静水条件下背斜圈闭系统石油运移和聚集模拟实验及机理分析   总被引：1，自引：0，他引：1       下载免费PDF全文

曾溅辉  王洪玉 《地质论评》2001,47(6):590-595

静水条件下背斜圈闭系统石油运移和聚集的模拟实验表明：（1）不同砂层组合方式的背斜圈闭系统中，油的运移方向、路径和通道不同，其中，均质和反韵律砂层组成的背斜圈闭系统油的运移方向、路径和通道比较简单，而正韵律组成的背斜圈闭系统中油的运移方向、路径和通道比较复杂；（2）油的充注速率对油的运移方向、路径和通道具有重要的影响，当充注速率较小时，油仅在一些渗透率较高的砂层中运移，当充注速率较大并超过渗透率较高的砂层的运载能力时，则油可以进入一些渗透率较低的砂层；（3）运载层的岩性组合和渗透率级差以及油充注速率和充注方向等对油气运移的散失量和运移效率产生重要的影响，一般来说，反韵律砂层组成的背斜圈闭系统中油的运聚效率较高，均质砂层组成的背斜圈闭系统次之，而正韵律砂层组成的背斜圈闭系统中油的运聚效率比较低；（4）油的运移形式表现为跳跃和脉动的特点。  相似文献   

FOCAL MECHANISM SOLUTIONS AND STRESS FIELD OF THE 2019 CHANGNING,SICHUAN MAINSHOCK AND ITS MODERATE-STRONG AFTERSHOCKS(M_S≥4.0)          下载免费PDF全文

LIANG Shan-shan  XU Zhi-guo  SHENG Shu-zhong  ZHANG Guang-wei  ZHAO-Bo  ZOU Li-ye 《地震地质》1979,42(3):547-561

A M_S6.0 earthquake with shallow focal depth of 16km struck Changning County, Yibin City, Sichuan Province at 22:55: 43(Beijing Time)on 17 June 2019. Although the magnitude of the earthquake is moderate, it caused heavy casualties and property losses to Changning County and its surrounding areas. In the following week, a series of aftershocks with M_S≥4.0 occurred in the epicentral area successively. In order to better understand and analyze the seismotectonic structure and generation mechanism of these earthquakes, in this paper, absolute earthquake location by HYPOINVERSE 2000 method is conducted to relocate the main shock of M_S6.0 in Changning using the seismic phase observation data provided by Sichuan Earthquake Administration, and focal mechanism solutions for Changning M_S6.0 main shock and M_S≥4.0 aftershocks are inferred using the gCAP method with the local and regional broadband station waveforms recorded by the regional seismic networks of Sichuan Province, Yunnan Province, Chongqing Municipality, and Guizhou Province. The absolute relocation results show that the epicenter of the main shock is located at 28.35°N, 104.88°E, and it occurred at an unusual shallow depth about only 6.98km, which could be one of the most significant reasons for the heavier damage in the Changning and adjoining areas. The focal plane solution of the Changning M_S6.0 earthquake indicates that the main shock occurred at a thrust fault with a left-lateral strike-slip component. The full moment tensor solution provided by gCAP shows that it contains a certain percentage of non-double couple components. After the occurrence of the main shock, a series of medium and strong aftershocks with M_S≥4.0 occurred continuously along the northwestern direction, the fault plane solutions for those aftershocks show mostly strike-slip and thrust fault-type. It is found that the mode of focal mechanism has an obvious characteristic of segmentation in space, which reflects the complexity of the dislocation process of the seismogenic fault. It also shows that the Changning earthquake sequences occurred in the shallow part of the upper crust. Combining with the results from the seismic sounding profile in Changning anticline, which is the main structure in the focal area, this study finds that the existence of several steep secondary faults in the core of Changning anticline is an important reason for the diversity of focal mechanism of aftershock sequences. The characteristics of regional stress field is estimated using the STRESSINVERSE method by the information of focal mechanism solutions from our study, and the results show that the Changning area is subject to a NEE oriented maximum principal stress field with a very shallow dipping and near-vertical minimum principal stress, which is not associated with the results derived from other stress indicators. Compared with the direction of the maximum principal compressive stress axis in the whole region, the direction of the stress field in the focal area rotates from the NWW direction to the NEE direction. The Changning M_S6.0 earthquake locates in the area with complex geological structure, where there are a large number of small staggered fault zones with unstable geological structure. Combining with the direction of aftershocks distribution in Changning area, we infer that the Changning M_S6.0 earthquake is generated by rupturing of the pre-existing fault in the Changning anticline under the action of the overall large stress field, and the seismogenic fault is a high dip-angle thrust fault with left-lateral strike-slip component, trending NW.  相似文献   

Finite element modelling for evaluation of apparent resistivity over complex structures     

V. K. Gaur  G. C. Nayak  P. K. Gupta 《Journal of Earth System Science》1980,89(1):43-49

The paper presents a computational algorithm designed for efficient modelling of apparent resistivity over complex geological structures, using finite element method. The algorithm can be used to study variations of apparent resistivities using any electrode configuration at any point on the earth’s surface, not necessarily regular. A Schlumberger apparent resistivity sounding curve over a buried anticline, is presented here as an example and compared with the corresponding analytical curve, to demonstrate the correctness of the FEM algorithm. The various potential derivatives required for the computation of apparent resistivities evaluated through different electrode configurations have been obtained by calculating the ‘influence coefficients’ using reciprocal theorems, an approach successfully applied in structural engineering. In essence, a set of self balancing nodal currents, obtained from the appropriate derivative(s) of the shape functions of the elements contributing to the point of observation, is applied as the load vector. The resulting quantities corresponding to the potential distribution in traditional finite element method, then, turn out to be the potential derivatives at the point of observation for different positions of the current electrodes. These are known as influence coefficients. The continuum nature of the domain beyond the region of interest has been modelled by using ‘infinite elements’ across which the potential is assumed to decay exponentially.  相似文献   

湖山背斜构造变形差异的形成和演化     

杨为民  钱守荣  周治安 《安徽地质》1996,(3)

通过对湖山背斜构造变形的野外观察，认为背斜两翼地层在厚度、变形特征及个别层位岩性上的差异，非沉积作用形成，而是由于各层之间的韧性差异以及不同岩性组合在褶皱后期的压肩作用下形成的。这种小范围内不同构造部位同一地层的变形差异，应按构造地层学的研究方法、手段去认识。  相似文献   

柴达木盆地北缘南八仙背斜深、浅断裂系统耦合分析     

王彦博  张永庶  肖安成  汪立群  沈亚  吴磊 《高校地质学报》1997,25(5):741

柴达木盆地内部发育有丰富的基底和浅层断裂，二者之间的成因机制目前还存在较大争议。文章基于高精度三维地 震反射数据和钻井资料，对柴达木盆地北缘南八仙背斜的深、浅断裂系统的几何形态和相互耦合关系进行了分析。南八仙 地区主要发育两条近EW走向的高角度基底断裂，分别为南倾的马仙断裂和北倾的仙南断裂，都是中生代晚期就开始发育 的老断裂，并在新生代重新活化。在新生界内部还发育NW走向和近EW走向两组浅层正断层体系，断距都很小。NW走向 正断层主要位于马仙断裂南侧（上盘），呈雁列式排列。近EW走向正断层范围较小，仅局限在南八仙背斜核部、仙南断裂 上部，由一系列近平行的正断层组成，在仙南断裂上部形成一个小型的地堑构造，切割了NW走向的正断层体系。分析认 为NW走向正断层与马仙断裂左旋走滑导致的尾端拉张有关，而近EW走向正断层体系与高角度仙南断裂逆冲活动导致的 浅层剪切拉张有关。综合前人研究成果认为柴达木盆地广泛存在的浅层断裂成因多变，深、浅断裂耦合关系十分复杂，先 存断裂在新生代构造活动中起到了一定的控制作用。  相似文献   

黄陵背斜周缘早古生代有机壳化石的光学特性与有机质成熟度     

陈善庆 《地球学报》1995,16(2):211-226

本文主要研究扬子地台西部黄陵背斜周缘早古生代有机壳化石的特征、光学特性和有机质成熟度规律，同时较为详细地研究了有机壳化石反射率随热成熟度变化特点与镜质组反射率之间的关系。提出该区以有机壳化石反射率为主要指标的有机质成熟度划分方案。认为笔石、几丁虫和虫牙等有机壳化石在形态、结构和构造上具有各自的特征，并具有突起、反射色、显微结构构造、非均性、异向光性、反射率和双反射现象等光学特征。有机壳化石反射率与  相似文献   

断块运动与中生代济源盆地的演化   总被引：1，自引：0，他引：1       下载免费PDF全文

陈传诗  苏现波 《沉积与特提斯地质》1995,(1):18-23

晚三叠世，济源盆地南部与北部的岩相古地理面貌及充填特征存在着明显的差异；早中侏罗世盆地南部隆起，北部继承性机降，直到中侏罗世未盆地完全封闭。这种差异是由盆地内部黄河断裂的同沉积活动造成的。  相似文献   

Structural analysis of the Tabaco anticline,Cerrejón open-cast coal mine,Colombia, South America     

《Journal of Structural Geology》2016

The Tabaco anticline is a 15 km long, south plunging, east-vergent anticline in northern Colombia, close to the transpressional collisional margin between the Caribbean and South American plates. In the Cerrejón open-cast coal mine, systematic mapping of coal seams in the middle to upper Paleocene Cerrejón Formation has yielded an exceptional dataset consisting of 10 horizontal slices (sea level to 90 m elevation, regularly spaced at 10 m intervals) through the anticline. Coal seams and fault traces in these slices are used to construct a 3D model of the anticline. This 3D model shows tighter folds within lower coal seams, NW-vergent thrusts and related folds on the gentler western limb, and strike-slip faults on the steeper eastern limb. Fault slip-tendency analysis is used to infer that these two faulting styles resulted from two different stress fields: an earlier one consistent with thrusting and uplift of the Perijá range, and a later one consistent with strike-slip faulting (Oca, Ranchería and Samán faults). Our preferred interpretation is that the anticline developed its eastern vergence during the early stages (late Paleocene-early Eocene) of tilting of the Santa Marta massif. Later NW-vergent thrusting on the western limb (early to middle Eocene) was related to western propagation of the Perijá thrust system. These results contribute to the understanding of the structural evolution of the area. They are also a good example of the complex interplay between detachment folding, thrusting, and strike-slip faulting during the growth of a km-size fold in a transpressive setting.  相似文献   

贝尔凹陷苏德尔特构造带的形成与演化   总被引：1，自引：0，他引：1       下载免费PDF全文

谢昭涵  鲜地  罗静爽  杨宝泉  乐靖  王少波 《中国地质》2016,(4):1266-1279

苏德尔特构造带是海拉尔盆地贝尔凹陷的重要油气聚集带之一。使用平衡剖面技术和基于斜向剪切模型的人字形桁架法对苏德尔特构造带及其两侧的贝西断陷和贝中断陷进行了详细的构造几何学和运动学解析,认为在南屯期近SN向伸展,形成近EW向断陷盆地群之后,又叠加了大磨拐河组早期的短时间NW向伸展,以及此后的坳陷沉降,才形成了苏德尔特构造带特殊的构造样式。贝中断陷的东侧边界断层是整个贝尔凹陷在大磨拐河组早期伸展的主干边界断层,并且断层面具有坡坪式特征。苏德尔特构造带是发育于第一阶断坪上部的"滚动背斜",是重力和边界断层几何形态共同控制的结果,形成机制属于重力影响下的横弯褶皱作用,而非侧向挤压引起的纵弯褶皱作用。  相似文献   

卢氏县泥沟金矿点成矿性研究及其找矿意义     

阎五成 《河南国土资源》1998,(1)

作者对泥沟金矿点的韧—脆性剪切带,不同围岩物理、化学性质差异,金矿物质来源,导矿构造、储矿构造等地质特征的成矿性进行了详细分析、对比和研究。以矿体（点）为线索,指出了进一步找矿方向  相似文献