松辽盆地北部石炭—二叠纪地层厚度：来自深反射地震的证据

在松Ⅰ～松Ⅵ6条深反射地震剖面上依据震相特征并结合地质演化过程分析识别石炭—二叠系,分析其层位反射特征及同相轴特征,建立松辽盆地北部地区石炭—二叠系地震震相特征识别标志。主要震相特征为中—强反射能量,局部存在高值,整体同相轴连续—较连续,由南到北、由西向东规律变化。利用已有的钻遇石炭—二叠系的探井资料和地震波传播速度,得到研究区时间-深度转换关系。由研究区石炭—二叠系相位追踪对比后的反射时间分布,计算石炭—二叠纪地层顶界面与底界面在深反射地震时间剖面上的走时之差,通过时深转换得出研究区基底石炭—二叠纪地层厚度和分布。全区地层分布不很均匀,主要在中央隆起带以东地区及西部断陷区出现2个厚度高值区;地层整体由浅到深大致可分为上、中、下3层,且地震震相特征互不相同。松辽盆地北部石炭—二叠系分布对东北地区主力油层之下的深层油气勘探提供了有价值的依据。     

论全球海陆变迁的主要原因

历史发展过程中不少专家学者,对地球上各个大陆形成演化作了多年大量的研究工作,但认识千差万别。如最早的大陆漂移学说,后来又出现海底扩张学说—板块构造学说等等。经过多年研究认为,全球7个大陆不会漂移,而且也无充分依据将地球划分成几个板块。因为板块构造学说的运动机制基本是合理的,但是,板块划分依据不足、各板块的界线不明确、各板块的地质差别及特征不清楚等。所以,笔者认为全球各大陆整体是不分的,各个陆块地质时期的变化,是海陆变迁的结果。     

Late Carboniferous-Early Permian Mafic-Ultramafic Complexes in Beishan,Southwestern Central Asian Orogenic Belt and Their Significance

正Numeral Permian mafic-ultramafic complexes occur in the Beishan terrane atthe northeastern margin of the Tarim craton,southwestern Central Asian Orogenic Belt,including the Pobei,Cantoushan,Bijiashan,Hongshishan,Xuanwoling,Zhongposhan and Luodong etc.,intrusions (Qin et al.,2011;Zhang et al.,2017;Xue et al.,2018).These Beishan mafic-ultramafic complexes are composed of peridotite,pyroxenite,troctolite and gabbro with significant cumulate rhythmic layers of magmatic     

Initiation Timing of the Jiamusi–Yitong Fault Zone in NE China

The NE–striking Jiamusi–Yitong fault zone(JYFZ) is the most important branch in the northern segment of the Tancheng–Lujiang fault zone. The precise shearing time of its large–scale sinistral strike–slip has yet to determined and must be constrained. Detailed field investigations and comprehensive analyses show that strike–slip faults or ductile shear belts exist as origination structures along the western region of Yitong Graben. The strike of the shear belts trend to the NE–SW with steep mylonitic foliation. The zircon U–Pb dating result for the granite was 264.1±1 Ma in the ductile shear belt of the JYFZ. The microstructural observation(rotated feldspar porphyroclasts, S–C fabrics, and quartz c–axis fabrics, etc.) demonstrated the sinistral shearing of the ductile shear zones. Moreover, the recrystallized quartz types show a transitional stage of the subgrain rotation toward the recrystallization of the grain boundary migration(SR–GBM). Therefore, we suggest that the metamorphic grade of the shear zone in the ductile shear zones should have reached high greenschist facies conditions, and the deformation temperatures should approximately 450–500°C, which is obviously higher than the blocking temperature of muscovite(300–400°C). Hence, the ~(40)Ar/~(39)Ar isochron age of muscovite from ductile shear zones should be a cooling age(162.7±1 Ma). We infer that the sinistral strike–slipping event at the JYFZ occurred in the late Jurassic period, and it was further inferred from the ages of the main geological events in this region that the second sinistral strike–slip age of the Tancheng–Lujiang fault zone occurred during the period of tectonic movements in the Circum–Pacific tectonic domain. This discovery also indicates the age of the Tancheng–Lujiang fault zone that stretches to northeastern China. The initiation of the JYFZ in the late Jurassic is related to the speed and direction of oblique subduction of the west Pacific Plate under the Eurasian continent and is responsible for collision during the Jurassic period.     

Petrological and Organic Geochemical Characteristics of Oil Sands from the Middle Jurassic Yan'an Formation in the Southern Ordos Basin,China

An integrated petrological and geochemical analysis of surface and drilled oil sands was conducted to assess the organic matter origin/type, thermal maturity and paleoenvironment. Petrographic analysis of the oil sand used to establish the relationships between porosity and permeability with bulk density, RQI, NPI and FZI. The strong correlation between reservoir quality index (RQI) and permeability (R² = 0.98) reveal that porosity has a good correlation to RQI. The biomarker signatures of the analyzed oil reveal predominance of subaquatic‐derived source input with mainly land plant materials. This was indicated based on the average concentration of αααC27:C28:C29 sterane 20R of about 38%, 22% and 40% respectively. This interpretation is also supported by high values of tricyclic terpane/αβC30 hopane and regular sterane/αβC30 hopane. An anoxic condition of deposition within a lacustrine paleoenvironment that attributed to the enhancement of the preservation of the organic matters in the area were indicated based on the low Pr/Ph ratios (average 0.74), low values of αβC31‐22R‐hopane/αβC30 hopane ratios and high C26/C25 tricyclic terpane ratios as well as the presence of gammacerane and a low water salinity. Biomarker maturity parameters show that the extracted oil sand has entered the early oil window stage.     

山东文登ZKCW01干热岩钻孔地质特征及资源潜力

山东半岛属于中国干热岩潜力靶区之一。基于研究区地质、地球物理和地热地质等资料,经大地电磁和可控源勘探,确定了干热岩钻孔位置。通过钻探、测井、取芯及岩矿分析测试,全面得到深部文登花岗岩体规模、裂隙储层空间分布、深部地温及地温梯度、花岗岩热物性参数和岩石力学参数等,建立干热岩三维地质模型,通过数值模拟分析了其发电能力。研究区侵入岩、构造断裂发育,大地热流值为48～85mW/m2,地热异常区地温梯度为5. 3~18. 59℃/100m,表明研究区具有非常好的深部地热能赋存条件。数值模拟揭示,对研究区4000m储层进行人工激励后,以30kg/s的注入速率,17℃的注入水,运行20年后,产出水温度从168℃降低到149℃,降低了11. 3%;流动阻抗在上升至0. 076MPa/(kg/s);年发电量3. 7~3. 4MW,高于法国Soultz的发电量。     

洪水致弯曲河道挡墙稳定性衰变

天然河道蜿蜒曲折,河湾处环流助长紊动、引发凹岸淘蚀冲刷,导致沿河公路挡墙水毁频发。针对弯道水流运动规律,对洪水条件下弯道挡墙进行受力分析;基于挡墙稳定性分析力学模型,推导了弯曲河道挡墙稳定系数计算公式,给出挡墙基底极限冲深计算方程。通过算例验证了在河湾平缓条件下弯道洪水冲击计算的合理性,并对挡墙稳定性衰减影响因素进行分析。结果表明：洪水上涨时,在墙底未发生冲刷条件下,随着弯道处洪水对挡墙的冲击荷载增大,挡墙稳定性提高;在墙底发生冲刷条件下,挡墙稳定性降低,墙底淘蚀可能导致挡墙倾覆失稳。洪水陡落时,挡墙稳定性随挡墙前后水位差增大而降低,挡墙的抗滑稳定系数衰减速度比抗倾覆稳定系数衰减速度更快,挡墙滑移失稳可能性较大。得出的挡墙稳定系数计算方法的结果与现场情况基本吻合,可为类似沿河挡墙的设计与研究提供理论参考。     

多信息关联的辫状河储层夹层预测方法研究:以南苏丹P油田Fal块为例

辫状河储层的夹层预测是油藏描述的重点内容。目前夹层的预测主要集中于夹层发育模式研究和心滩坝体的构型单元解剖,且多运用单一的预测方法。南苏丹P油田辫状河储层夹层类型多、规模差异大、分布复杂,定量表征难度较大,在文献调研的基础上,从夹层的沉积成因入手,依据不同沉积方式形成的沉积砂体及其内部泥质夹层形态与结构不同的特点,综合岩心、测井与地震等多种资料,提出多信息关联的辫状河储层夹层预测方法。在密井网区建立骨架剖面与三角网小剖面,运用测井资料的垂向高分辨率与地震资料的横向强连续性特征确定不同类型夹层的井间发育规模;在建立岩相模型的基础上,以隔层厚度分布图为约束条件,采用确定性建模方法建立稳定泥岩隔层分布模型;以沉积微相研究结果和夹层规模预测结果为约束条件,采用随机建模方法分别在砂岩相和泥岩非隔层相中模拟心滩坝、河道和各类型夹层的分布;最终确定了研究区主要存在4种成因类型的夹层,并在多信息关联的基础上建立反映多类型夹层空间分布的辫状河储层精细地质模型。研究发现,对于厚度大于2 m的夹层可以通过井震结合的方法验证其井间规模,定量确定不同层位、不同类型夹层顺物源与切物源的发育规模,为夹层模型的建立奠定基础;基于克里金插值方法建立的岩相概率模型增加岩相模型准确率至94%;以隔层厚度平面分布图为约束条件的确定性建模方法可准确建立砂组及小层间隔层分布模型;在各成因类型夹层井间规模预测的基础上,基于目标的随机模拟方法可以针对不同成因类型夹层的发育形态、数量、规模和趋势分别设定模拟参数,确定性与随机性相结合,实现了辫状河储层精细地质模型的建立。同时,对相关储层的夹层预测具有一定的指导作用。     

基于时频分析与深度学习的结构震后损伤评估

为评估地震后钢筋混凝土(RC)框架结构的损伤状态,提高损伤评估的效率和精度,文章提出一种基于时频分析和一维卷积神经网络(1D-CNN)的地震损伤评估方法。首先利用增量动力时程分析对一个6层RC框架结构进行地震损伤模拟,并根据最大层间位移角对加速度信号进行损伤程度的标定,以此来获取数据样本,随后应用五种不同的时频分析方法对原始信号进行处理;然后建立基于1D-CNN的地震损伤评估模型,并利用贝叶斯优化算法寻找模型中的最优参数组合;最后评估所提出模型方法在噪声情况下的泛化能力。研究结果表明：五种时频分析方法中,小波散射变换方法的准确率最高,达92.5%,且计算速度也最快,仅需144 s;另外在噪声下该方法仍可以保持较高的损伤评估准确率,具有较好的鲁棒性和泛化能力。