基于广域电磁法的页岩气有利区预测——以渝东北巫山地区为例     

孟凡洋  包书景  陈科  王鹏  李柳德 《物探与化探》2018,(1):68-74

渝东北巫山地区是重要的页岩气勘探远景区,勘探程度较低。本次研究以岩石物理和测井数据为基础,以广域电磁法为手段,开展该区的页岩气有利区评价。通过对地表样品及井孔电阻率测井资料的分析,揭示研究区目的层富有机质页岩层电阻率表现为明显低阻特征,与上覆下伏地层电性差异明显,表明本区分布的上奥陶统五峰—下志留统龙马溪组富有机质页岩具备开展电法勘探工作的物性条件。在对电磁资料处理解释的基础上,查明了重庆巫山地区"隆凹相间"的构造格局,断裂性质主要为逆断层;目的层上奥陶统五峰组—下志留统龙马溪组富有机质泥页岩连续稳定分布,低阻特征明显,埋深范围在800~4 800 m之间。综合考虑目的层页岩电阻率、极化率、埋深等因素,预测出页岩气有利区3个,区内富有机质页岩发育,页岩气勘探前景较好。  相似文献   

广域电磁法在豫西地区济源凹陷古生界油气勘探中的应用     

王丹丹 《地质与勘探》2023,59(2):328-336

豫西地区济源凹陷由山地和丘陵组成,地形条件复杂,地震资料品质较差,盆地内断裂形态结构、深部古生界展布特征等不清楚,制约着济源凹陷的油气勘探和资源潜力评价。本文利用广域电磁法在豫西地区济源凹陷进行方法应用研究,采用“地球物理资料综合处理解释一体化系统”进行数据处理与反演,获得了地下真实的电性特征,建立了目标层与视电阻率的电性关系,刻画了研究区目标层的构造特征。本研究查明了济源凹陷西部斜坡的断裂结构特征,新识别出12条断裂;揭示石炭-二叠系厚度分布范围在200～1800 m,最大埋深2200 m;奥陶系顶界面埋深分布在300～2450 m,呈“条带状”展布,得到了地质调查井岩心编录的证实。  相似文献   

钻孔瞬变电磁方法探测越界开采采空区的应用     

范涛  李萍  赵兆  李巍  赵睿  张鹏  姚伟华  李宇腾  房哲 《煤田地质与勘探》2022,50(1):20-24

煤矿井下越界开采扰乱煤炭资源开发秩序,同时存在巨大的安全隐患,准确探测越界开采采空区及其边界对安全采掘极为重要。常规的矿井瞬变电磁探测方法容易受到巷道中的金属和电磁信号干扰,探测精度有限,难以满足采空区边界精准解释的需求。为了解决这一问题,提出一种钻孔中收发信号的钻孔瞬变电磁方法和施工工艺,利用其远离巷道和靠近异常体的特点,提高异常信号在实测数据中的占比;并研究可行域约束的OCCAM反演算法,进一步减小体积效应影响,实现了对越界开采采空区的电阻率精细成像。结合山西某煤矿的工程实践,对该方法精准探测邻矿越界开采采空区规模、性质的实用性和有效性进行了检验。结果表明,钻孔瞬变电磁方法是矿井地球物理技术与钻探工艺技术的高效结合和有益补充,基于可行域约束的OCCAM反演算法能够有效应用于越界开采采空区的边界精确成像解释。   相似文献   

Genetic model and exploration target area of geothermal resources in Hongtang Area,Xiamen, China          下载免费PDF全文

Liu Chun-lei  Lu Chen-ming  Li Ya-song  Hao Qi-chen  Cao Sheng-wei 《地下水科学与工程》2022,10(2):128-137

The geothermal resources in Fujian Province are mainly hydrothermal resources of medium-low temperature. To better understand the whole process and conditions of heat control in the middle and deep crust, this study focuses on the analysis of heat accumulation model in Hongtang Area of Xiamen, and the main conditions of the model such as faults and sags are explored and interpreted in detail by using gravity and wide-field electromagnetic methods. 4 main faults (F33, F2, F12 and HT-F1) and 10 secondary faults (HT-F2, HT-F3, HT-F4, HT-F5, HT-F6, HT-F7, HT-F8, HT-F9, HT-F10 and HT-F11) were inferred, and the distribution range of sags was delineated. The convective geothermal system is composed of four components: Heat source, geothermal reservoir, heat-conductive fault and heat retaining cover, which form a quaternary heat accumulation model. According to the model, the intersection of the main faults F12, HT-F1 and F33 can be delineated as the primary target area of geothermal exploration, while the intersection of the secondary faults (F12 and HT-F6; F12 and HT-F2; HT-F9, HT-F10 and F12; F12 and HT-F11; F33 and HT-F3; HT-F8 and HT-F3; HT-F2, HT-F10 and HT-F1) can be delineated as the secondary target area. Borehole DR01, which is located in the primary target area, shows that the water temperature increases from fast to slow in the depth range of 0–500 m, and stays at 36℃ below 500 m. The reliability of the heat accumulation model and the target area was tested via geothermal boreholes, which is of great significance to the exploitation and utilization of geothermal resources in Hongtang Area of Xiamen.  相似文献   

Development dynamics of intense solar proton flares     

A. B. Struminsky  I. V. Zimovets 《Astronomy Letters》2007,33(9):615-621

We consider the relationship of electromagnetic radiation in the three most intense flares of solar cycle 23, more specifically, those of October 28, 2003, January 20, 2005, and September 7, 2005, to the acceleration and release of protons into interplanetary space. The impulsive phase of these flares lasted ～ 20 min and consisted of at least three energy release episodes, which differed by their manifestation in the soft (1–8 Å, GOES) and hard (>150 keV, INTEGRAL) X-ray ranges as well as at radio frequencies of 245 MHz and 8.8 GHz. The protons and electrons were accelerated in each episode, but with a different efficiency; the relativistic protons were accelerated only after 5–6min of impulsive-phase development after the onset of a coronal mass ejection. It is at this time that maximum hard X-ray fluxes were observed in the September 7, 2005 event, which exceeded severalfold those for the other two flares considered. We associate the record fluxes of protons with energies > 200MeV observed in the heliosphere in the September 7, 2005 event with the dynamics of the impulsive phase. The extreme intensities of the microwave emission in the October 28, 2003 and January 20, 2005 events were probably attributable to the high-energy electron trapping conditions and did not reflect the acceleration process.  相似文献   

航空激光测深仪海面和海底激光入射点分布     

叶修松  王耿峰  黄谟涛  赵东明 《测绘学院学报》2010,(2)

依据卵形扫描系统的原理,以严格的数学推导为基础,推导了海平面激光入射点坐标的计算公式及相应的优化算法。建立起了海底激光入射点坐标及该点垂直水深的严密计算模型。通过仿真试验,得出了激光镜面反射点X轴的修正量随驱动电机转角的变化趋势,单个周期的海面激光入射点分布及30个周期的激光脉冲海面重叠图和试验脉冲对应的定位角度数据。同时给出了每个测量数据对应扫描镜中心点的位置和每个激光发射时对应XYZ坐标系中坐标原点的经纬度的计算方法。  相似文献   

Sponge and coral zooxanthellae in heat and light: preliminary results of photochemical efficiency monitored with pulse amplitude modulated fluorometry     

Christine H. L. Schönberg  Ryota Suwa  Michio Hidaka  & William Kok Weng Loh 《Marine Ecology》2008,29(2):247-258

  相似文献   

Advancing process‐based watershed hydrological research using near‐surface geophysics: a vision for,and review of,electrical and magnetic geophysical methods     

D. A. Robinson  A. Binley  N. Crook  F. D. Day‐Lewis  T. P. A. Ferré  V. J. S. Grauch  R. Knight  M. Knoll  V. Lakshmi  R. Miller  J. Nyquist  L. Pellerin  K. Singha  L. Slater 《水文研究》2008,22(18):3604-3635

We want to develop a dialogue between geophysicists and hydrologists interested in synergistically advancing process based watershed research. We identify recent advances in geophysical instrumentation, and provide a vision for the use of electrical and magnetic geophysical instrumentation in watershed scale hydrology. The focus of the paper is to identify instrumentation that could significantly advance this vision for geophysics and hydrology during the next 3–5 years. We acknowledge that this is one of a number of possible ways forward and seek only to offer a relatively narrow and achievable vision. The vision focuses on the measurement of geological structure and identification of flow paths using electrical and magnetic methods. The paper identifies instruments, provides examples of their use, and describes how synergy between measurement and modelling could be achieved. Of specific interest are the airborne systems that can cover large areas and are appropriate for watershed studies. Although airborne geophysics has been around for some time, only in the last few years have systems designed exclusively for hydrological applications begun to emerge. These systems, such as airborne electromagnetic (EM) and transient electromagnetic (TEM), could revolutionize hydrogeological interpretations. Our vision centers on developing nested and cross scale electrical and magnetic measurements that can be used to construct a three‐dimensional (3D) electrical or magnetic model of the subsurface in watersheds. The methodological framework assumes a ‘top down’ approach using airborne methods to identify the large scale, dominant architecture of the subsurface. We recognize that the integration of geophysical measurement methods, and data, into watershed process characterization and modelling can only be achieved through dialogue. Especially, through the development of partnerships between geophysicists and hydrologists, partnerships that explore how the application of geophysics can answer critical hydrological science questions, and conversely provide an understanding of the limitations of geophysical measurements and interpretation. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

地下电短天线的输入特性分析     

孙建国  康国军  张辉 《吉林大学学报(地球科学版)》2004,34(1):128-133

地下电短天线的输入导纳是其几何尺寸、工作频率及地下和近地表物质(围岩及土层)电磁参数的函数.通过分析其变化规律得到下列结论:(1)短天线的输入导纳随频率的变化比较复杂.当频率较低时,短天线的输入电导随地下物质电磁参数的变化不明显,而输入电纳基本上随着频率的增高呈线性变化.(2)在频率比较低时,介电常数的变化对短天线的输入电导影响不明显,存在有一个电导曲线重合频段.对于低阻物质,这个重合频段的上限比较低;对于高阻物质,重合频段的上限升高.对于输入电纳,当电阻率和频率两者都较高时,其对介电常数的变化比较敏感.(3)输入导纳对低阻物质反应敏感,而对具有中等以上电阻率的物质基本上退化成为一条相同的频率变化曲线.(4)短天线的输入导纳值随其几何尺度的增加而增加.  相似文献   

二维圆柱坐标下FDTD法对多频电磁波测井的数值模拟   总被引：5，自引：2，他引：3  

刘四新 《吉林大学学报(地球科学版)》2004,34(2):283-286

在介质围绕Z轴旋转对称的情况下,三维直角坐标下的麦克斯韦方程可变成两组分别对应TM波和TE波的二维柱坐标下的偏微分方程.采用线圈作为电磁波测井的发射器和接收器的时候,可采用TE波对应的方程,这时相当于磁极子的情况.而采用电偶极子作为发射和接收器的时候,则对应TM波的方程.采用时间和空间均为二阶精确的有限差分方法,将偏微分方程进行差分化.这样,空间的电磁场可由时间域有限差分法(FDTD)来求解.  相似文献