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1.
从普光气田及邻近地区二叠系和下三叠统15个含沥青碳酸盐储集岩样品分步提取了自由态油气组分和油气包裹体组分,并且应用限定体系(金管)热解实验获取了固体沥青热解组分.各组分进一步做色谱和色谱-质谱分析获取了生物标志物组成.分析结果表明,从油气包裹体组分、自由态油气组分至固体沥青热解组分,伽马蜡烷/C31升藿烷比值依次增高.同时油气包裹体组分 C23三环萜烷/(C23三环萜烷+C30藿烷)、C21/(C21+ΣC29)甾烷、C27重排甾烷/(C27重排甾烷+C27规则甾烷)、20S/(20R+20S) C29甾烷和αββ/(ααα+αββ) C29甾烷等成熟度指标与自由态组分相近,而明显高于固体沥青热解组分.根据分子指标,可以推断古油藏的原油来源于不同的烃源岩,早期充注的原油来源于下志留统烃源岩,具有较低的伽马蜡烷含量和较高的成熟度;晚期充注的原油来源于上二叠统烃源岩,具有较高的伽马蜡烷含量和较低的成熟度.固体沥青主要为晚期充注、来源于上二叠统烃源岩的原油裂解生气的产物  相似文献   

2.
银根-额济纳旗盆地原油的发现及其主要地球化学特征   总被引:9,自引:1,他引:9  
在银根-额济纳旗盆地东部查干凹陷和西部路井凹陷首次发现了轻质低硫成熟原油,其饱和烃含量在80%以上,非烃和沥青质含量低;饱和烃和芳烃成熟度参数表明它们均为成熟原油,其成熟度相当于镜质相反射率Ro0.8%-1.1%阶段,是生油高峰阶段的产物。原油全油碳同位素δ^13C值小于-31‰。生物标志物中类异戊二烯含量较高,植烷与姥鲛烷均势;查干凹陷原油三环萜烷含量高于五环萜烷,而路井凹陷原油三环萜烷含量相对较低;两原油中均含有较高的Ts,C29Ts,C30重排藿烷和伽马蜡烷,藿烷为主,C32以上升藿烷含量极低;孕甾烷含量较高,尤其是查干凹陷原油;甾烷中以C29甾烷为主,约占50%,C27和C28甾烷基本均势,异胆甾烷含量高于胆甾烷;重排甾烷含量低,甾烷的含量与萜烷含量相当,这些特征表明原油是典型的湖相原油,其主要的烃源岩是下白垩统湖相源岩而非侏罗系煤系烃源岩。  相似文献   

3.
塔中421井和塔中402井石炭系油层2个原油样和8个油砂样连续抽提组分甾烷、萜烷分布特征和正构烷烃单体碳同位素组成具有明显的差异,具有不同的来源。塔中421井上石炭统3个油砂样自由态组分、束缚态组分和油气包裹体具有伽马蜡烷和C28甾烷相对含量高、正构烷烃单体碳同位素组成重的特征,划分为Ⅰ类原油,对比认为主要来源于寒武系-下奥陶统烃源岩。塔中421井和塔中402井上石炭统的2个油样具有伽马蜡烷和C28甾烷相对含量低、并且正构烷烃单体碳同位素组成轻的特征,划分为Ⅱ类原油,其来源尚不明确。塔中402井石炭系上、中和下统的5个油砂样各类组分具有介于Ⅰ、Ⅱ类原油之间的特征,为Ⅰ和Ⅱ类原油的混合物。5个油砂样从自由态组分、束缚态组分至油气包裹体Ⅰ类原油含量依次增高,Ⅱ类原油含量依次降低。2口井8个油砂样从自由态组分、束缚态组分至油气包裹体C23三环萜烷/(C23三环萜烷+C30藿烷)和C21/(C21+∑C29)甾烷比值都依次降低,反映了油气充注过程中,原油成熟度不断升高。塔中4井区储层油砂不同吸附态烃类分子与碳同位素的研究结果反映塔中4油田具有多种油气来源,经历长期油气充注过程,寒武系-下奥陶统烃源岩在地史上对该区具有成烃贡献。  相似文献   

4.
流体包裹体成分分析技术(MCI)是应用分子有机地球化学参数研究烃类包裹体成分的一种方法。它与常规技术相比具有三个显著优点:可以分析包裹体内烃类组成,达到分子级水平;使用化学试剂氧化处理包裹体表面污染物,避免高温操作影响流体包裹体烃类组成;空白实验贯穿全过程以确保包裹体的清洁性。该技术能够成功解决源岩、成熟度、油气充注期次及油气二次蚀变等问题。选取塔中47井石炭系和志留系的两块样品进行了MCI分析,取得正构烷烃、萜烷、甾烷等分布参数。结果显示,塔中47油藏中石炭系与志留系原油属同源;与油砂抽提物相比,包裹体烃类的成熟度较低;志留系油砂与包裹体烃类有不同的母源;志留系中至少存在两期油气充注,其晚期充注的油气有轻微水洗或生物降解作用。  相似文献   

5.
通过对准噶尔盆地中Ⅲ区块的原油或油砂抽提物饱和烃与芳烃气相色谱-质谱分析,研究了原油及油砂抽提物中的正构烷烃、类异戊二烯烷烃、β-胡萝卜烷以及甾萜烷烃系列化合物的分布特征,对原油类型进行了划分,并对其油源做了初步的分析。研究表明,中Ⅲ区块原油可划分为3种类型:第Ⅰ类包括永6井与永9井白垩系吐谷鲁群原油及油砂抽提物,主要来自于中二叠统乌尔禾组烃源岩;第Ⅱ类包括永1井西山窑组和三工河组原油及油砂抽提物、永2井西山窑组油砂抽提物及永3井西山窑组和三工河组原油,为二叠系和侏罗系烃源岩生成的混源油;第Ⅲ类包括永6井西山窑组油砂抽提物和永2井西山窑组下部原油,主要来源于侏罗系烃源岩。  相似文献   

6.
对鄂尔多斯盆地东胜地区中侏罗统直罗组砂岩中烃类包裹体进行镜下观察、描述,利用压碎抽提法对烃类包裹体进行色谱—质谱分析,并与白垩系油苗、三叠系油砂及源岩抽提物进行对比,目的是探讨其来源。包裹体油生物标志物成熟度参数,C29ααα甾烷20S/(S+R)、C32αβ藿烷22S/(S+R)比值基本达到平衡值,利用甲基菲指数计算的镜质体反射率参数介于0.64%~0.82%之间,显示包裹体中石油烃已接近成熟—成熟热演化阶段;物质来源及沉积环境参数,ααα20R甾烷百分含量C27>C28相似文献   

7.
江汉盐湖盆地中高成熟原油的地球化学特征及油源探讨   总被引:2,自引:0,他引:2  
江汉盐湖盆地中钟76井潜江组潜四段3300m以下发现的高成熟轻质原油,其基本特征是:饱和烃含量特高,非烃和沥青质含量很低;富含植烷、伽马蜡烷、C35升藿烷、孕甾烷和C27胆甾烷等指示高盐度、强还原环境的生物标志物。尤其明显的是C27-C29甾烷异构化程度高,αββ20R和20S峰十分突出,C29甾烷的两个参数值均大于等于0.5,指示了原油的成熟度已处于高成熟阶段。根据油源条件分析,认为该地区潜江组潜一段至潜四上段烃源岩埋深浅于3000m,P值小于1%,处于未成熟-成熟阶段,不具有形成高成熟原油的可能性,只有潜四下段烃源岩已进入生烃高峰高成熟早期阶段,能够提供轻质原油的油源。生物标志物多项地球化学资料及参数综合对比表明,本区两种成因类型的高成熟原油,其油源确系来自潜四下段两种不同沉积环境形成的泥质灰岩和灰质泥岩,明显具有近源运移聚集、自生、自储的特征,这展示了该地区潜四下段及其下覆的古潜山深层油气勘探有着良好的前景。  相似文献   

8.
柯克亚气田的油气成因复杂,对原油和可能烃源岩的分子标志物特征进行了剖析,在凝析油中检测到3-甲基甾烷,不含4-甲基甾烷,富含重排藿烷和C30^-未知萜烷.表明油源主要来自于二叠系源岩。柯克亚的天然气重烃含量高,属湿气,乙烷碳同位素偏重;天然气氩同位素和成熟度特征均指示混源气特征,通过气源判识天然气主要来源于石炭系一二叠系源岩,部分来源于侏罗系源岩。天然气的乙烷δ^13C值明显重于凝析油全油δ^13C值,揭示柯克亚地区凝析油和天然气分属不同来源。  相似文献   

9.
临南地区石油运移方向与成藏期次研究   总被引:11,自引:0,他引:11  
根据原油及油砂抽提物中含氮化合物分析、原油生物标志成熟度参数及储层流体包裹体烃类成分分析,研究了临南地区石油运移的方向、距离、成藏期次。结果表明临南油田仅有一期油气运聚成藏过程,属中新世末形成的成熟原油,4 甲基甾烷含量较高。曲堤油田存在两期油气运聚成藏过程,早期原油成熟度低,4 甲基甾烷含量低,运移距离较远,成藏后大部分散失 ;晚期充注的原油成熟度较高,4 甲基甾烷含量也较高,并保存至今。  相似文献   

10.
柯克亚气田的油气成因复杂,对原油和可能烃源岩的分子标志物特征进行了剖析,在凝析油中检测到3-甲基甾烷,不含4-甲基甾烷,富含重排藿烷和C30-未知萜烷,表明油源主要来自于二叠系源岩。柯克亚的天然气重烃含量高,属湿气,乙烷碳同位素偏重;天然气氩同位素和成熟度特征均指示混源气特征,通过气源判识天然气主要来源于石炭系—二叠系源岩,部分来源于侏罗系源岩。天然气的乙烷δ13C值明显重于凝析油全油δ13C值,揭示柯克亚地区凝析油和天然气分属不同来源。  相似文献   

11.
<正>So far there has been no common opinion on oil source of the Chepaizi swell in the Junggar Basin.Therefore,it is difficult to determine the pathway system and trend of hydrocarbon migration, and this resulted in difficulties in study of oil-gas accumulation patterns.In this paper,study of nitrogen compounds distribution in oils from Chepaizi was carried out in order to classify source rocks of oils stored in different reservoirs in the study area.Then,migration characteristics of oils from the same source were investigated by using nitrogen compounds parameters.The results of nitrogen compounds in a group of oil/oil sand samples from the same source indicate that the oils trapped in the Chepaizi swell experienced an obvious vertical migration.With increasing migration distance,amounts and indices of carbazoles have a regular changing pattern(in a fine linear relationship).By using nitrogen compounds techniques,the analyzed oil/oil sand samples of Chepaizi can be classified into two groups.One is the samples stored in reservoir beds of the Cretaceous and Tertiary,and these oils came from mainly Jurassic source rock with a small amount of Cretaceous rock;the other is those stored in the Jurassic,Permian and Carboniferous beds,and they originated from the Permian source.In addition,a sample of oil from an upper Jurassic reservoir(Well Ka 6), which was generated from Jurassic coal source rock,has a totally different nitrogen compound distribution from those of the above-mentioned two groups of samples,which were generated from mudstone sources.Because of influence from fractionation of oil migration,amounts and ratios of nitrogen compounds with different structures and polarities change regularly with increasing migrating distance,and as a result the samples with the same source follow a good linear relationship in content and ratio,while the oil samples of different sources have obviously different nitrogen compound distribution owing to different organic matter types of their source rocks.These conclusions of oil source study are identical with those obtained by other geochemical bio-markers. Therefore,nitrogen compounds are of great significance in oil type classification and oil/source correlation.  相似文献   

12.
Crude oil has been discovered in the Paleogene and Neogene units of the Weixinan Sag in the Beibu Gulf Basin. To determine the source and accumulation mode of this crude oil, 12 crude oil samples and 27 source rock samples were collected and an extensive organic geochemical analysis was conducted on them. Based on the geological conditions and the analytical results, the types, origins and accumulation patterns of crude oil in the study area were elucidated. Except for a shallowly-buried and biodegraded crude oil deposit in Neogene rocks, the crude oil samples in the study area were normal. All of the crude oils were derived from lacustrine source rocks. According to biomarker compositions, the crude oils could be divided into two families, A and B, distinctions that were reinforced by differences in carbon isotope composition and spatial distribution. Oil-source correlation analysis based on biomarkers revealed that Family A oils were derived from the mature oil shale at the bottom of the second member of the Liushagang Formation, while the Family B oils formed in the mature shale of the Liushagang Formation. The Family A oils, generated by oil shale, mainly migrated laterally along sand bodies and were then redistributed in adjacent reservoirs above and below the oil shale layer, as well as in shallow layers at high structural positions, occupying a wide distribution range. The Family B oils were generated by other shale units before migrating vertically along faults to form reservoirs nearby, resulting in a narrow distribution range.  相似文献   

13.
对黔东南凯里地区虎47井中奥陶统大湾组轻质原油及其附近露头的中下奥陶统大湾组和红花园组灰岩晶洞和裂缝中的残余油苗进行了色谱、色-质谱及碳同位素测试分析,根据其分子地球化学特征和有机质成熟度,进行了油源对比。结果表明:原油及油苗的干酪根均来源于藻类植物,形成于还原环境;甲基菲指数揭示原油呈成熟油特征,而油苗则呈高成熟油特征。经碳同位素对比(特别是单体烃同位素对比)认为,原油及油苗均是来源于本区下寒武统牛蹄塘组泥质烃源岩,但形成期次有所不同,为同源不同期的产物。  相似文献   

14.
Thirty one crude oil samples from Lower Cretaceous reservoirs in southern Iraq were analyzed using bulk property and molecular methods to determine their maturity and biomarker characteristics, as well as to obtain information on their respective source rocks. All the oils are unaltered, non-biodegraded, have high sulfur content and API gravity is in the range for light to heavy oil (19–40° API). They are characterized by low Pr/Ph values, even/odd predominance and front-end biased n-alkane distributions. Based on these parameters the oils were generated and expelled from a marine carbonate source rock bearing Type II-S kerogen. Compositional similarities of hopane and sterane biomarkers with those from potential source rocks allowed identification of the Upper Jurassic–Lower Cretaceous Sulaiy and Yamama carbonate succession as the effective source beds. A similar composition of normal and isoprenoid hydrocarbons among the oils suggests an origin from a common source rock. However, biomarker maturity ratios indicate a wide range of maturity. This appears to result from the type of burial history of the source rock, characterized by a slow passage through the liquid window interval during an extended period of geologic time.  相似文献   

15.
Sequential extraction was performed on two oil sandstones from the Upper Carboniferous oil columns of TZ401 well.The free oils of these two oil sandstones and a crude oil from the Lower Carboniferous oil column of this well have low ratios of C28/C27+C28+ C29) steranes and gammacerane/C31 hopanes,ranging of 0.11-0.16 and 0.09-0.15,respectively,similar to those from the Middle-Upper Ordovician source rock.However,these two ratios for the adsorbed and inclusion oils of these two oil sandstones are relatively high,ranging of 0.29-0.31 and 0.26-0.40,respectively,similar to those of the Cambrian-Lower Ordovician source rock.This result demonstrates that the initial oil charging the reservoirs was derived from the Cambrian-Lower Ordovician source rock,whereas the later charging oil was derived from the Middle--Upper Ordovician source rock.  相似文献   

16.
哈得逊与轮南地区原油碳同位素特征及影响因素   总被引:2,自引:0,他引:2  
轮南地区与哈得逊地区20个原油的全油碳同位素和正构烷烃单体烃碳同位素的分析结果表明:轮南地区原油的全油碳同位素均大于-32‰,而哈得逊地区原油的全油碳同位素一般小于-32‰;原油正构烷烃单体烃碳同位素也表现出轮南地区重于哈得逊地区的特征。两地区原油碳同位素的这种特征是由于两地区油气成藏过程的差异造成的,轮南地区原油碳同位素比哈得逊地区的原油碳同位素重的主要原因是由于来源于寒武系降解原油的混入,而非油源不同造成的。  相似文献   

17.
鄂尔多斯盆地董志—正宁地区是该盆地中生界油气勘探新区,对该地区原油的地球化学进行研究,了解原油的成因,可以为该地区石油勘探和开发提供科学依据。本研究首次对采集于董志—正宁地区原油和鄂尔多斯盆地烃源岩的烃类生物标志化合物进行了系统的分析,研究了它们的地球化学特征。原油中各类烃类生物标志化合物分布和组成特征指示了原油形成于...  相似文献   

18.
Geochemical composition characteristics of light oils from the Tertiary in the west of the Chepaizi uplift in the Junggar basin, northwest China, are distinct from those of biodegraded oils derived from the Permian in the study area and crude oils from some adjacent oil fields such as the Chepaizi and Xiaoguai oilfields. Oil source correlation shows that light oils in the study area have similar n-alkane and isoprenoid distribution patterns and carbon isotope compositions with the coal-derived oils from the Jurassic, and display obvious discrepancy on biomarker composition characteristics with the Cretaceous source rock extracts, inferring that they are probably the mixed oils from the Jurassic coal measures and Cretaceous source rocks. In this study, combined with the geochemical data of coal-derived oils from the Jurassic and Cretaceous source rocks or crude oils from the Cretaceous, the source and commingling features of the Tertiary crude oils of Well Pai 2 and Well Pai 8 were investigated. The proportion of the two sources in the mixed crude oils was estimated, and the hydrocarbon accumulation pattern of reservoirs in the study area was established.  相似文献   

19.
柴达木盆地原油地球化学特征及其源岩时代判识   总被引:10,自引:8,他引:10       下载免费PDF全文
在系统分析柴达木盆地北缘和西部各油田60余个原油样品轻烃、饱和烃和芳烃组成的基础上,全面揭示了两地区原油的标志性地球化学特征;并结合源岩分析资料,应用断代生物标志物建立了识别原油源岩时代的标志。研究结果表明,北缘各油田原油Mango轻烃参数K_1值波动在1.1上下,富含甲基环已烷和甲苯;正烷烃呈奇偶优势分布,姥鲛烷优势显著;反映侏罗系淡水湖沼相沉积有机质特征。西部原油K_1值大多在1.2以上,轻烃中富含异构支链化合物;正烷烃系列呈奇碳优势(C_(11)~C(17))和偶碳优势(C_(18)~C_(28))双重分布模式,强植烷优势;C_(28)甾烷相对含量高(>30%);脱羟基维生素E系列化合物丰富,5,7,8-三甲基-/8-甲基-MTTC比值大都低于10;表征古近系—新近系咸水湖相有机质性质。奥利烷和C_(26)降胆甾烷是区分侏罗系和古近系—新近系油源油的有效断代生物标志物。侏罗系原油无奥利烷,24-/(24-+27-)降胆甾烷比值小于0.25;古近系—新近系原油含有奥利烷,24-/(24-+27-)降胆甾烷比值高于0.6。  相似文献   

20.
海拉尔盆地贝尔凹陷油源及油气运移研究   总被引:20,自引:0,他引:20  
海拉尔盆地贝尔凹陷南屯组源岩有机质丰度高、类型好且已成熟,为本区的主要生油岩。大磨拐河组一段为次要生油岩。贝尔凹陷烃源岩灶主要分布在贝西洼陷和贝中的敖脑海洼陷中。油油对比显示出各构造带上的原油具有相似的生物标志化合物分布,表明来源于相同源岩。油岩对比指示原油主要来自于南屯组生油岩。苏德尔特构造带原油沿断裂带由西向东运移,呼和诺仁构造带原油由贝西洼陷北部源岩灶运移而来,纵向上原油显示出从下向上的运移特点。贝尔凹陷油气运移通道主要是断裂或不整合面,通源断裂两侧为油气勘探的有利部位。  相似文献   

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