鄂尔多斯盆地伊盟隆起上古生界烃源岩地球化学特征

烃源岩是石油和天然气生成的物质基础,决定了勘探区块的潜在资源量,具有重要的研究价值。对鄂尔多斯盆地伊盟隆起上古生界烃源岩进行岩性、厚度以及地球化学分析,结果表明:上古生界烃源岩岩性主要为泥岩、炭质泥岩和煤层,上古生界暗色泥岩总厚度一般为10~50 m;平面上具有南厚北薄、东厚西薄、局部发育的特征;太原组和山西组炭质泥岩和煤层有机质丰度较高;干酪根以Ⅲ型为主,其次为Ⅱ型;原始有机质形成于弱氧化环境;上古生界烃源岩Ro值介于0.6%~1.8%之间,已经进入成熟-高成熟阶段,且南部生气强度大。其研究结果可以为伊盟隆起区上古生界的油气资源评估提供依据。     

鄂尔多斯盆地伊盟隆起上古生界储层孔隙结构特征及评价

储层是油气赋存的载体,其孔渗性能决定着后期油气开采难度以及可采数量。在众多影响储层孔渗性能的因素当中,储集层的孔隙结构发挥了关键的作用。通过对鄂尔多斯盆地伊盟隆起上古生界储层岩性以及孔渗参数进行分析,结果表明：石盒子组孔喉连通性及渗流性能最好,其次是山西组,太原组最差;依据压汞资料和毛细管压力曲线形态,孔隙结构类型可以划分为4类;通过孔渗资料统计分析,上古生界砂岩划分4类,并以Ⅱ类和Ⅲ类储层为主;砂体主要为冲积扇辫状水道砂体,曲流河、辫状河河道砂坝砂体以及三角洲平原分流河道砂体。研究结果可以为伊盟隆起区上古生界的油气开发提供依据。     

鄂尔多斯盆地上古生界地层AVO技术的应用

AVO技术是利用振幅随炮检距 (或入射角 )变化的规律 ,求取地下地层的岩性信息。鄂尔多斯盆地是典型克拉通盆地 ,构造平缓 (倾角不到 1°) ,断层不发育 ,非常适用 AVO理论假设反射层为水平层这一基本条件。根据工区的地震地质特征 ,在 AVO分析的基础上 ,应用钻井地质、测井资料设计的模型 AVO正演及反演的研究 ,总结了一套在现有地震分辨率条件下的鄂尔多斯盆地上古生界储层 AVO响应特征。即 :无论砂岩储层是否含气 ,其底部反射振幅随入射角增加均会出现从强到弱—极性反转—从弱到强的现象 ,只是反转的角度有所差异 ;在梯度剖面上 ,含气砂岩与不含气砂岩的亮点特征差异较大。据此响应特征预测了有利的储集区。     

鄂尔多斯盆地伊盟隆起上古生界储层孔隙结构特征及评价CSCD

储层是油气赋存的载体,其孔渗性能决定着后期油气开采难度以及可采数量。在众多影响储层孔渗性能的因素当中,储集层的孔隙结构发挥了关键的作用。通过对鄂尔多斯盆地伊盟隆起上古生界储层岩性以及孔渗参数进行分析,结果表明:石盒子组孔喉连通性及渗流性能最好,其次是山西组,太原组最差;依据压汞资料和毛细管压力曲线形态,孔隙结构类型可以划分为4类;通过孔渗资料统计分析,上古生界砂岩划分4类,并以Ⅱ类和Ⅲ类储层为主;砂体主要为冲积扇辫状水道砂体,曲流河、辫状河河道砂坝砂体以及三角洲平原分流河道砂体。研究结果可以为伊盟隆起区上古生界的油气开发提供依据。     

鹿邑凹陷古生界烃源岩热演化

鹿邑凹陷位于周口坳陷北部凹陷带东端,以Ro为古温标的周参7井和周参8井热史恢复结果表明,鹿邑凹陷古生代为克拉通台地阶段,基底热流值较低(40~50 mW/m2),剥蚀厚度小;印支—燕山期构造活动强烈,基底热流值升高到83 mW/m2,剥蚀厚度1 000~2 000 m左右;喜山期至今基地热流值降低到49 mW/m2,盆地冷却。鹿邑凹陷主要有中奥陶统和二叠等4套烃源岩,主要生烃期为早中三叠世,印支燕山期生烃停滞,喜山期以生气为主。     

西湖凹陷平北地区烃源岩特征及生排烃史

为了综合确定平北地区的主力烃源岩,深化其油气成藏动力学过程研究,在烃源岩分布特征及有机质丰度、类型和成熟度分析的基础上,应用舍油气盆地数值模拟技术,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,平北地区主要发育始新统平湖组、渐新统花港组两套烃源岩系,其中平湖组暗色泥岩为主力烃源岩,具较高的有机质丰度、成熟度、生排烃强度与排烃效率;以平湖组为源岩的油气系统应是本区油气勘探的主要目标。     

北部湾盆地涠西南凹陷C洼烃源岩热史及成熟史模拟

北部湾盆地涠西南凹陷C洼流沙港组烃源岩热史及成熟史研究,对C洼深水油气勘探具有指导意义。在恢复涠西南凹陷C洼地史和热史的基础上,利用EASY%Ro模型计算了流沙港组烃源岩的成熟度史。研究结果表明,在涠西南凹陷发展的裂陷阶段初始期热流值较高,最大值约为77mW/m2,其后热流值逐渐减小,现今热流值约为54mW/m2;涠西南凹陷C洼流沙港组烃源岩开始生烃(Ro=0.5%)时间为51MaBP,达到生烃高峰(Ro=1%)时间为42MaBP,达到高成熟演化阶段(Ro=1.3%)时间为17MaBP;对比涠1井流沙港组烃源岩演化特征,处于C洼深水勘探区的流沙港组烃源岩成熟度较高,生烃能力较强,拥有广阔的油气勘探前景。     

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。     

南黄海盆地阜宁组烃源岩地层热压生烃特征

通过生烃模拟获取生烃动力学参数是近年来油气资源评价工作中极为重要的一个环节,利用地层热压生排烃模拟装置对南黄海盆地南二凹陷阜四段烃源岩进行了生烃模拟实验,并拟合了生烃动力学参数。实验及研究结果表明,阜四段烃源岩的生烃演化可分为3个阶段：第1阶段产烃量随温度上升快速增大,以产油为主;第2阶段产烃量随温度上升缓慢增加,为油、气同产;第3阶段产烃量随温度上升快速增大,主要是以生气为主。实验拟合出阜四段烃源岩的生油活化能为228 kJ/mol,生气活化能为280 kJ/mol。与常压—完全开放体系试验、金管-高压釜实验装置的实验结果对比,本次实验南黄海盆地阜四段烃源岩在地层热压条件下出现生油窗滞后现象,烃源岩样品在高成熟演化阶段依然具有较高的液态烃产率。阜四段生油活化能值较高,其内在原因是有机质受到烃源岩孔隙中高压水的“保护”作用以及受生烃空间的影响,延缓了烃源岩的热演化进程。综合前人实验结果分析,有限空间热压生烃模拟实验环境更接近于烃源岩在地层条件下的生烃条件,实验结果对南黄海盆地的油气资源潜力评价及油气勘探方向具有指导意义。     

鄂尔多斯盆地彭阳地区延长组、延安组原油地球化学特征与油源对比

鄂尔多斯盆地彭阳地区的中生界延长组、延安组油源还存在一定的不确定性,应用分子地球化学的手段和方法,对彭阳地区延长组、延安组的原油及长7烃源岩样品和盆地内部长7优质烃源岩样品开展生物标识化合物地球化学定量分析,并进行油源对比研究。结果表明：鄂尔多斯盆地天环坳陷彭阳地区延长组、延安组原油形成于淡水、微咸水且还原性较强的环境;生物标志化合物地球化学特征相似,属于同一成因类型,具有相同的油源;原油母质类型为低等水生生物和陆生高等植物构成的混合型母质,原油已经成熟。彭阳地区原油在成熟度、母源性质和沉积环境方面与盆地内部长7优质烃源岩具有相似的特征,二者具有较好的亲缘关系,彭阳地区原油不是本地长7泥岩产物,主要来自盆地内部长7优质烃源岩。     

太康隆起上古生界稀土元素地球化学特征及其地质意义

南华北盆地晚古生代海陆交互相暗色泥岩较为发育,是该区主要烃源岩层系之一。本文采用电感耦合等离子体质谱仪和X射线荧光光谱（XRF）对太康隆起西部地区上古生界本溪组、太原组、山西组和下石盒子组28件暗色泥岩、粉砂质泥岩样品进行了稀土元素和微量元素测试,基于稀土元素的稳定性和其对沉积水体变化的高敏感度,结合泥岩有机碳含量及宏观沉积特征,探讨太原组、山西组古沉积环境及其对有机质富集的影响。分析结果表明,太康隆起地区太原组和山西组稀土元素总量高,轻、重稀土元素分异程度相近,明显高于本溪组和下石盒子组,同时山西组具有较弱的Ce负异常和较强的Eu负异常。Ce异常表明本溪组至下石盒子组整体形成于缺氧的还原环境。ΣREE和TOC在垂向上的变化表明古气候条件经历了由干冷向温湿的转变,沉积速率先降低再增大,太原期沉积水体深,沉降速率低,环境稳定,对有机质的富集和保存有着重要的地质意义。     

莺歌海盆地中新统海相烃源岩有机相特征

为了实现莺歌海盆地中新统海相烃源岩的精细划分与评价,结合地球化学测试资料,对莺歌海盆地中新统烃源岩进行有机相划分,建立了有机相与沉积相的对应关系,进而预测烃源岩的平面展布。研究结果表明,按照有机质来源与沉积环境可将莺歌海盆地中新统海相烃源岩分为4类：海相陆源型、海相混源Ⅰ型、海相混源Ⅱ型、海相内源型。不同有机相与沉积相对应关系较好,其中,扇三角洲、滨海相对应海相陆源型,内浅海对应海相混源Ⅰ型,外浅海、半深海对应海相混源Ⅱ型,外浅海、半深海和深海对应海相内源型。海相混源Ⅱ型烃源岩分布广,厚度大,有机质丰度较高,有机质类型以Ⅱ2型干酪根为主,少量Ⅲ型干酪根,保存条件较好,是莺歌海盆地的主要气源岩。研究成果为预测莺歌海盆地中新统海相优质烃源岩的平面展布并准确评价其资源潜力提供了重要依据。     

东海陆架盆地丽水凹陷热演化模拟及现今地温场特征

东海陆架盆地丽水凹陷烃源岩埋深大、钻井少、油气发现少,至今对其生油气能力具有较大的争议。为明确烃源岩热演化史,从少量具备实测地层温度和镜质体反射率（Ro）资料的钻井出发,利用正演模拟方法,通过地温与地层深度相关性分析,将钻井地温研究结果外推到无井区。在恢复丽水凹陷探井岩石圈结构及其演化史的基础上,首次系统建立了丽水凹陷的区域地温场并分析其对烃源岩演化的作用。研究表明,古新统下段月桂峰组底界（T100）烃源岩大部分都已成熟,次洼中心局部过成熟;月桂峰组顶界（T90）烃源岩大部分处于低熟—成熟阶段,次洼中心局部高—过成熟;灵峰组顶界（T85）烃源岩处于未熟—低熟状态,西次洼中心有成熟烃源岩。烃源岩特征及演化分析表明,古新统下段月桂峰组烃源岩是丽水凹陷的主力生油气烃源岩。     

琼东南盆地深水区烃源岩生烃动力学及生气模式

In order to investigate the hydrocarbon generation process and gas potentials of source rocks in deepwater area of the Qiongdongnan Basin, kinetic parameters of gas generation(activation energy distribution and frequency factor) of the Yacheng Formation source rocks(coal and neritic mudstones) was determined by thermal simulation experiments in the closed system and the specific KINETICS Software. The results show that the activation energy(Ea) distribution of C1–C5 generation ranges from 50 to 74 kcal/mol with a frequency factor of 2.4×1015 s–1 for the neritic mudstone and the Ea distribution of C1–C5 generation ranges from 49 to 73 kcal/mol with a frequency factor of 8.92×1013 s–1 for the coal. On the basis of these kinetic parameters and combined with the data of sedimentary burial and paleothermal histories, the gas generation model of the Yacheng Formation source rocks closer to geological condition was worked out, indicating its main gas generation stage at Ro(vitrinite reflectance) of 1.25%–2.8%. Meanwhile, the gas generation process of the source rocks of different structural locations(central part, southern slope and south low uplift) in the Lingshui Sag was simulated. Among them, the gas generation of the Yacheng Formation source rocks in the central part and the southern slope of the sag entered the main gas window at 10 and 5 Ma respectively and the peak gas generation in the southern slope occurred at 3 Ma. The very late peak gas generation and the relatively large gas potential indices(GPI:20×108–60×108 m3/km2) would provide favorable conditions for the accumulation of large natural gas reserves in the deepwater area.     

Petrology and depositional evolution of the Paleozoic rocks of Iraq

The study integrates petrographical and lithological data from deep exploration wells and outcrops in northern Iraq to better understand the sedimentary environments present in the basin and to evaluate the depositional evolution of the Paleozoic rocks in Iraq. The studied Paleozoic successions are represented by five sedimentary cycles of intracratonic sequences. These are dominated mainly by siliciclastic and mixed sedimentary packages, and are separated by major and minor unconformity surfaces. These cycles are as follow: the Ordovician cycle, represented by the Khabour Formation; the Silurian cycle, represented by the Akkas Formation; the Middle-Late Devonian to Early Carboniferous cycle, represented by the Chalki, Pirispiki, Kaista, Ora and Harur formations; the Permian–Carboniferous cycle, represented by the Ga’ara Formation and late Permian cycle, represented by the Chia Zairi Formation. Generally, the cycles are characterized by siliciclastic and mixed carbonate–clastic facies with abrupt changes during Late Paleozoic reflecting the environmental and tectonic events during this period. The Ordovician Khabour Formation is suggested to be of shallow marine environment of deposition with stacked transgressive and regressive cycles that are eustatically controlled. The shale of Silurian Akkas Formation was deposited in open-marine environment. Depositional regimes in the Late Devonian to Early Carboniferous are considered as a continuation of deposition in the subsiding basin with a wide geographic distribution that reflect the epicontinental or epeiric seas in a homoclinic ramp setting. The Permo-Carboniferous Ga’ara Formation was deposited in continental to paralic environment while the Late Permian Chia Zairi Formation represents the carbonate platform deposition. The study revealed that potential source rocks may include some shale beds of the Khabour Formation, hot shales of Akkas Formation and the shales of Ora Formation. The sandstones of the Khabour, Akkas and Kaista formations have good reservoir potential. The Late Permian carbonates of Chia Zairi Formation may be self-sourcing and contain multiple reservoirs. The occurrence of shale as source rocks and limestone as reservoir rocks and some evaporates as sealing horizons make the formation as a reservoir in its own right.     

Thermal history and source rock characterization of a Paleozoic section in the Awbari Trough,Murzuq Basin,SW Libya

In some areas of the Murzuq Basin, SW Libya, the lower Silurian member comprises highly radioactive shales (Hot Shale), which are regarded as the most significant factor controlling petroleum generation in the basin. In this context, it was the goal of our project to study the distribution and maturity of the Hot Shale in the framework of basin evolution. Organic geochemical, organic petrological and basin modelling methods were used to obtain a more thorough understanding. Four wells from the northern and central part of the Awbari Trough have been selected for this study.     

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。     

The effective source rocks in the north Cambay Basin, India

Source rock screening reveals five laterally extending potential sources (PS) in the Paleogene. The PSs are SR5 and SR6 in dominantly marine early Eocene to late Paleocene Cambay Shale formation, and SR7, SR8/9, and SR11/12 in dominantly freshwater early Paleocene Olpad formation. Only 3 PSs, SR11/12, SR8/9, and SR7 have attained vitrinite reflectance of 0.75% at 45, 7, and 2 mybp, respectively. Chromatographic and isotope data of oils and PS samples suggest that mainly the Olpad source rocks: SR7 and SR8/9 contributed to the discovered oils. The Cambay Shale source rocks, SR5 and SR6, contrary to the prevalent view, possibly have no significant contribution towards the accumulated oils.     

Source rock characteristics and hydrocarbon generation modelling of Upper Cretaceous Mukalla Formation in the Jiza-Qamar Basin,Eastern Yemen

The Upper Cretaceous Mukalla coals and other organic-rich sediments which are widely exposed in the Jiza-Qamar Basin and believed to be a major source rocks, were analysed using organic geochemistry and petrology. The total organic carbon (TOC) contents of the Mukalla source rocks range from 0.72 to 79.90% with an average TOC value of 21.50%. The coals and coaly shale sediments are relatively higher in organic richness, consistent with source rocks generative potential. The samples analysed have vitrinite reflectance in the range of 0.84–1.10 %Ro and pyrolysis T_max in the range of 432–454 °C indicate that the Mukalla source rocks contain mature to late mature organic matter. Good oil-generating potential is anticipated from the coals and coaly shale sediments with high hydrogen indices (250–449 mg HC/g TOC). This is supported by their significant amounts of oil-liptinite macerals are present in these coals and coaly shale sediments and Py-GC (S₂) pyrograms with n-alkane/alkene doublets extending beyond nC₃₀. The shales are dominated by Type III kerogen (HI < 200 mg HC/g TOC), and are thus considered to be gas-prone.One-dimensional basin modelling was performed to analysis the hydrocarbon generation and expulsion history of the Mukalla source rocks in the Jiza-Qamar Basin based on the reconstruction of the burial/thermal maturity histories in order to improve our understanding of the of hydrocarbon generation potential of the Mukalla source rocks. Calibration of the model with measured vitrinite reflectance (Ro) and borehole temperature data indicates that the present-day heat flow in the Jiza-Qamar Basin varies from 45.0 mW/m² to 70.0 mW/m² and the paleo-heat flow increased from 80 Ma to 25 Ma, reached a peak heat-flow values of approximately 70.0 mW/m² at 25 Ma and then decreased exponentially from 25 Ma to present-day. The peak paleo-heat flow is explained by the Gulf of Aden and Red Sea Tertiary rifting during Oligocene-Middle Miocene, which has a considerable influence on the thermal maturity of the Mukalla source rocks. The source rocks of the Mukalla Formation are presently in a stage of oil and condensate generation with maturity from 0.50% to 1.10% Ro. Oil generation (0.5% Ro) in the Mukalla source rocks began from about 61 Ma to 54 Ma and the peak hydrocarbon generation (1.0% Ro) occurred approximately from 25 Ma to 20 Ma. The modelled hydrocarbon expulsion evolution suggested that the timing of hydrocarbon expulsion from the Mukalla source rocks began from 15 Ma to present-day.