典型海相油和煤成油饱和烃生物标志化合物特征研究

通过对塔里木盆地塔中隆起典型海相原油和吐哈盆地典型煤成油的饱和烃生物标志化合物系统剖析,对比分析了海相油与煤成油在饱和烃生标组合上的差异。海相油中Pr/Ph小于1,补身烷含量远高于升补身烷含量,三环萜烷含量丰富、富含C23、C24三萜化合物且C24四环萜烷含量较低,Ts/Tm较高、且伽马蜡烷含量明显高于煤成油,C27规则甾烷含量较高,而重排化合物含量较低。煤成油中Pr/Ph大于2.5,升补身烷含量高于补身烷含量,三环萜烷含量很低、富含C19、C20三萜化合物且C24四环萜烷含量较高,Ts/Tm很低、基本不含伽马蜡烷,C29规则甾烷含量相对较高;富含重排化合物。2类原油饱和烃生物标志化合物分布模式与组成特征揭示了其有机质的来源、类型、成熟度与沉积环境的差异。     

彩南油田多源混合原油的油源(二)——原油地球化学特征、分类与典型原油油源

根据准东地区各油田原油的碳同位素、生物标志化合物组成特征等，可将该地区原油分为5类：第一类原油的全油碳同位素值一般小于-30‰，Pr／Ph值一般小于2．0，富含β胡萝卜烷、三环萜烷、伽马蜡烷以及C28、C29甾烷，而C27甾烷含量很低、几乎不含重排甾烷，来源于二叠系烃源岩；第二类原油的全油碳同位素组成与第一类原油类似，但特别富含Ts、C29Ts和重排甾烷，而伽马蜡烷含量低，与三叠系烃源岩的亲缘关系很好；第三类原油的全油碳同位素明显重于第一、第二类原油，δ^13C值一般大于-28‰，且Pr／Ph值一般大干3．0，富含五环萜烷和C29甾烷，而三环萜烷、伽马蜡烷、C27和C28甾烷含量低，三环萜烷中以低碳数的C19、C20三环萜烷为主，来源于侏罗系烃源岩；第四类原油地球化学特征介于上述3类原油之间，与4套已知烃源岩均没有明确的油源关系；第五类原油碳同位素特别重，δ^13C值一般大于-25‰，与其它原油差异很大，来源于石炭系烃源岩。图4表1参28     

三塘湖盆地煤成油地球化学特征

依据生物标志物分布和组成特征,可把三塘湖盆地的原油和油显示分成中生界煤成油和上古生界湖相成因原油两大类,中生界煤成油以塘参1井中侏罗统西山窑组的原油为代表。表现为正构烷烃系列具明显的奇碳优势,Pr/Ph值高（＞4．0）,四环萜烷／三环萜烷＞1．0,三环萜烷系列中C19和C20相对丰度高于C21和C23,有C31六环藿烷,无伽玛蜡烷,C29甾烷占绝对优势,该原油源于中生界煤系源岩。上古生界湖相成因原油包括塘参3井,条2井和条3井油显示,其主要特征为正构烷烃系列没有明显的奇偶优势,Pr/Ph值低,三环萜烷／四环萜烷（仅检测到C24一个化合物）＞1．0,且C21和C23三环萜烷的相对丰度高于C19和C29,无C31六环藿烷,有较高含量的伽玛蜡烷和β－胡萝卜烷,C27甾烷丰度较高,它们源于该盆地上古生界湖相烃源岩。     

海拉尔盆地舒1井低蜡稠油成因及其意义

海拉尔盆地巴彦呼舒凹陷舒1井原油密度达0．932g／cm^3，但含蜡量仅为6％，属于低蜡稠油。原油中饱和烃含量仅30％左右，而非烃含量达30％以上；全油碳同位素组成很轻，δ^13C值分布为-34‰～-31‰；原油中类异戊二烯烷烃丰富，且以植烷占明显优势，Pr／Ph值小于0．9；甾烷组成中以ααα-20R构型甾烷为主，αββ构型异胆甾烷低，没有重排甾烷；萜烷组成以五环萜烷为主，三环萜烷含量低；含有丰富的伽马蜡烷和β-胡萝卜烷。原油的各种地球化学参数表明其属于低成熟原油，其成烃母质属于沉积于成水强还原环境的水生藻类有机质，是下白垩统南屯组烃源岩在低成熟阶段形成的产物。图4表1参8     

库车坳陷东部阳霞凹陷依南5井原油地球化学特征研究

依奇克里克油田位于库车坳陷东部阳霞凹陷的北部。通过对依南5井不同深度储层所产原油地球化学特征的系统分析发现,浅层原油的轻烃几乎不含苯系芳烃,其三环萜烷系列以C28为主峰,C24四环萜烷含量低,伽马蜡烷含量较高,甾炕系列中C27和C28甾烷含量高,重排甾烷含量较低,显示成水环境海相原油的特征。鉴于该原油中同时检测出了25-降藿烷系列,表明该原油是生物降解油与正常原油的混合油。而深部储层所产原油的轻烃中苯系芳烃丰富,三环萜烷以C19为主峰,C24四环萜烷含量极为丰富,伽马蜡烷含量极低,甾烷系列中C29甾烷占绝对优势,显示淡水湖沼相原油的特征。结合塔里木盆地不同成因类型原油的地球化学特征,推测依南5井不同深度所产原油存在这一差异的原因是浅层原油属于早期生物降解海相原油与晚期侏罗系湖沼相原油的混源油,而深部原油属于侏罗系烃源岩单一来源的原油。     

室内配比混源油地球化学特征研究

运用气相色谱、色谱-质谱和碳同位素等分析技术对准噶尔盆地典型的侏罗系和白垩系原油、二叠系和石炭系原油进行室内混源油配比实验分析,并对混源油的地球化学特征进行了研究,研究结果表明：混源油的碳同位素值与混源油的比例呈线性规律变化,侏罗系与白垩系混源油的姥植比随侏罗系原油比例增加而增大,三环萜烷C23／C19伽马蜡烷的含量随侏罗系原油比例的增加而减小。二叠系与石炭系混源油的姥植比随石炭系原油比例增加而增大,三环萜烷C23／C19、β－胡萝卜烷的含量随石炭系原油比例的增加而减小。图7参7     

江陵凹陷西南原油分子组成非均质性及其意义

对江陵凹陷西南区原油样品的地球化学分析表明,原油具有高丰度的伽马蜡烷及较低的Pr/Ph值,预示其来源于较强还原性的盐湖相沉积。原油分子组成非均质性预示两类不同成因类型原油的存在：Ⅰ类原油主要特征为相对较高C24-四环萜烷/C26三环萜烷比值和较低三环萜烷/藿烷、补身烷/藿烷、菲/藿烷、Ts/Tm比值;Ⅱ类原油其主要特征为相对较低C24-四环萜烷/C26-三环萜烷比值和较高三环萜烷/藿烷、补身烷/藿烷、菲/藿烷、Ts/Tm比值。两类原油区域性分布特征预示研究区区至少存在两套油气富聚体系。     

准噶尔盆地南缘西部山前断褶带油源分析

为了探讨准噶尔盆地南缘西部山前断褶带原油的油源问题，根据原油地球化学特征，将该区原油分为3类。第1类原油的全油碳同位素组成一般重于-27‰，Pr／Ph值大于2，规则甾烷中C29甾烷含量较高，具反“L”字型分布特征，伽马蜡烷／C30藿烷值通常小于0.1；第2类原油的全油碳同位素组成为-28‰～27‰，Pr／Ph值为1～2，规则甾烷呈“V”字型分布，伽马蜡烷／C30藿烷值为0．2～0．3；第3类原油的全油碳同位素组成为-30‰～-29‰，Pr／Ph值小于1，规则甾烷呈“V”字型分布，伽马蜡烷／C30藿烷值在0．5左右。油源对比分析认为，第1、第3类原油分别与侏罗系八道湾组煤系烃源岩和湖相烃源岩具有较好亲缘关系，而第2类原油可能主要来源于侏罗系三工河组或（和）西山窑组湖相烃源岩。图7表1参15     

东营凹陷王家岗地区原油成因类型及成藏特征分析

原油和烃源岩生物标志物分析表明,王家岗地区分布4种成因类型的原油:孔店型原油源于孔二段烃源岩,具有低密度、低硫、高蜡、饱和烃呈"单峰型"、胆甾烷C29＞C27＞C28呈反"L"型,成熟度较高、高三环萜烷含量等特征;沙四型原油源于沙四段烃源岩,高密度、高硫、低蜡、胆甾烷C27＞C29＞C28呈不对称"V"型、高伽马蜡烷含量,反映了咸水低等水生生物来源为主;混源型原油饱和烃分布呈"双峰型",来源于孔二段和沙四段烃源岩;南部埋藏较浅的圈闭中原油遭受生物降解等次生作用,正构烷烃缺失,为孔店组与沙四段的混源油或沙四型原油.由于烃源岩、运移通道和圈闭的配置差异,不同类型原油具有不同的成藏特征.     

鄂尔多斯盆地下寺湾油田原油地球化学特征及油源对比

根据饱和烃、同位素和甾萜类生物标志化合物的分析资料,全面剖析了下寺湾油田长3、长6油层原油的地球化学特征,并通过油源对比确定了其主力烃源层。研究结果表明,长3、长6油层原油为同一类型原油,饱和烃含量高,成熟度生物标志物参数达到平衡状态,表征原油未遭受明显生物降解作用,中等成熟度。原油碳同位素主要分布在-32.72‰^-32.05‰之间,族组分碳同位素分布规律:非烃>芳烃>原油≥饱和烃,各样品原油及其族组成碳同位素值相近,表现出一致的同源性。原油Pr/Ph值分布1.07-32.05‰之间,族组分碳同位素分布规律:非烃>芳烃>原油≥饱和烃,各样品原油及其族组成碳同位素值相近,表现出一致的同源性。原油Pr/Ph值分布1.07¹.21,C27-C29甾烷呈"V"型分布,伽马蜡烷含量较低,表征为淡水湖相沉积环境。通过油源对比并结合生储盖配套关系,揭示长3、长6原油为同一油源,并且为混源,长7烃源岩为主力油源。     

BIOMARKER GEOCHEMISTRY OF CRUDE OILS FROM THE QAIDAM BASIN, NW CHINA

A suite of 16 crude oil samples from 13 oilfields in the Qaidam Basin were analyzed using techniques including gas chromatography and gas chromatography - mass spectrometry. Biomarker compositions and parameters were used to investigate the palaeoenvironmental and depositional conditions and to correlate the oils with eachother. Oils from the western Qaidam Basin have pristane/phytane (Pr/Ph) ratios of less than 0.7, and contain abundant gammacerane, C₂₇ steranes, 4-methyl steranes and long-chain tricyclic terpanes. C₂₉ sterane 20S/(20S+20R) and ββ/(ββ+αα) ratios show that the western Qaidam oils have variable maturities ranging from immature to mature. Oils from the northern Qaidam Basin, by contrast, have Pr/Ph ratios greater than 3, low gammacerane contents, and relatively abundant C₂₉ steranes, bicyclic terpanes and alkylcyclohexanes. C₂₉ sterane 20S/(20S+20R) and ββ/(ββ+αα) ratios indicate that the northern Qaidam oils are mature.
δ¹³C values, which range from -25.4‰ to -28.3‰ with the exception of one oil from the north (-3l.6‰), are similar for oils from both the northern and western parts of the Qaidam Basin. The oils'carbon isotope compositions are similar to those of the organic matter in potential source rocks.
The western Qaidam oils are inferred to have originated from Tertiary source rocks deposited under anoxic and saline-hypersaline lacustrine conditions with dominant algal organic matter. The northern Qaidam oils are interpreted to be derived from Jurassic source rocks which were deposited in a freshwater lacustrine environment and which are dominated by terrigenous organic matter.     

GEOCHEMISTRY AND ORIGIN OF UPPER CRETACEOUS OILS FROM THE TERMIT BASIN,NIGER

Crude oil samples (n = 16) from Upper Cretaceous reservoir rocks together with cuttings samples of Upper Cretaceous and Paleogene mudstone source rocks (n = 12) from wells in the Termit Basin were characterized by a variety of biomarker parameters using GC and GC‐MS techniques. Organic geochemical analyses of source rock samples from the Upper Cretaceous Yogou Formation demonstrate poor to excellent hydrocarbon generation potential; the samples are characterized by Type II kerogen grading to mixed Types II–III and III kerogen. The oil samples have pristane/phytane (Pr/Ph) ratios ranging from 0.73 to 1.27, low C₂₂/C₂₁ and high C₂₄/C₂₃ tricyclic terpane ratios, and values of the gammacerane index (gammacerane/C₃₀hopane) of 0.29–0.49, suggesting derivation from carbonate‐poor source rocks deposited under suboxic to anoxic and moderate to high salinity conditions. Relatively high C₂₉ sterane concentrations with C₂₉/C₂₇ sterane ratios ranging from 2.18–3.93 and low values of the regular steranes/17α(H)‐hopanes ratio suggest that the oils were mainly derived from kerogen dominated by terrigenous higher plant material. Both aromatic maturity parameters (MPI‐1, MPI‐2 and R_c) and C₂₉ sterane parameters (20S/(20S+20R) and ββ/ (αα + ββ)) suggest that the oils are early‐mature to mature. Oil‐to‐oil correlations suggest that the Upper Cretaceous oils belongs to the same genetic family. Parameters including the Pr/Ph ratio, gammacerane index and C₂₆/C₂₅ tricyclic terpanes, and similar positions on a sterane ternary plot, suggest that the Upper Cretaceous oils originated from Upper Cretaceous source rocks rather than from Paleogene source rocks. The Yogou Formation can therefore be considered as an effective source rock.     

朝鲜安州盆地原油地球化学特征

安州盆地是朝鲜最大的中新生界陆相含油气沉积盆地.对始新统和下白垩统产层原油的有机地球化学研究表明:始新统原油具有煤成油的主要地化特征,源岩可能为如新统煤系地层;下白垩统原油具有湖相原油一般特征,与朝鲜湾盆地侏罗系原油及株罗系湖相源岩有一致性.安州盆地存在不同类型的油源岩和原油,具有一定的油气勘探远景.     

高青—平方王潜山带原油地化特征及油源分析

高青-平方王潜山带是东营凹陷盆缘潜山中勘探潜力最大的区带,研究区内油藏类型、油气来源比较复杂.文中运用原油地球化学特征的分析结果,对油气成因类型及油源进行了系统判识.研究表明,该区主要存在3类原油;Ⅰ型原油具有低Prh、高γ-蜡烷特点,与沙四上亚段烃源岩特征相近;Ⅱ型原油具有高Pr/Ph、低γ-蜡烷特点,表明原油与沙三...     

伊朗库姆盆地原油地球化学特征

伊朗库姆盆地已发现2类成熟原油:1)卡山区块原油类异戊二烯中植烷与姥鲛烷均势;萜烷中以C₃₀藿烷为主,含有较高的Ts、C₃₀重排霍烷,γ蜡烷较低;甾烷中重排甾烷含量高。厄尔布尔士油田原油类异戊二烯含量低、植烷优势明显;萜烷中Ts、C₃₀重排霍烷含量较低,γ蜡烷含量较高;甾烷中重排甾烷含量低。油—油对比表明,原油来自2套不同沉积环境的源岩,展示了伊朗库姆盆地内具有良好的烃源条件。      

塔里木盆地顺北地区白垩系原油成因类型与来源

塔里木盆地白垩系含油层系具有良好的勘探潜力,顺北地区在白垩系有较好的油气显示,测试获得少量原油。为研究顺北地区白垩系原油地球化学特征、成因类型、油气来源,系统开展了地球化学特征分析、油—油、油—源对比研究。顺北地区白垩系原油饱和烃色谱为单峰前峰型,正构烷烃系列保存完整,谱图基线平稳,未见明显的"鼓包",原油Pr/Ph分布在1.65~1.71,C21TT/C23TT>1,生标图谱中藿烷系列化合物占明显优势,∑三环萜烷/∑藿烷<1,检测到丰度较高的伽马蜡烷和三芳甾烷化合物,指示为保存条件良好的陆相成因类型原油;顺北白垩系原油与北部库车坳陷周缘的英买、大宛齐、大涝坝白垩系原油、库车河三叠系黄山街组泥质烃源岩具有较好的亲源性,指示油源来自库车坳陷三叠系黄山街组泥质烃源岩;白垩系原油热演化程度从大宛齐到英买再到顺北呈现出降低的趋势,推测顺北白垩系原油可能来源于库车坳陷三叠系烃源岩,生成的早期陆相油气沿白垩系优质砂体、T40不整合面、断裂由北向南远距离侧向运移。     

APPLICATION OF BIOMARKERS AND STABLE CARBON ISOTOPES TO ASSESS THE DEPOSITIONAL ENVIRONMENT OF SOURCE ROCKS AND THE MATURATION OF CRUDE OILS,EAST ZEIT FIELD,SOUTHERN GULF OF SUEZ,EGYPT

Four crude oil samples were collected from the producing wells EZ A-11, EZ A-1, EZ A-14 and EZ A-7 of East Zeit Field, offshore southern Gulf of Suez, Egypt. These crude oil samples represent the producing Kareem, Rudeis, Nukhul and Nubia reservoirs respectively. The crude oils were subjected to a variety of organic geochemical analyses including Gas Chromatography (GC), Gas Chromatography-Mass Spectrometry (GC-MS). In addition to stable carbon isotopes were done for the saturate and aromatic fractions and trace elements analysis. The organic geochemical results suggest the presence of two different types of oils that were originated from two different source environments. The Lower Miocene Kareem, Rudeis and Nukhul oils have a V/Ni ratios of 2, Ts/Tm ratio less than 1, Oleanane index of more than 20% and a gammacerane index of around 10%. Such results suggest that the Miocene crude oils were generated from an angiosperm-rich, Tertiary source rocks with high terrestrial input. The Nubian crude oil has a V/Ni ratio equal 3.2, Ts/Tm ratio less than 1, Oleanane index less than 20% and high gammacerane index of more than 30% suggesting a marine saline-source depositional environment of Late Cretceous or younger rich in type-II kerogen with minor terrestrial influence. The maturation parameters of the Miocene and Nubian crude oils obtained from aromatic and fraction imply marginally mature to mature oils. The Nubian crude oil however, was generated at a relatively higher maturation level than that of the Miocene oils. Also, the maturation level of the Miocene oils is in accordance with their relative stratigraphic position with the Nukhul reservoired oil being the most mature.     

APPLICATION OF BIOMARKERS AND STABLE CARBON ISOTOPES TO ASSESS THE DEPOSITIONAL ENVIRONMENT OF SOURCE ROCKS AND THE MATURATION OF CRUDE OILS, EAST ZEIT FIELD, SOUTHERN GULF OF SUEZ, EGYPT

Four crude oil samples were collected from the producing wells EZ A-11, EZ A-1, EZ A-14 and EZ A-7 of East Zeit Field, offshore southern Gulf of Suez, Egypt. These crude oil samples represent the producing Kareem, Rudeis, Nukhul and Nubia reservoirs respectively. The crude oils were subjected to a variety of organic geochemical analyses including Gas Chromatography (GC), Gas Chromatography-Mass Spectrometry (GC-MS). In addition to stable carbon isotopes were done for the saturate and aromatic fractions and trace elements analysis. The organic geochemical results suggest the presence of two different types of oils that were originated from two different source environments. The Lower Miocene Kareem, Rudeis and Nukhul oils have a V/Ni ratios of 2, Ts/Tm ratio less than 1, Oleanane index of more than 20% and a gammacerane index of around 10%. Such results suggest that the Miocene crude oils were generated from an angiosperm-rich, Tertiary source rocks with high terrestrial input. The Nubian crude oil has a V/Ni ratio equal 3.2, Ts/Tm ratio less than 1, Oleanane index less than 20% and high gammacerane index of more than 30% suggesting a marine saline-source depositional environment of Late Cretceous or younger rich in type-II kerogen with minor terrestrial influence. The maturation parameters of the Miocene and Nubian crude oils obtained from aromatic and fraction imply marginally mature to mature oils. The Nubian crude oil however, was generated at a relatively higher maturation level than that of the Miocene oils. Also, the maturation level of the Miocene oils is in accordance with their relative stratigraphic position with the Nukhul reservoired oil being the most mature.