【作者】 陈小慧；

【导师】 张敏；

【作者基本信息】 长江大学 ， 地球探测与信息技术， 2012， 博士

【摘要】 梨树断陷油气资源量丰富,但与松辽盆地其它断陷相比,油气成因和聚集成藏研究相对薄弱。本论文以梨树断陷深层烃源岩与油气为研究对象,综合利用现代有机地球化学分析方法和盆地模拟等技术,在烃源岩评价和烃源岩、原油、天然气地球化学研究基础上,深入探讨了梨树断陷深层油气成因与来源；通过系统剖析油藏烃类的非均质性、原油含氮化合物绝对浓度与相对比值以及生物标志化合物尤其是成熟度参数的变化特征,提出了梨树断陷油气运移方向、路径与聚集模式；开展了不同构造区代表性单井埋藏史研究,同时结合储层流体包裹体的详细研究以及地质构造和输导体系分布特征,明确了梨树断陷油气藏形成期次与成藏时间,研究成果为梨树断陷深层油气勘探提供了科学理论依据。对梨树断陷不同地区不同层位烃源岩进行了系统评价,指出烃源岩的空间展布特征。营城组和沙河子组烃源岩厚度大且有机质丰度高,登娄库组烃源岩次之。烃源岩以Ⅱ2-Ⅲ型有机质为主,洼陷带有机质类型优于斜坡带,大部分烃源岩处于成熟-高成熟阶段。平面上,桑树台洼陷带烃源岩沉积厚度最大且有机质丰度高,自南西-北东向,烃源岩厚度和有机碳含量逐渐减小；纵向上,营城组有机碳含量介于0.02%～12.01%之间,烃源岩最厚处位于孤家子地区,厚度为731m,双龙地区烃源岩厚度达200m,好-优质烃源岩分布于孤家子-十屋-后五家户一带,苏家屯次洼和双龙地区均发育一定的好-中等烃源岩,八屋部分地区主要为中等烃源岩,而秦家屯和北部斜坡地区基本无烃源岩分布；沙河子组有机碳含量范围为0.08%～7.42%,西南洼陷带烃源岩沉积厚度达900m,双龙地区源岩厚度达200m,皮家-十屋-孤家子-后五家户一带主要发育好-优质烃源岩,且秦家屯、双龙和苏家屯地区也分布有一定的好烃源岩；洼陷区登娄库组烃源岩厚度可达500m,有机碳含量为3.8%～5.5%,而双龙地区登娄库组烃源岩厚度达300m以上,有机碳含量均值为2.02%。根据生物标志化合物组合特征将研究区的烃源岩划分为三种类型：Ⅰ类源岩沉积于深湖-半深湖强还原微咸水-半咸水沉积相,以水生生物和陆源高等植物为母质来源,正构烷烃呈双峰态,三环萜烷/藿烷值在0.29-1.24之间,C24四环二萜/C26三环萜烷值为0.35～0.94, C27/C29aaa20R甾烷为0.58～1.18, Pr/Ph为0.29～0.70,伽马蜡烷/C30藿烷值为0.19～0.40；Ⅱ类源岩沉积于还原的半咸水-咸水环境,以高等植物输入为主,正构烷烃呈单峰,三环萜烷/藿烷值为0.75～1.97,C24四环二萜/C26三环萜烷比值较低,为0.24～0.29, aaa20R甾烷C27/C29为0.35～0.50, Pr/Ph为0.88-0.95,伽马蜡烷/C30藿烷值为1.14～2.77；Ⅲ类烃源岩沉积于弱还原-弱氧化的淡水-微咸水的滨浅湖环境,有机质以高等植物输入为主,正构烷烃呈后峰型,高碳数部分具有明显的奇碳优势,三环萜烷/藿烷值较低,为0.08～0.41,C24四环二萜/C26三环萜烷值0.98～5.34, C27/C29aaa20R甾烷比值为0.07～0.47, Pr/Ph为1.03～4.27,伽马蜡烷/C30藿烷值为0.06～0.27。梨树断陷原油划分为两种成因三种类型：Ⅰ类原油源于强还原微咸水-咸水环境条件,有机质以陆生高等植物为主,三环萜烷/藿烷为0.07～0.42,C24四环二萜/C26三环萜为0.41～1.29,C28和C29三环萜烷丰度较低,C29甾烷优势分布,伽马蜡烷/C30藿烷为0.16～0.60,C29降藿烷>C29Ts>C30重排藿烷,Ts≤Tm;Ⅱ类原油来源于还原的咸水环境,母源以陆生高等植物为主,三环萜烷/藿烷值较高,为0.43～4.17,C24四环二萜/C26三环萜值仅0.10～0.29,C28和C29三环萜烷丰富,C29规则甾烷丰度较高,伽马蜡烷/C30藿烷值为0.42～1.10,C29降藿烷<C29Ts<C30重排藿烷,Ts/Tm高达4.56～10.44；Ⅲ类原油生物标志化合物组合特征介于Ⅰ类原油与Ⅱ类原油之间,为Ⅰ类原油与Ⅱ类原油的混源油。精细油源对比结果表明,Ⅰ类原油与SN202井和SN18井营城组中下部烃源岩均具有C28和C29三环萜烷丰度较低,Ts与Tm相当,C30重排藿烷和伽马蜡烷丰度较低的共同特征；Ⅱ类原油与SN203井沙河子组中上部烃源岩均具有高丰度的C28和C29三环萜烷和C30重排藿烷以及伽马蜡烷等含量丰富的特征,混源油来源于上述两套烃源岩混合供烃。梨树断陷天然气为有机成因的混合气：①原油伴生气,主要分布于皮家、八屋等油气田；②不同成熟度的混合气,如苏家屯地区梨2井和四五家子地区W162井天然气可能为原油伴生气与原油裂解气的混合气；③孤家子、新立地区以及后五家户油气田HD20-18和HD26-17井天然气为煤成气与油型气的混合气。油型气主要源于断陷中心的营城组和沙河子组烃源岩,而煤成气主要来源于断陷中心的沙河子组煤系烃源岩。梨树断陷原油横向上主体沿西南-东北向向周缘斜坡区侧向运移,纵向上,沿断层向上垂向运移：Ⅰ类原油来源于西南深洼带营城组中下部源岩,沿断层、不整合面和连续砂体沿SW-NE向运移至断陷东北部；Ⅱ类原油源于西南深洼带沙河子组中上部烃源岩,向东北部运移。梨树断陷有登娄库期、泉头期和泉头末-嫩江期三期油气成藏。秦家屯地区登娄库组油气藏主要形成于泉头末期,营城组油气藏主要在泉头中期成藏,沙河子组油气藏主要在泉头早期成藏；八屋地区营城组油藏主要成藏期为泉头期,沙河子组油气藏成藏于登娄库末期和泉头期；北部斜坡营城组油气成藏期主要为泉头期；双龙地区登娄库组油气藏主要在泉头末-嫩江期成藏；后五家户地区登娄库组油气藏主要成藏期为泉头期,而营城组油藏主要在登娄库期聚集成藏。更多还原

【Abstract】 The hydrocarbon resources of Lishu fault depression are rich, but compared with other faulted basins in Songliao basin, the research on oil and gas origin and accumulation is relatively weak. By taking source rocks, oils and gases from deep strata in Lishu fault depression as research objects and integrating utilization of modern organic geochemistry analysis methods and basin model etc technologies, this paper made a further discussion on oil and gas origin on the basis of source rocks evaluation and the geochemical study on source rocks, crude oils and natural gases, through systematical analysis on heterogeneity in reservior hydrocabon and variation characteristics of absolute concentrations and relative ratios of nitrogen compouns and biomarkers especially maturity parameters, put forward the hydrocarbon migration direction and pathway and accumulation mode of Lishu fault depression; carried out study of the burial history of representative single wells in different tectonic regions, meanwhile combining detailed study of fluid inclusions in reserviors and the characteristics of geological structure and petroleum transportation system, explicated the formation stages and accumulation time of hydrocarbon reservoirs in Lishu fault depression, the research result provides a scientific theory basis for exploration of deep reservoirs in Lishu fault depression.The spatial extension characteristcs of source rocks is pointed out in this paper based on systematical evaluation of source rocks from different horizons and regions in Lishu fault depression. The source rocks from Yingchang and Shahezi formations have large thickness and high abundance of organic matter, and Denglouku formation followed by. The major organic matter types of source rocks are Ⅱ2-Ⅲ, the organic matter type of the source rocks in the sag zone is better than that of the slope zone, most source rocks are in mature-high mature stage. In horizontal direction, the thickness of the source rocks in Sangshutai sag is the most thick, and the organic matter content is high, from SW to NE, the thickness and the organic matter content of source rocks decrease gradually. In vertically, the organic matter content range of Yingcheng formation is from0.02%to12.01%, the most thick source rocks are in Gujiazi area, the thickness is731m, the thickness of source rocks in Shuanglong area is200m, good-high quality source rocks are distributed in Gujiazi-Shiwu-Houwujiahu region, and some middle-good quality source rocks are deposited in Sujiatun and Shuanglong areas, Bawu area mainly exists middle quality source rocks, but Qinjiatun area and the northern slope zone basically have no source rocks; the organic matter content of source rocks from Shahezi formation is between0.08%and7.42%, the deposited thickness of source rocks in southwest sag is900m, and the thickness in Shuanglong area is200m, Pijia-Shiwu-Gujiazi-Houwujiahu region exists goog-high qulity source rocks, and some good quality source rocks are deposited in Qinjiatun, Shuanglong and Sujiatun areas; the thickness of source rocks from Denglouku formation in the sag is up to500m, the TOC is3.8%～5.5%, and the thickness of source rocks from Denglouku formation in Shuanglong area is300m, and the mean TOC is2.02%.Based on the geochemical characteristics of biomarkers, source rocks of Lishu fault depression can be divided into three types:the Ⅰ kind of source rocks are from semi-deep to deep lake under strong reduction condition and brackish to semi-saline water, and aquatic organisms and terrigenous higher plants are the major source of organic matter, based on the following characteristics:biomodel state of n-alkanes, the ratio of tricyclic terpanes/hopane values from0.29to1.24, C24tetracyclic diterpane/C26tricyclic terpane ratios between0.35and0.94, high ratios of C27/C29ααα20R sterane (0.58～1.18), low Pr/Ph ratios (0.29～0.70) and gammacerane/C30hopane values between0.19and0.40; the Ⅱ kind of source rocks are believed to originate from semi-saline to saline water under reduction condition and terrigenous higher plants are the major organic matter origin on the basis of following features of biomarkers, n-alkanes are distributed in unimodality, tricyclic terpanes/hopane values are0.75～1.97, C24tetracyclic diterpane/C26tricyclic terpane values are low, between0.24and0.29, C27/C29aaa20R sterane values are0.35～0.50, Pr/Ph ratios are0.88～0.95, gammacerane/C3o hopane values are high, from1.14to2.77; the III kind of source rocks derived from shore-shallow lacustrine with fresh to brankish water and weak reducing to weak oxidizing environment, terrigenous higher plants are the dominated original source:n-alkanes appear a postpeak model and odd carbon number predominace in higher carbon number, tricyclic terpanes/hopane values are low, the range is from0.08to0.41, C24tetracyclic diterpane/C26tricyclic terpane values are high (0.98-5.34), C27/C29aaa20R sterane values are low, between0.07and0.47, Pr/Ph ratios are from1.03to4.27, and gammacerane/C3o hopane values are0.06～0.27.Crude oils from Lishu fault depression can be divided into two origins and three types:the I kind of crude oils are derived from strong reduction environment with brackish-saline water, and terrigenous higher plants are the major source of organic matter:tricyclic terpanes/hopane values range is from0.07to0.42, C24tetracyclic diterpane/C26tricyclic terpane values are0.41～1.29, and the abundance of C28and C29tricyclic terpanes is low, C29steranes are the dominant distribution in steranes, gammacerane/C3o hopane values are0.16～0.60, the abundance of C3odiahopane、C29TS and C29norhopanes increase gradually, and the relative content of Ts is less than Tm; the II kind of crude oils are originated from saline water under reduction condition, and the original source is mainly terrigenous higher plants:tricyclic terpanes/hopane values are high, between0.43and4.17, C24tetracyclic diterpane/C26tricyclic terpane values are low, from0.10to0.29, C28and C29tricyclic terpanes are abundant, C29regular steranes content is high, gammacerane/C3o hopane values are from0.42to1.10, and the abundance of C3odiahopane、C29TS and C29norhaopanes decrease gradually, Ts/Tm ratios are high, up to4.56to10.44; the Ⅲ kind of crude oils are the mixtures of Ⅰ and Ⅱ kinds of oils, the characteristics of biomarkers of the Ⅲ kind are between Ⅰ and Ⅱ kinds of oils.Detail oil and source correlation results show that the source rocks from the middle and lower part of Yingcheng formation in SN202and SN18wells and the Ⅰ kind of crude oils all possess the features of low abundance of C28and C29tricyclic terpanes, and similar abundance of Ts and Tm, and with relative low content of C3odiahopane、 C29Ts and gammacerane; the Ⅱ kind of crude oils and source rocks from the middle-upper part of Shahezi formation in SN203well all have the characteristics of high abundance of C28and C29tricyclic terpanes, and high Ts, C29Ts、C30diahopane and gammacerane; and mixed oils are supplied from these two sets of source rocks.The natural gases from Lishu fault depression are organic origin gases with mixed-gases characteristics:①oil-associated gases, are mainly distributed in Pijia,Bawu etc oil and gas fields;②mixtures from gases of different maturity, the gses from Li2well in Sujiatun area and the gases from W162well in Siwujiazi area are mixtures of oil-associated gases and oil cracking gases;③the gases from Gujiazi、Xinli areas and HD20-18and HD26-17wells in Houwujiahu oil and gas field are mixtures of oil type gases and coal formed gases. The oil type gases are mainly originated from Yingcheng and Shahezi formations in the center of the depression, and the coal-bearing source rocks of Shahezi formation in the center of subsidence are the major source of the coal formed gases.In the horizontal direction, the major transportation direction of crude oils in Lishu fault depression is laterally migrated from SW to NE towards periphery slope zones, in the longitudinal direction, migrated vertically along faults:the I kind of crude oils are orignated from the middle or lower-middle part source rocks of Yingcheng formation in the fault terrace zone in the southwest region, migrated from SW to NE along faults, unconformity surfaces and continuous sand bodies towards the northeast region of the depression; the Ⅱ kind of crude oils derived from the middle-upper part source rocks of Shahezi formation in the deep sag in the southwest region, migrated towards northeast region.The formation of hydrocarbon accumulation in Lishu fault depression had three stages:Denglouku formation period, Quantou formation period and the end of Quantou formation to Nenjiang formation. The oil reservoirs of Delouku formation in Qinjiatun area formed mainly in the end of Quantou formation period, and the oil and gas reservoir of Yingcheng formation accumulated mainly in the end of Quantou formation, and the hydrocarbon reserviors of Shahezi formation formed mainly in the early stage of Quantou formation; the major accumulation stage of the oil reserviors of Yingcheng formation of Bawu area is in Quantou formation period, hydrocarbon reserviors of Shahezi formation accumulated in the end of Denglouku formation and the Quantou formation period; the reservoir forming stage of Yingcheng formation in the northern slope zone is mainly in Quantou formation period; and the hydrocarbon reserviors of Denglouku formation in Shuanglong area are mainly formed in the end of Quantou formation to Nenjiang formation period; the main accumulation stage of the oil and gas reserviors of Denglouku formation in Houwujiahu area is Quantou formation period, and reserviors of Yingcheng formation accumulated mainly in Denglouku formation period.更多还原