东海西湖凹陷浙东中央背斜带烃源岩生排烃史研究

为了深化西湖凹陷浙东中央背斜带油气成藏过程的研究，优化勘探目标选择，在烃源岩特征分析的基础上，应用动态数值模拟技术，定量恢复了研究区主要烃源岩层系的生排烃历史，研究表明，浙东中央背斜带主要发育4套烃源岩系，其中始新统平湖组泥岩与煤层为主力烃源岩，具较高的有机质丰度=生烃强度与排烃效率，烃类排出具阶段性、多期次幕式排烃的特点汉平湖组为源岩的油气系统应是本区油气勘探的主要目标。     

东海陆架盆地丽水—椒江凹陷月桂峰组烃源岩特征及生排烃史

丽水—椒江凹陷是东海陆架盆地油气勘探的一个重要领域,目前处于较低的油气勘探阶段。基于现有地质资料,在烃源岩发育特征及有机质丰度、类型和成熟度分析的基础上,采用含油气盆地数值模拟技术,定量恢复了研究区月桂峰组烃源岩的生排烃史。结果表明,月桂峰组烃源岩有机质丰度高,有机质类型以Ⅱ1型和Ⅱ2型为主,具有油气兼生的能力,总体上处于成熟阶段和高成熟阶段;月桂峰组烃源岩具有较高的生排烃强度,总体上经历了2次生排烃过程,但在不同构造单元存在明显的差异性。总之,以月桂峰组烃源岩为油气来源的含油气系统是该区油气勘探的主要目标。     

南黄海古生界烃源特征及资源潜力评估

南黄海海域广泛分布了海相古生界,区域地质研究表明,南黄海海相古生界主要发育4套烃源岩层系,分别为下寒武统幕府山组泥质烃源岩,上奥陶统-下志留统五峰组-高家边组泥质烃源岩,下二叠统栖霞组灰质烃源岩和上二叠统龙潭-大隆组泥质烃源岩。通过对这4套烃源岩沉积特征及地球化学实验数据分析,开展了烃源岩地化特征和生烃潜力的评价。评价结果认为,下寒武统幕府山组、下二叠统栖霞组烃源岩有机质丰度高,类型好,生烃潜力高,为好-最好烃源岩;上二叠统龙潭组、大隆组烃源岩,其有机质丰度高,但有机质组成以陆源有机质为主,为较好烃源岩;奥陶-志留系为一般烃源岩,在此基础上,计算南黄海地区的天然气资源量为2.75万亿m~3。     

冀东油田南堡3号潜山烃源岩特征

通过综合运用有机地球化学方法,利用实测和收集到的烃源岩数据,对堡古2井的烃源岩进行分析,从有机质丰度、有机质成熟度、热解产率和排烃门限对区内烃源岩进行了评价,研究了该井的有机生烃特征,结果表明,南堡3号潜山发育丰富的烃源岩,有机碳含量高,有机质类型以Ⅱ1、Ⅱ2型为主,烃源岩已不同程度地进入成熟 高成熟阶段.综合分析表明,南堡3号潜山具备一定的生烃条件和油气勘探前景,可作为下一步的重要勘探和开发目标.     

东海丽水凹陷古新统非典型湖相烃源岩及油气特征

东海陆架盆地丽水凹陷主力烃源岩为古新统月桂峰组湖相泥岩,已发现油气以天然气为主,含少量凝析油,与以原油为主的中国东部典型断陷湖盆存在差异。对月桂峰组湖相泥岩进行了综合评价,发现其存在不能生烃的死碳,烃源岩的热演化成熟度与烃源岩形成石油的转化参数之间存在差异。月桂峰组有机质主要来源于陆源有机质,湖相水生生物来源的比例变化较大。烃源岩地球化学特征与典型湖相烃源岩存在差异。总结了湖盆类型对烃源岩的控制因素以及不同湖盆类型烃源岩形成油气的主要特征,并与月桂峰组湖相泥岩及已发现油气特征进行了对比,表明月桂峰组沉积期发育过补偿和平衡补偿湖盆。月桂峰组泥岩为非典型湖相烃源岩。     

中国近海断―坳转换期煤系烃源岩特征——以西湖凹陷平湖组烃源岩为例

西湖凹陷是东海陆架盆地最重要的含油气凹陷,古近系晚始新统平湖组烃源岩是西湖凹陷主力烃源岩,晚始新世平湖组沉积时期西湖凹陷处于断―坳转换时期,平湖组为一套海陆过渡相煤系地层,形成于半封闭海湾沉积环境。本文对断坳转换平湖组煤系烃源岩的分布、母质来源和生烃特征进行系统分析。结果表明:断—坳转换下的煤系烃源岩广覆式分布,平湖组煤系烃源岩富含反映干燥针叶类裸子植物来源的异海松烷和潮湿蕨类植物来源的β-扁植烷等二萜类化合物,从斜坡带向凹陷中央具有β-扁植烷增加的特征。从显微结构上表现为富含树脂体的煤系烃源岩,其具有"早期利于生油、晚期持续生气"的生烃模式。正是这种分布格局、母质来源和生烃特征决定了西湖凹陷油气藏具有"东气西油"的分布格局。     

南华北地区二叠系烃源岩分布及地化特征

南华北地区二叠系烃源岩主要发育于太原组、山西组、下石盒子组和上石盒子组,以煤系烃源岩为主.通过对各类烃源岩丰度、类型和成熟度的分析认为,煤系泥岩为主要的有效烃源岩,太原组、山西组和下石盒子组有机质丰度较高;母质类型以Ⅲ型(腐殖型)为主,也有少量Ⅱ2型(腐泥腐殖型);二叠系下统有机质处于过成熟-成熟阶段,中上统处于低成熟...     

渤海海域庙西北洼烃源岩特征与勘探潜力

利用最新的三维地震、钻井、测井、烃源岩和原油分析化验等资料,对庙西北洼烃源岩地球化学指标、分布特征及成因环境进行了分析,借助盆地模拟和油源对比结果,明确了庙西北洼的主力烃源岩层系和勘探潜力。研究认为:庙西北洼发育东营组和沙一二段2套烃源岩,其中沙一二段烃源岩有机质类型好、丰度高、有机质成熟度高,为好—很好烃源岩,其排烃量占洼陷总排烃量的56%,是庙西北洼的主力烃源岩。油源对比结果表明,PL15-2亿吨级大油田的原油来自沙一二段烃源岩,进一步佐证了沙一二段为主力烃源岩,也预示了庙西北洼具有良好的勘探潜力。     

地震属性法在南黄海北部盆地勘探新区烃源岩厚度预测中的应用

新区、深层和深水等低勘探程度地区是今后油气勘探的重要方向,而烃源岩厚度预测则是沉积盆地勘探新区烃源岩评价的重要问题。以南黄海北部盆地勘探新区东北凹陷的烃源岩早期评价为背景,基于地震反射特征追踪东北凹陷内烃源岩的发育层位和空间展布研究成果,首次应用地震属性方法对东北凹陷的主力烃源岩(上白垩统泰州组和古新统阜宁组)厚度进行了初步预测,并结合地震速度岩性分析法对本区泰州组烃源岩厚度的预测结果加以验证。结果表明南黄海盆地东北凹陷泰州组烃源岩较阜宁组烃源岩分布广且厚度大,西次洼为东北凹陷主力生烃洼陷。地震属性法是沉积盆地勘探新区内定量化预测烃源岩厚度的一种行之有效的新方法,其对于类似盆地勘探早期的烃源岩评价研究也具有非常重要的借鉴意义。     

西湖凹陷平北地区平湖组煤系烃源岩生烃潜力研究

西湖凹陷平北地区平湖组发育海陆过渡相的煤系烃源岩,以生烃潜力为主要依据对煤岩以及暗色泥岩的有机质丰度进行了评价,并建立了相应的评价标准,评价结果显示其有机质丰度均为中等―好,煤岩表现为S1+S2>90 mg/g,HI>100 mg/g,氯仿沥青"A">1.0%;暗色泥岩表现为TOC>1%, S₁+S₂>2 mg/g,氯仿沥青"A">0.05%,总烃"HC">150×10^-6。干酪根元素分析显示煤的干酪根类型主要为Ⅱ₁-Ⅱ₂型,富氢的显微组分含量较高,壳质组中的树脂体、孢子体及角质体含量达到10%～20%,且含有约20%的富氢镜质体,表明煤具有较高的生油潜力;暗色泥岩的富氢显微组分低于煤岩,有机质类型主要为Ⅱ2-Ⅲ型,以生气为主。根据镜质体反射率Ro以及S₁+S₂/TOC等指标共同确定了平北地区烃源岩的生烃门限(3 100 m)和排烃门限(3 500 m)。热模拟实验显示平湖组煤具有油气共生的特...     

珠江口盆地文昌A凹陷油气差异分布特征

在烃源岩分布特征、有机质丰度、类型和成熟度分析的基础上,运用含油气盆地数值模拟技术,定量恢复了烃源岩热成熟演化史,探讨了油气差异分布特征。研究表明,文昌A凹陷各层系烃源岩分布广,厚度大,有机质丰度高;有机质类型文昌组偏Ⅱ1型,恩平组偏Ⅲ型,二者现今多处于高成熟—过成熟阶段。凹陷内烃源岩成熟时间早(文昌组约45.5Ma),现今成熟度高,以干气生成为主;凹陷边缘烃源岩成熟时间较晚(文昌组约30.0Ma),现今成熟度相对较低,以石油生成为主。凹陷现今油气差异分布的格局受制于有机质类型差异和热演化史不同,且下一步油气勘探方向,凹陷内以天然气为主,凹陷边缘以石油为主。     

民和盆地侏罗系生烃潜力与油气勘探方向

从有机碳含量、可溶有机质含量及其转化率、热解参数、饱和烃的生物表示化合物特征、有机岩石学特征几个方面分析了民和盆地侏罗系烃源岩的有机质丰度、类型和成熟度,并进行了地球化学特征分析和生烃潜力评价。分析认为盆地发育湖相泥岩和煤系两大类烃源岩,有机质以较富含低等水生生物原始母质的腐泥腐殖型为主,主要分布于中侏罗统。通过对盆地石油地质条件的评价,结合各区带落实认识程度和资料品质条件认为：武家鼻隆构造带是最有利的勘探区带,万泉堡鼻状构造带具有良好勘探潜力,大庄构造带是寻找浅层次生油气藏的有利区带。永登凹陷面积大,资源丰富,勘探认识程度低,具有良好勘探前景。     

Basin modeling of the Late Miocene Zeit source rock in the Sudanese portion of Red Sea Basin: Implication for hydrocarbon generation and expulsion history

The Late Miocene Zeit Formation is exposed in the Red Sea Basin of Sudan and represents an important oil-source rock. In this study, five (5) exploratory wells along Red Sea Basin of Sudan are used to model the petroleum generation and expulsion history of the Zeit Formation. Burial/thermal models illustrate that the Red Sea is an extensional rift basin and initially developed during the Late Eocene to Oligocene. Heat flow models show that the present-day heat flow values in the area are between 60 and 109 mW/m². The variation in values of the heat flow can be linked to the raise in the geothermal gradient from margins of the basin towards offshore basin. The offshore basin is an axial area with thick burial depth, which is the principal heat flow source.The paleo-heat flow values of the basin are approximately from 95 to 260 mW/m², increased from Oligocene to Early Pliocene and then decreased exponentially prior to Late Pliocene. This high paleo-heat flow had a considerable effect on the source rock maturation and cooking of the organic matter. The maturity history models indicate that the Zeit Formation source rock passed the late oil-window and converted the oil generated to gas during the Late Miocene.The basin models also indicate that the petroleum was expelled from the Zeit source rock during the Late Miocene (>7 Ma) and it continues to present-day, with transformation ratio of more than 50%. Therefore, the Zeit Formation acts as an effective source rock where significant amounts of petroleum are expected to be generated in the Red Sea Basin.     

Petroleum retention in the Mandal Formation,Central Graben,Norway

Upper Jurassic organic matter-rich, marine shales of the Mandal Formation have charged major petroleum accumulations in the North Sea Central Graben including the giant Ekofisk field which straddles the graben axis. Recent exploration of marginal basin positions such as the Mandal High area or the Søgne Basin has been less successful, raising the question as to whether charging is an issue, possibly related to high thermal stability of the source organic matter or delayed expulsion from source to carrier.The Mandal Formation is in part a very prolific source rock containing mainly Type II organic matter with <12 wt.-% TOC and HI < 645 mg HC/g TOC but Type III-influenced organofacies are also present. The formation is therefore to varying degrees heterogeneous. Here we show, using geochemical mass balance modelling, that the petroleum expulsion efficiency of the Mandal Formation is relatively low as compared to the Upper Jurassic Draupne Formation, the major source rock in the Viking Graben system. Using maturity series of different initial source quality from structurally distinct regions and encompassing depositional environments from proximal to distal facies, we have examined the relationship between free hydrocarbon retention and organic matter structure. The aromaticity of the original and matured petroleum precursors in the Mandal source rock plays a major role in its gas retention capacity as cross-linked monoaromatic rings act on the outer surface of kerogen as sorptive sites. However, oil retention is a function of both kerogen and involatile bitumen compositions. Slight variations in total petroleum retention capacities within the same kerogen yields suggest that texture of organic matter (e.g. organic porosity) could play a role as well.     

华北中新元古界海相碳酸盐岩烃源岩评价

Marine carbonate rocks are widespread and their sedimentary layers are huge and thick.Many oil seepages outcrops are found in the Middle-Upper Proterozoic of North China. Combined with previous data, the paper discusses the evaluation criteria of marine carbonate source rocks.Many factors,such as organic matter types of source rocks,thermal maturity,mineral and chemical composition,paleotemperature and source-reservioir relationship etc. Should be considered. Therefore,the abundance cutoff criteria of organic matters in North China especially in the Southern area,needs further.In this paper,North China is divided into the north area dn the south area,and the organic matter type,organic matter abundance and degree of thermal evolution of organic matter in the two areas in overall and both of them are high thermal evaluation level.Furthermore,the majority of the organic matters of the source rock have been in highly over matured phase.Source rock mature period of Liulaobei Formation and Xuhuai Group in the southern area ids equal to that of the lower Xiamalin Formation in the northern area,the hydrocarbon generation capacity of Chuanlinggou Formation,and different organic matter types obtained with different methods on source rock research in the south area of North China are also put forward.     

西湖凹陷中-下始新统宝石组油气地质与勘探潜力

西湖凹陷是东海陆架盆地油气勘探潜力最好的凹陷之一。通过西湖凹陷宝石一井中下始新统宝石组井震资料,厘定了影响油气资源计算结果较大的关键参数,如烃源岩厚度、有机质油气产率、排聚系数等;建立了构造、沉积、孔隙度与油气生、运、聚模型,编绘了西湖凹陷宝石组生油岩厚度图、有机碳、Ro、生油气强度等值线图;采用BASIMS 4．5盆地综合模拟系统重现了西湖凹陷宝石组的地史、热史、生烃史、排烃史和运聚史,分析了宝石组空间展布特征与生、储、盖、圈、运、保等地质条件,提出并建立了宝石组合油气系统。利用多种方法定量计算的宝石组生烃量和资源量与西湖凹陷已证实的主力烃源岩系平湖组相似,认为宝石组是西湖凹陷又一重要烃源岩及油气勘探目的层系,拥有巨大的油气勘探潜力。     

Quantitative modelling of hydrocarbon expulsion and quality grading of tight oil lacustrine source rocks: Case study of Qingshankou 1 member,central depression,Southern Songliao Basin,China

The quality of source rocks plays an important role in the distribution of tight and conventional oil and gas resources. Despite voluminous studies on source rock hydrocarbon generation, expulsion and overpressure, a quality grading system based on hydrocarbon expulsion capacity is yet to be explored. Such a grading system is expected to be instrumental for tight oil and gas exploration and sweet spot prediction. This study tackles the problem by examining Late Cretaceous, lacustrine source rocks of the Qingshankou 1 Member in the southern Songliao Basin, China. By evaluating generated and residual hydrocarbon amounts of the source rock, the extent of hydrocarbon expulsion is modelled through a mass balance method. The overpressure is estimated using Petromod software. Through correlation between the hydrocarbon expulsion and source rock evaluation parameters [total organic carbon (TOC), kerogen type, vitrinite reflectance (R_o) and overpressure], three classes of high-quality, effective and ineffective source rocks are established. High-quality class contains TOC >2%, type-I kerogen, R_o >1.0%, overpressure >7Mpa, sharp increase of hydrocarbon expulsion along with increasing TOC and overpressure, and high expulsion value at R_o >1%. Source rocks with TOC and R_o <0.8%, type-II₂ & III kerogen, overpressure <3Mpa, and low hydrocarbon expulsion volume are considered ineffective. Rocks with parameters between the two are considered effective. The high-quality class shows a strong empirical control on the distribution of tight oil in the Songliao Basin. This is followed by the effective source rock class. The ineffective class has no measurable contribution to the tight oil reserves. Because the hydrocarbon expulsion efficiency of source rocks is controlled by many factors, the lower limits of the evaluation parameters in different basins may vary. However, the classification method of tight source rocks proposed in this paper should be widely applicable.     

New perspective of Miocene marine hydrocarbon source rocks in deep-water area in Qiongdongnan Basin of northern South China Sea

Drilling wells reveal that the organic matter abundance of Miocene marine source rocks in shallow water area of the Qiongdongnan Basin is relatively low with poor hydrocarbon generation poten- tial. However, in some drilling wells of deep water area close to the central depression belt, Miocene marine source rocks with better organic matter abundance and hydrocarbon generation have been found, which have achieved better source rock standard based on the analysis of geochemical charac- teristics. Although there are no exploratory wells in deep water area of the research region, through the comparative analysis of geochemical data of several typical exploratory wells respectively from shallow water area in the basin, central depression belt margin in deep-water area of the basin and Site 1148 of deep sea drilling in the South China Sea Basin, it reveals that the tendency of the quality of source rocks becomes positive gradually from delta to bathyal environment, which then becomes negative as in deep oceanic environment. Owing to the lack of terrestrial organic matter input, the important controlling factors of Miocene marine source rocks in the Qiongdongnan Basin are ocean productivity and preservation conditions of organic matter. The element geochemistry data indicate that the tendency of the paleoproductivity and the preservation conditions of organic matter become positive as water depth increase from shallow area to bathyal area close to central depression belt. So it is speculated that there must exist high quality source rocks in the central depression area where the preservation conditions of organic matter are much better. Besides, in theory, in oxygen-poor zone of oceanic environment at the water depth 400-1 000 m, the preservation conditions of organic matter are well thus forming high-quality marine source rocks. The result- ing speculation, it is reasonable to consider that there are high hydrocarbon generation potential source rocks in bathyal environment of the Qiongdongnan Basin, especially at the water depth 400- 1 000 m.