紫金山地区煤系致密砂岩储层特征及主控因素     

孙泽飞  史建儒  连碧鹏  康志帅  申建  杨函 《吉林大学学报(地球科学版)》2019,49(4):959-969

鄂尔多斯盆地东北缘紫金山地区上古生界煤系致密砂岩气资源潜力大,是我国当前非常规天然气勘探的重要地区之一。通过铸体薄片、扫描电镜、孔渗测试和压汞实验等分析测试,结合钻井和测井资料,分析了致密储层的岩石学、孔隙、物性和含气性特征。结果表明：紫金山地区煤系砂岩储层以岩屑砂岩为主,石英和岩屑体积分数高,长石体积分数低,成分成熟度和结构成熟度中等;孔隙类型以溶蚀孔为主,孔隙结构以中孔细喉和小孔细喉为主;孔隙度主要分布在2.00%~12.00%之间,平均6.96%;渗透率主要为0.01×10^-3~1.00×10^-3 μm²,平均为0.36×10^-3 μm²,孔渗相关性较好,与后期溶蚀作用有关;含气储层平均厚度为10.3 m,占砂岩储层总厚度的29%,含气饱和度为40.4%。储层发育主要受沉积作用、压实作用和溶蚀作用控制,沉积作用控制了储层形成的物质基础和空间展布,不同环境下沉积的岩石成分直接影响了压实作用的强弱,砂岩、泥岩、煤层叠置发育的特征为溶蚀作用奠定了基础;压实作用是造成储层致密的最主要因素;溶蚀作用是区内储层物性改善的决定性因素;紫金山岩浆热作用和喷发作用进一步加强了溶蚀作用。  相似文献   

山西省灵丘小青沟-流砂沟银锰多金属矿床特征及矿床成因研究   总被引：5，自引：0，他引：5       下载免费PDF全文

高昊 《地质找矿论丛》2004,19(2):87-91

小青沟-流砂沟银锰矿床为中低温热液矿床,其锰矿经氧化淋滤富集成氧化锰矿床.燕山期火山作用为其提供了热源.五台群变质岩和长城系高于庄组作为银锰多金属矿源层.  相似文献   

山西省左云县煤层复采引起地表变形机制浅析          下载免费PDF全文

韩文德  刘探宝  郭美萍 《地质找矿论丛》2004,19(1):55-58

采空塌陷的发育程度由内因、外因共同决定.自然地理地质环境背景条件为内因,人类工程活动为外因.内因决定了采空塌陷的分布区域,外因则控制它的发育程度.内因通过外因表现出来.  相似文献   

鄂尔多斯盆地东北部山西组下段基准面旋回与聚煤作用     

梁积伟  李文厚  张峰  林峰  郭艳琴  陈全红  王若谷 《煤田地质与勘探》2007,35(1):7-11

依据基准面旋回的原理,应用露头、钻井和测井资料,通过沉积相分析、基准面对比和密集数据控制的平面制图,研究了鄂尔多斯盆地东北部山西组下段煤层在基准面旋回中的位置、煤层在纵向和横向的变化和平面分布。结果表明:煤层的形成与基准面旋回和相分异作用有关,煤层形成于短期基准面上升的晚期。煤层的分布与河道呈互补关系。在远离河道的泥炭沼泽区,煤层厚度大,灰分低,所夹矸石层少。向河道方向,煤层分叉变薄,灰分高,向碎屑岩过渡。从山23到山21,厚煤层的分布总体上呈向北退却的趋势,反映了山西组下段构成一个中期基准面上升的过程。   相似文献   

晋东北地区燕山运动的基本特征——来自1:25万应县幅区域地质调查的总结   总被引：2，自引：0，他引：2  

赵祯祥  杜晋锋 《地质力学学报》2007,13(2):150-162

晋东北地区燕山期地壳活动剧烈而频繁, 经历了3次由伸展→挤压转换→隆升和岩浆活动过程。燕山运动早期形成早侏罗世断陷盆地和中侏罗世挤压坳陷型聚煤构造盆地; 中期中晚侏罗世形成被NW、NE向深大断裂围限的火山断陷盆地, 中基性-酸性火山喷发和浅成、超浅成中酸性岩浆侵入, 晚侏罗世末形成了一系列NNE向褶皱和逆冲推覆构造带; 晚期早白垩世再次形成断陷盆地和开阔平缓褶皱, 义县组不整合在火山岩之上, 晚白垩世处于挤压造山后的山体隆升阶段, 左云组不整合在义县组之上, 伴随有壳源型花岗岩侵入, NW、NE向断裂复活, 形成地堑、地垒式断裂组合, 导致山体隆升。   相似文献   

鄂尔多斯盆地长北气田山西组2 段高分辨率层序构型与砂体预测   总被引：1，自引：0，他引：1  

郑荣才  周祺  王华  李凤杰 《高校地质学报》2009,15(1):69

以钻井测井、岩芯描述和样品分析为基础,高分辨率层序分析为技术方法对鄂尔多斯盆地长北气田山西组2段进行了精细的沉积相和层序分析,将山2段确定为海相辫状河三角洲沉积体系,并将其划分为1个长期、2个中期、4个短期和9个超短期基准面旋回层序和2大类5种基准面旋回结构类型。分析了不同级别基准面旋回层序的叠加式样与砂体展布和演化规律,建立了以中期基准面升、降半旋回相域为等时地层单元的山2段地层格架和对单砂层进行了等时追踪对比,确定中期上升期是三角洲河道砂体连续叠置形成巨厚砂体的最有利时期,洪泛期为细粒沉积物沉积期,也是隔层和局域性盖层主要发育期,下降期受侵蚀影响河道砂体不发育。以高分辨率层序分析为基础,建立等时地层格架为约束条件,结合单砂体为等时地层单元编制砂岩等厚图、砂/泥比等值线图和沉积微相图,对长北气田山2段砂体分布开展序贯指示三维模拟和预测,为长北气田山2段气藏高效开发提供依据。  相似文献   

1 Geological Environment of Mineralization     

YAN Fengzeng 《《地质学报》英文版》2000,74(3):554-558

Abstract The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic belt of the most famous Au‐Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension‐shear fault‐fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K‐Ar), Yanshanian granite‐porphyry (105±6 Ma, Rb‐Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow‐seated thick and big ones, which are short‐lenticular in plan and wedge‐shaped in cross section, shallow buried, large in size and high‐grade; the other is lean orebodies, which occur as parallel veins at depths. The ores are mainly of Au‐Ag polymetallic sulphide‐rich breccia type. Pyrite (limonite) is the dominant metallic mineral, with subordinate chal‐copyrite, galena, sphalerite, tenantite, native gold, electrum, native silver and argentite. The gangue minerals consist mainly of quartz and plagioclase, with subordinate carbonate minerals, alunite chalcedony and kaolin. Kaolinization is the characteristic alteration type. Sulphide minerals contain abundant trace minerals such as Cu, Pb, Ag, Sb and Hg, while in the ores Ag, Cu, Pb, Zn, As and Sb are the best indicator element assemblage of Au. The δ³⁴S(%_o) values of the ores rane from ?3.2%_o to 5.3%_o, with average ?0.102%_o. The δO H₂O(%_o) and δ(%_o) values are in the ranges from ?3.1%_o to 7.73%_o and from ?64%_o to ?90%_o respectively. The Pb isotopic compositions of the rocks and ores in this region indicate that Pb comes from three tectonic sources—upper mantle, lower crust and orogenic belt. The inclusion homogenization temperature are in the ranges of 110 to 220°C and 230 to 310°C, which suggests that the deposit formed under meso‐epithermal conditions. The ore‐forming pressures range from 6 to 32 MPa and the depths are 230 to 1200 m. In view of the above, the Puziwan gold deposit is genetically ascribed to a high‐sulphur (alunite‐kaolin) meso‐epithermal gold deposit related to subvolcanic rocks. This gold deposit formed during the Indosinian stage (245.9±0.3 Ma) and then was influenced by a thermal event in the Yanshanian stage (142.9±0.5 Ma).  相似文献   

Origin of ground fissures in the Shanxi Graben System, Northern China   总被引：3，自引：0，他引：3  

Youli Li  Jingchun Yang  Xiaomeng Hu 《Engineering Geology》2000,55(4):267-275

Since the 1950s, hundreds of ground fissures have occurred in the Shanxi Graben System in Northern China. The fissures and related subsidence and differential settlement have caused and are causing substantial damage to homes, agricultural land, roads, canals, and other infrastructure. Although generally similar in appearance, the fissures have different origins. (1) Some fissures coincide with northeast-trending faults. Trenching shows that the fissures extend into the near-surface faults, increasing vertical offset clay beds and other stratigraphic markers at depth, and therefore are probably the surface expression of fault movements. (2) Some fissures are demonstrably related to accelerated groundwater withdrawal. This is particularly apparent in Xi'an City where groundwater levels have declined by about 15 m within 4 years. (3) Other fissures owe their origin to the well-known process of ‘soil collapse’. This is particularly common in the silty loessial sediments that occur within most of the valleys that comprise the Shanxi Graben System.  相似文献   

陕西煎茶岭金矿床地质特征及其成因意义   总被引：5，自引：0，他引：5  

任小华 《矿产与地质》2000,14(2):70-75

煎茶岭金矿床产于超基性岩体与白云岩接触带的断裂构造中 ,含矿蚀变类型、矿石矿物组份以及微量元素均与超基性岩密切相关。含金矿化蚀变带的定位、矿体空间变化以及贫、富矿段的部位同时又受到多阶段活动剪切断裂控制。成矿物源主要来源于超基性岩中 ,是一处较典型的与超基性岩有关的构造蚀变岩型金矿床。  相似文献   

Monitoring the horizontal movement along the Shanxi fault zone by GPS measurement   总被引：1，自引：0，他引：1  

YAGN Guo-hua  ZHAO Cheng-kun  HAN Yue-ping  WANG Xiu-wen  GUO Yue-hong 《地震学报(英文版)》2000,13(5):499-506

IntroductionShanxi is a significant seismic activity area in North China (WANG, 1995), named as Shanxi fault zone. One can see how important it is by the name. Up to now, a large number of achievements have been obtained from the studies mainly by the geological method. In order to improve the seismic research and carry out earthquake monitoring and prediction in this area, a GPS horizontal deformation monitoring network is established along the fault from the north to the south by the Se…  相似文献