterpanes were monitored in the condensates, some of which are abundant. The unknown compounds may be terrestrial biomarkers or their occurrence may suggest a sub-oxic (dyacrobic) clay-rich depositional environment. C29 homologues are relatively predominant in regular and rearranged steranes. The concentration of diasteranes is markedly higher than that of regular steranes. The characteristics of Yacheng condensates are indicative of terrestrial source input. Based on condensate-condensate and con-densate-rock correlations, combined with results of studies on sedimentary facies. Yacheng condensates may be sourced from Yacheng and Lingshui Formations in the Qiongdongnan Basin. The maturity of Yacheng condensate is relatively high, at late oil window stage ( corresponding to 0.9 % - 1.3 % R0 ),based on sterane and terpane maturity parameters.     

Geochemistry and genesis on saturated hydrocarbon of crude oils in Gas Hure Oilfield in Qaidam Basin

Gas Hure Oilfield is the biggest one in the Qaidam Basin.Through intensive sampling and GC-MS analysis,the authors analyzed the geochemical characteristics of the crude oils in the Gas Hure Oilfield.The results show that the crude oils have even-odd carbon predominance for n-alkanes.In shallow reservoir,part of crude oils suffered biogenic degradation.As for normal oils,they have low Pr/Ph ratios with abundant gammacerane and C35 homohopane,which indicate that the crude oils are formed in strong reducing sa...     

维生素E醋酸酯对鱼油脂肪酸含量变化的影响

新鲜鱼油中添加05、0、2505、00 mg/kg 4种不同浓度的维生素E醋酸酯,在实验的第6、14、28、36和68天测定鱼油中的脂肪酸含量。结果表明:在500 mg/kg添加量内,维生素E醋酸酯对鱼油中脂肪酸含量没有显著性影响(P>0.05)。在实验期间,EPA(C20:5)、DHA(C22:6)、亚油酸(C18:2)含量明显下降,ARA(C20:4)、亚麻酸(C18:3)先升后降,棕榈酸(C16:1)逐步上升;C14含量逐渐增加,C17则先降后升,C16和C18在实验后期有较大提高。维生素E醋酸酯对鱼油中不饱和脂肪酸效用系数大小依次为:ARA>EPA>DHA>C18:3>0>C16:1>C18:2>C18:1,对ARA抗氧化效用最大,效用系数达到10.193%,C20:5为0.490%,C22:6为0.364%;维生素E醋酸酯对饱和脂肪酸效用系数大小依次为:C14>C17>0>C18>C16。     

渤中凹陷西南洼东营组烃源岩地球化学特征及环境指示意义

东营组烃源岩在渤中凹陷广泛分布,明确该套烃源岩特征及其形成的古环境对于推动渤中凹陷常规-非常规油气勘探具有重要意义。通过对渤中凹陷西南洼东营组烃源岩样品进行有机、无机地球化学实验,分析该套烃源岩品质、有机质来源和古沉积环境,并与凹陷内主力烃源岩沙河街组进行对比分析。结果显示：(1)东营组不同层段烃源岩特征差异显著,且与沙一二段烃源岩呈现明显不同。东二下段与东三段有机质丰度高,已达到成熟-高成熟阶段,东营组整体有机质类型均以Ⅱ型为主;(2)通过Pr/nC₁₇-Ph/nC₁₈等图版以及干酪根类型判断东营组有机质来源为混合型,与沙一二段的低等藻类输入明显不同;(3)综合Sr/Cu、Mn/Fe等16种元素含量或比值以及Pr/Ph、伽马蜡烷指数分析烃源岩形成时期的古环境,与沙一二段烃源岩干旱气候下强还原咸化湖盆的形成环境所不同,东营组整体形成于温湿气候下,伴随较强陆源输入,受控于弱氧化淡水环境;纵向上,从东三段-东一段古气候变化不大,水体盐度基本一致,但水深逐渐变浅,水体氧化条件呈现逐渐增强的趋势;(4)利用Co、La含量定量恢复东营组沉积时的古水深,...     

西湖凹陷古近系地层水中烃类的地球化学特征

作为油气中有机组分残留在地层水中的直接显示，研究地层水中烃类的地球化学特征对分析油气的沉积环境、生源母质、成熟度等具有重要参考意义。通过对西湖凹陷古近系平湖组和花港组地层水萃取烃类分析后发现:烃类来源于氧化环境下的陆源有机质输入，现均已达到成熟-高成熟阶段。其中黄岩构造带、天台构造带和西次凹的烃类以来自黏土矿物含量颇为丰富的泥岩为主，而平湖斜坡带的源岩缺乏黏土矿物，更可能以煤为主。天台构造带的地层水中烃类很特殊，其姥植比异常高，二萜类具有蕨类植物和裸子植物双重贡献的特征，不同于其他构造带的二萜类以裸子植物来源的特点。进一步研究发现天台构造带原油的姥植比和二萜类特征与其地层水一致，同样具有特殊性，且多种芳烃地球化学参数也均不同于其他构造带，因此推断天台构造带的原油是不同于其他构造带的特殊类型。天台构造带地层水中烃类的特殊性是推断其原油为特殊类型的有力入口，对进一步研究天台构造带的特殊原油提供了指示意义。      

Geochemistry and genesis on saturated hydrocarbon of crude oils in Gas Hure Oilfield in Qaidam Basin

Gas Hure Oilfield is the biggest one in the Qaidam Basin.Through intensive sampling and GC-MS analysis,the authors analyzed the geochemical characteristics of the crude oils in the Gas Hure Oilfield.The results show that the crude oils have even-odd carbon predominance for n-alkanes.In shallow reservoir,part of crude oils suffered biogenic degradation.As for normal oils,they have low Pr/Ph ratios with abundant gammacerane and C35 homohopane,which indicate that the crude oils are formed in strong reducing salt water environment.Compared deep(E13) reservoir with shallow(N1-N12) reservoir,the ancient salinity of sedimentary environment of N1--N12 crude oils is slightly higher than that of E13 crude oils;the C-21/C+22 ratios of crude oils are 1.02-1.71 with a higher abundance of C27 sterane,which shows that their mainly origin matrix are bacteria and algae;the C29 sterane 20S/(20S+20R)is generally low,the ratio in deep E13 reservoir distributes between 0.31 and 0.40,but in shallow reservoir is relatively low with 0.29-0.36.At the same time,C29 sterane αββ/(αββ+ααα)and Ts/Tm both are extremely lower.All the above show that the crude oils in Gas Hure are mainly low mature oils,although the maturity of deep reservoir crude oils is slightly higher than shallow one.     

催化剂与碱性缓冲液作用下欢喜岭油田稠油水热裂解反应实验

模拟注蒸气油藏条件,开展催化剂与碱性缓冲液作用下欢喜岭油田稠油的水热裂解反应模拟实验,向高温高压反应釜中加入稠油、水、催化剂、碱性缓冲液和油层矿物,在160～300℃温度下反应24～240h,测定反应前后稠油黏度、SARA族组成和元素组成,考察催化剂、反应时间、反应温度、油层矿物及铵盐碱性缓冲液等因素的影响.结果表明:在油溶性催化剂FeA2作用下,欢喜岭油田稠油在水热裂解反应后黏度显著降低,添加0.010mol/L的催化剂FeA2在240℃下反应24h可使稠油黏度降低62.4%;铵盐碱性缓冲液对稠油水热裂解反应具有协同催化作用,添加0.010mol/L的催化剂FeA2和质量分数为3.0%的铵盐碱性缓冲液在240℃下反应24h可使稠油黏度降低90.1%.稠油井经过水热裂解处理后周期产油量明显增加,周期油气比大幅提高,并且催化剂与碱性缓冲液协同处理的开采效果要明显好于催化剂处理的.添加催化剂与碱性缓冲液的水热裂解开采技术可应用于提高蒸气吞吐和蒸气驱等热采井的产量和采收率.     

昌乐五图煤田油页岩地质特征及质量分析

五图煤矿油页岩广泛分布于李家崖组的B段、C段和D段,以C段为主体,探明储量2.72亿t,是褐煤的伴生矿种。C段油页岩层密集,厚度大;D段上部含油页岩,但厚度小。油页岩焦油产率最高16.25%,最低5.43%,平均8.36%。基准发热量最高8.72MJ/kg,最低6.16MJ/kg,平均6.91MJ/kg。油页岩作为固态燃料,是汽油的替代能源,五图煤田油页岩资源的开发和利用前景广阔。     

生物标志化合物对于煤炭产地溯源的指示

为了保障进口煤炭质量和安全, 急需建立起一套行之有效的产地溯源方法对进口煤炭进行产地溯源和掺假识别。利用气相色谱-质谱联用仪(GC-MS)对来自5个进口国家的煤炭样品进行了分析, 并对有机质中代表性生物标志化合物进行了定性和定量分析, 以期对煤炭产地溯源新方法新技术提供启示。结果表明: 根据样品饱和烃Ph/nC₁₈和Pr/nC₁₇关系结果认为这5个国家的煤炭样品基本都处于低成熟-成熟阶段, 澳大利亚、俄罗斯、马来西亚和菲律宾的煤炭主要为陆源氧化环境下的Ⅲ型有机质; 除来自印度尼西亚的c56号样品外, 印尼其他煤炭样品和菲律宾全部煤炭样品的正构烷烃分布以中高相对分子质量为主, 暗示母质来源可能为陆源高等植物。研究结果证明不同的样品来自于不同的沉积环境, 有着不同的有机质输入类型等, 采用特定的指标可在一定程度上对溯源可起到指示作用。      

Activity of Changbaishan Tianchi Volcano Since Late Pleistocene--The Constrain From Geochronology of High Precision U- Series Tims Method

11 samples of lava and pumice from the cone of Changbaishan Tianchi Volcano, Jiling, China, were dated by using high precision U - series TIMS method. We conclude that the bottom of the cone formed before 350 ka, the middle part in 70～80 ka, the upper during 20～ 1ka, and the top less than 1ka, and the age based periods of the volcano eruption since Late Pleistocene is given as follows: ＞ 350ka, 70ka, 18 ～ 25ka, 10ka, 4C5ka, 1～0.75ka, which may offer the basis for the study of volcanic disaster in future. In addition, the principle of dating young volcanic rocks by using U - series TIMS method is introduced briefly. Differentiation characteristics of U and Th in different minerals of the volcanic rocks are discussed, and the ability producing isochrons, based on U and Th differentiation, are discussed. In the last part of the paper,the closure of samples to the elements U and Th, which is important for age results, is discussed by using (234U/238U)radioactivity ratio which can be used to monitor if the samples have been weathered or eroded or leached since the time they formed. In this study, all samples have (234U/238U) activity ratios within 1% of secular equilibrium ((234U/238U) radioactivity ratios are unity), indicating no disturbance of the 234U- 238U system. All of these discussions show that the TIMS method is good to date Tianchi volcanics and the results are reliable.     

Elemental and Isotopic Signatures in the Sediments Influenced by Seal Excrement on Antarctic Fildes Peninsula and Their Po- tential Paleoecological Applications

The elemental and isotopic signatures in the sediments influenced by seal excrement on Antarctic Fildes Peninsula are examined for their potential palaeoecologlcal applications. The seal hair abundance in sediments exhibits remarkable fluctuation versus depth, indicating similar changes in historical populations of the seals visiting the marine terrace. The combination of δ^13 C, total organic carbon concentration （TOC）, total nitrogen concentration （TN） and atomic C/N ratio shows that the organic matters in sediments with numerous seal hairs have a marine origin and are predominantly derived from seal excrements. The large δ15 N values in sediments are attributed to trophic enrichment and NH3 vollatilization processes. The large variations in the δ^15 N values and the negative correlation between the δ15 N values and the seal hair abundances seem to be the results of changes in the paleoclimates and the volatilization rates of the ammonia produced in the seal excrements. The 87 Sr/86 Sr ratios in the acid-soluble fraction of sediments are interpreted as a mixture of the ones from the seal excrements （30%-50%） and the chemically weathered local bedrocks （70%-50%）. The calculated proportion of seal-derived Sr based on the ^87 Sr/^86 Sr ratios has a significant correlation with seal hair abundances in sediments. These results suggest that δ15 N values and the ^87 Sr/^86 Sr ratios in the acid-soluble fraction of sediments were influenced by seal excrements, similar to seal halt numbers, and thus can potentially be used to estimate the historical seal population in the Antarctic region.     

Investigation of fractured rock aquifer in South China using electrical resistivity tomography and self-potential methods

Assessment of fractured rock aquifers in many parts of the world is complicated given their strong heterogeneity. Delineation of the subsurface geological formation in the weathered terrain is essential for groundwater exploration. To achieve this goal, 2D electrical resistivity tomography(ERT) and self-potential(SP) in combination with joint profile method(JPM) and boreholes have been carried out to delineate the subsurface geological units, detect the fracture/fault zones in hard rock, monitor the groundwater flow, and estimate the groundwater reserves contained within the weathered terrain at a complex heterogeneous site of Huangbu, South Guangdong of China. The integration of resistivity images with the borehole lithology along three profiles delineates three subsurface distinct layers namely topsoil cover, weathered and unweathered layers. The incorporation of ERT and SP with JPM reveal five fractures/faults, i.e., F_1, F_2, F_3, F_4 and F_5. 2D ERT models interpret the less resistive anomalies as the fractures/faults zones, and high resistive anomalies as the fresh bedrock. The inversion program based on the smoothness-constraint is used on the resistivity field data to get more realistic three layered model. SP measurements are obtained along the same electrical profiles which provide the negative anomalies clearly indicating the groundwater preferential flow pathways along the fracture/fault zones. Hydraulic parameters namely hydraulic conductivity and transmissivity were determined to estimate the groundwater resources contained within the fractures/faults. The integrated results suggest that the fractures/faults zones are most appropriate places of drilling for groundwater exploration in the investigated area. Geophysical methods coupled with the upfront borehole data provides better understanding about the conceptual model of the subsurface geological formations. The current investigation demonstrates the importance of the integrated geophysical methods as a complementary approach for groundwater assessment in the hard rock weathered areas.     

Virtual Huanghe River System： Framework and Technology

1 Introduction Huanghe (Yellow) River basin is located in 32°–42°N, 96°–119°E. The area of the catchment is more than 752,000km2. The river is 5464km long with a drop in elevation of 4830m. Among the whole area, the moun- tainous and stone area accounts for 29%, loess and hills area 46%, sandy area 11% and plain area 14%, respec- tively. Different natural landscapes exist in this area. The Huanghe River flows through the Loess Plateau, where the soil is eroded seriously (Wang, 2002;…     

The in vitro effects of steroids,human chorionic gonadotropin and cyanoketone on germinal vesicle breakdown of striped mullet (Mugil cephalus L.) oocytes

The in vitro effects of steroids, human chorionic gonadotropin (HCG) and cyanoketone on germinal vesicle breakdown (GVBD) of striped mullet (Mugil cephalus L.) oocytes were investigated. All concentrations of HCG (5,10,50 I.U./ml), progesterone and pregnenolone at the highest concentrations(lug/ml) were moderately effective in inducing GVBD, whereas 17β-estrodiol, cortisol, testosterone, 11β-hydroxyandrostenedione and 11-ketotestosterone did not stimulate GVBD. 17α, 20βdihydroxy-4-pregnen-3-one (17α, 20βdiOHprog) and deoxycorticosterone (DOC) were the most potent steroids in stimulating final oocyte maturation. The results indicate that C21 hydroxylated steroids are potent inducers of final maturation in mullet. Further, co-incubations with 17β-estradiol, cortisol and testosterone did not alter the maturation-inducing effects of HCG or 17α,20βdiOHprog. Cyanoketone, a blocker of 3βHSD activity, was only partially effective in blocking GVBD induced by HCG. This suggests that Δ5 (pregnenolone derived) and Δ4 steroids may be involved in final oocyte maturation in this species.     

莺歌海盆地LD区块地层超压对泥岩成岩作用的影响及其地质意义

在综合前人研究基础上,应用X衍射、薄片鉴定、热解分析、生物标志化合物研究等技术,并与邻区的常压环境下的相关特征进行了对比,深入分析了莺歌海盆地LD区块地层超压的分布状况及其对黏土矿物转化和有机质热演化的影响。结果表明,①研究区内,超压顶界面深度从盆地中心向边缘逐渐变深;②研究区内,超压顶界面之上,随埋深和地温的增大,蒙脱石、伊蒙混层中蒙脱石和高岭石的含量逐渐降低,而伊利石和绿泥石含量逐渐增加,但超压顶界面附近及往下时,黏土矿物各组分的含量几乎不再减少,受到了地层超压作用的抑制;③Pr/nC₁₇和Ph/nC₁₈随深度增大而降低,但在强超压顶界面以下,变化趋势发生逆转,出现微弱增大的趋势,超压顶界面以下的实测R_o值即有机质的成熟度也出现了明显的低异常。地层超压通过抑制黏土矿物转化,间接减弱了储层的胶结作用,有利于深层优质储层的形成。研究区地层超压抑制了有机质的热演化,地层超压对生烃的抑制作用扩大了研究区有效源岩的层位和体积,并使主力源岩的生、排烃期后移,从而有利于油气的晚期快速聚集成藏。      

稠油蒸气—泡沫驱不同油藏区域流体的流变特征

针对稠油蒸气-泡沫驱蒸气腔驱油区泡沫油体系、热水冷凝区热水油体系,通过模拟实际油藏温度压力条件,利用高温高压流变仪,在0～600s-1剪切速率范围内,研究蒸气相饱和度、泡沫剂质量分数、温度和蒸气干度对泡沫油体系流变特征的影响;在0～100s-1剪切速率范围内,研究热水相饱和度、泡沫剂质量分数和温度对热水油体系流变特征的影响.结果表明,泡沫油体系和热水油体系均为假塑性流体,可用幂律模型来描述,并且随着蒸气相饱和度和泡沫剂质量分数升高,泡沫油体系非牛顿性增强;随着温度和蒸气干度增大,泡沫油体系越接近为牛顿流体;随着热水相饱和度和温度升高,热水油体系越接近为牛顿流体;随着泡沫剂质量分数增加,热水油体系非牛顿性增强.     

MODERN CLIMATIC SIGNALS DEDUCED FROM STABLE ISOTOPE IN SHELLS IN XINGCUO LAKE SEDIMENTS,EAST TIBETAN PLATEAU,CHINA

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Fatty Acid Composition of Euphausia superba,Thysanoessa macrura and Euphausia crystallorophias Collected from Prydz Bay,Antarctica

The information of trophic relationship is important for studying the Southern Ocean ecosystems.In this study,three dominant krill species,Euphausia superba,Thysanoessa macrura and Euphausia crystallorophias,were collected from Prydz Bay,Antarctica,during austral summer of 2009/2010.The composition of fatty acids in these species was studied.E.superba and T.macrura showed a similar fatty acid composition which was dominated by C14:0,C16:0,EPA(eicosapentenoic acid) and DHA(decosahexenoic acid) while E.crystallorophias showed higher contents of C18:1(n-9),C18:1(n-7),DHA and EPA than the former two.Higher fatty acid ratios of C18:1(n-9)/18:1(n-7),PUFA(polyunsaturated fatty acid)/SFA(saturated fatty acid),and 18PUFA/16 PUFA indicated that E.crystallorophias should be classified as a typical omnivore with a higher trophic position compared with E.superba and T.macrura.     

The disastrous 23 July 2009 debris flow in Xiangshui Gully, Kangding County, Southwestern China

On 23 July 2009, a catastrophic debris flows were triggered by heavy rainfall in Xiangshui gully, Kangding county, southwestern China. This debris flow originating shortly after a rainstorm with an intensity of 28 mm per hour transported a total volume of more than 480×103 m3 debris, depositing the poorly sorted sediment including boulders up to 2-3 m in diameter both onto an existing debris fans and into the river. Our primary objective for this study was to analyze the characteristics of the triggering ra...