Development Phases and Mechanisms of Tectonic Fractures in the Longmaxi Formation Shale of the Dingshan Area in Southeast Sichuan Basin, China     

FAN Cunhui  HE Shun  ZHANG Yu  QIN Qirong  ZHONG Cheng 《《地质学报》英文版》2018,92(6):2351-2366

Shale gas has currently attracted much attention during oil and gas exploration and development. Fractures in shale have an important influence on the enrichment and preservation of shale gas. This work studied the developmental period and formation mechanism of tectonic fractures in the Longmaxi Formation shale in the Dingshan area of ??southeastern Sichuan Basin based on extensive observations of outcrops and cores, rock acoustic emission (Kaiser) experiments, homogenization temperature of fracture fill inclusions, apatite fission track, thermal burial history. The research shows that the fracture types of the Longmaxi Formation include tectonic fractures, diagenetic fractures and horizontal slip fractures. The main types are tectonic high-angle shear and horizontal slip fractures, with small openings, large spacing, low densities, and high degrees of filling. Six dominant directions of the fractures after correction by plane included NWW, nearly SN, NNW, NEE, nearly EW and NW. The analysis of field fracture stage and fracture system of the borehole suggests that the fractures in the Longmaxi Formation could be paired with two sets of plane X-shaped conjugate shear fractures, i.e., profile X-shaped conjugate shear fractures and extension fractures. The combination of qualitative geological analysis and quantitative experimental testing techniques indicates that the tectonic fractures in the Longmaxi Formation have undergone three periods of tectonic movement, namely mid-late Yanshanian movement (82–71.1 Ma), late Yanshanian and middle Himalaya movements (71.1–22.3 Ma), and the late Himalayan movement (22.3–0 Ma). The middle-late period of the Yanshanian movement and end of the Yanshanian movement-middle period of the Himalayan movement were the main fracture-forming periods. The fractures were mostly filled with minerals, such as calcite and siliceous. The homogenization temperature of fracture fill inclusions was high, and the paleo-stress value was large; the tectonic movement from the late to present period was mainly a slight transformation and superposition of existing fractures and tectonic systems. Based on the principle of tectonic analysis and theory of geomechanics, we clarified the mechanism of the fractures in the Longmaxi Formation, and established the genetic model of the Longmaxi Formation. The research on the qualitative and quantitative techniques of the fracture-phase study could be effectively used to analyze the causes of the marine shale gas fractures in the Sichuan Basin. The research findings and results provide important references and technical support for further exploration and development of marine shale gas in South China.  相似文献   

细粒沉积体系类型及特征——以济阳坳陷沙四上—沙三下亚段为例     

王勇  张顺 《地质论评》2021,67(Z1):67z1135-67z1136

正济阳坳陷沙四上亚段泥页岩细粒沉积是下一步油气勘探的主要目标,2020年度页岩油勘探获得重大突破,部署的义页平1和樊页平1页岩油专探井,取得峰值日油105 m~3和200.89 m~3的高产,预示着济阳坳陷页岩油气获得突破,奠定了泥页岩细粒的研究地位。但随着勘探的深入,发现济阳坳陷沙四上亚段泥页岩细粒沉积类型多样、  相似文献   

俯冲-碰撞带硼循环     

郭顺 《矿物岩石地球化学通报》2021,40(5):1049-1060

俯冲带控制着地球内部和表层的物质与能量交换.硼(B)是一个质量轻的流体活动性元素.B及其同位素体系是理解俯冲-碰撞带流/熔体活动和物质循环的重要工具.本文综述了俯冲板块中各储库的硼含量和同位素组成以及主导硼分配的关键矿物.介绍了目前对大洋俯冲带弧前、弧下和弧后深度下硼循环的主要认识;简要介绍了刚起步的大陆俯冲-碰撞带硼循环研究.阐述了含电气石(超)高压变质岩在俯冲带硼迁移研究中的重要性.指出今后需深化含水矿物在不同地温梯度下脱水/熔融过程中硼同位素分馏研究,加强流/熔体包裹体硼同位素分析技术及应用研究.由于B及同位素可有效区分大洋地壳和大陆地壳物质,未来将在造山带演化和地球深部物质循环研究中扮演更重要的角色.  相似文献   

Compression behavior of MICP-treated sand with various gradations     

Xiao  Yang  Zhao  Chang  Sun  Yue  Wang  Shun  Wu  Huanran  Chen  Hui  Liu  Hanlong 《Acta Geotechnica》2021,16(5):1391-1400

Acta Geotechnica - One-dimensional compression tests on quartz sands treated by microbially induced carbonate precipitation (MICP) were carried out to evaluate the effects of gradation and calcium...  相似文献   

Homogeneity and mechanical behaviors of sands improved by a temperature-controlled one-phase MICP method     

Xiao  Yang  Wang  Yang  Wang  Shun  Evans  T. Matthew  Stuedlein  Armin W.  Chu  Jian  Zhao  Chang  Wu  Huanran  Liu  Hanlong 《Acta Geotechnica》2021,16(5):1417-1427

Acta Geotechnica - Microbially induced carbonate precipitation (MICP) has been actively investigated as a promising method to improve soil properties. A burning issue impeding its wide application...  相似文献   

A device for rainfall simulation in geotechnical centrifuges     

Wang  Shun  Idinger  Gregor 《Acta Geotechnica》2021,16(9):2887-2898

Rainfall-induced slope instabilities are ubiquitous in nature, but simulation of this type of hazards with centrifuge modelling still poses difficulties. In this paper, we introduce a rainfall device for initiating slope failure in a medium-sized centrifuge. This rainfall system is simple, robust and affordable. An array of perforated hoses is placed close above the model slope surface to generate the raindrops. The rainfall intensity depends on the centrifuge acceleration and the flow rate of the water supply, which is controlled by the size and number of the tiny pinholes in the hose walls. The rainfall intensities that are tested range from 2.5–30 mm/h, covering the intensity range of moderate, heavy and torrential rainfall events. Our model test with rainfall-induced slope failure shows that this system is capable of generating relatively uniform rainfall of wide intensities and leads to various patterns of slope failure.

  相似文献   

Impact of topography and land-sea distribution on East Asian paleoenvironmental patterns   总被引：1，自引：1，他引：0  

张仲石  王会军  郭正堂  姜大膀 《大气科学进展》2006,23(2):258-266

Much geological research has illustrated the transition of paleoenvironmental patterns during the Cenozoic from a planetary-wind-dominant type to a monsoon-dominant type, indicating the initiation of the East Asian monsoon and inland-type aridity. However, there is a dispute about the causes and mechanisms of the transition, especially about the impact of the Himalayan/Tibetan Plateau uplift and the Paratethys Sea retreat. Thirty numerical sensitivity experiments under different land-sea distributions and Himalayan/Tibetan Plateau topography conditions are performed here to simulate the evolution of climate belts with emphasis on changes in the rain band, and these are compared with the changes in the paleoenvironmental patterns during the Cenozoic recovered by geological records. The consistency between simulations and the geological evidence indicates that both the Tibetan Plateau uplift and the Paratethys Sea retreat play important roles in the formation of the monsoon-dominant environmental pattern. Furthermore, the simulations show the monsoon-dominant environmental pattern comes into being when the Himalayan/Tibetan Plateau reaches 1000–2000 m high and the Paratethys Sea retreats to the Turan Plate.  相似文献   

基于已知特征平面的移动测量系统安置参数检校     

张顺  张帆  李珂 《北京测绘》2020,(3):437-442

安置误差是影响移动测量系统激光点云精度的主要因素之一。当激光点云中存在特征平面时,安置误差会导致该平面与真实平面之间产生较大的偏差,如果存在多个空间上位置关系较好的特征平面,就能够全面反映出系统的安置误差。本文以此为依据,给出了一种基于已知特征平面的移动测量系统安置参数检校方法,并详细阐述了检校场的布设、数据获取及处理等内容。实验证明,该方法是一种简单、可靠的检校方法,具有较高的实用性。  相似文献   

DNQ3型能见度仪故障分析及校准方法研究          下载免费PDF全文

卢舟  王凡  王舜  刘钟中  刘志鹏  佘菁力 《中低纬山地气象》2023,47(2):114-118

为有效提高国家地面气象观测站能见度仪观测数据准确性和设备运行稳定性,对能见度仪开展日常维护、核查校准、数据质控和故障修复等工作显得尤为重要。该文通过对DNQ3型前向散射能见度仪硬件结构和基本工作原理的介绍,以及对一些典型故障进行分析,总结出能见度仪的检测维修流程,归纳了对应的故障解决措施,凝练出该型能见度仪的核查校准和疑误数据质控方法,为一线业务人员开展能见度仪常规维护、故障排查、运行监控等提供借鉴。  相似文献   

海萝抗氧化酶系与失水响应因子表达模式分析     

刘顺  胡自民  张全胜  段德麟 《海洋科学》2019,43(5):1-10

潮间带红藻海萝(Gloiopeltis furcata)对失水胁迫具有很强的耐受能力。为探索海萝周期性失水过程中的响应机制,本研究在24 h内设计了两次连续的失水-复水循环处理,测定了海萝抗氧化酶活力的变化情况。同时,利用转录组测序技术,结合荧光定量PCR方法(qRT-RCR),对海萝失水响应基因的转录表达进行了验证。结果表明:海萝转录组共组装到32681条基因。与对照组相比,处理组共表达了7161条差异表达基因(differentially expressed genes, DEGs)。KEGG分析显示, DEGs分布在代谢、环境信息加工、有机体系统、遗传信息加工、细胞进程等方面。海萝抗氧化酶活力测定发现,抗氧化能力对海萝响应失水胁迫十分重要。过氧化氢酶(CAT)、硫氧还蛋白还原酶(TrxR)、超氧化物歧化酶(SOD)参与抗氧化过程,其中CAT酶活力对海萝抵抗失水胁迫尤为重要。此外,qRT-PCR结果显示,海萝中渗透调节物质红藻糖苷合成的相关基因(GfUGPase、GfGK、GfGPDH)只对初次失水处理有正响应。而热激蛋白70基因(GfHSP70)、碳酸酐酶基因(GfCA)、MYB蛋白编码基因(GfMYB)以及谷胱甘肽S转移酶基因(GfGST)在两次失水过程中其转录水平均有上调表达,它们也参与了海萝失水响应机制。  相似文献