Early Palaeozoic carbonate reservoirs from the Yingshan Formation of Well block ZG‐43 in Tazhong Low Rise,Central Uplift,Tarim Basin,NW China: geological features and controlling factors     

Xiao‐dong Lan  Xiu‐xiang Lü  Hong‐feng Yu  Yan‐ming Zhu  Bo Yan 《Geological Journal》2014,49(3):256-270

Marine carbonate reservoirs, as a focus of petroleum exploration and development in China, are involved with high exploration risk and prediction difficulty owing to high heterogeneity and diversity of reservoir beds. In the Tarim Basin, NW China, carbonate reservoirs host about 38% of the whole basin's hydrocarbon resources in a large prospecting area mainly distributed in the Cambrian and Ordovician rocks in central (Tazhong) and northern (Tabei) Tarim. Recently, a better understanding has been made of the karsted weathering crust at the top of the Lower Ordovician Yingshan Formation in the northern slope area of the Tazhong Low Rise, Central Uplift, Tarim Basin. As a new frontier of exploration, oil/gas distribution and controlling factors of carbonate reservoirs in the Yingshan Formation are not clearly understood. In this work, we investigated the reservoir beds and oil/gas properties in 13 wells in Well block ZG‐43 on the No. 10 structural belt in the Tazhong Low Rise, and studied hydrocarbon accumulation characteristics with seismic and geochemical data. The Yingshan Formation in Well block ZG‐43 is mainly composed of calcarenite, dolomitic limestone, dolomite, cryptite, as low porosity and low permeability reservoir beds, with fracture‐void porosity constituting the main reservoir pore space. Oil/gas is quasi‐layer distributed beneath the unconformity between the Yingshan and Lianglitag formations to a depth of 140 m. The oil in Well block ZG‐43 is condensate with low density, low viscosity, low sulphur, low resin, low asphaltene, and high wax. The gas is 87.3% methane, generally containing H₂S. The oil/gas distribution pattern is oil in the east and gas in the west, and H₂S content in the west is lower than that in the east. The controlling factors for hydrocarbon are multi‐source supply and multi‐phase charging, interstratal karstification, hydrothermal activity, structural location and sealing condition. A structural–lithological trap is the main type of oil/gas accumulation. Oil/gas distribution was clearly affected by strike–slip faults. Oil/gas with multi‐source supply and multi‐phase charging was controlled by favourable local palaeo‐highs, and affected by later karsting and hydrothermal activity, as well as gas invasion in the Himalayan (Cenozoic) period. Under the caprock of compact limestone in the third to fifth members of the Lianglitag Formation, oil/gas migrated up along the strike–slip fault planes, and moved laterally to both sides in a ‘T’ shape, and formed large‐scale quasi‐layer condensate gas reservoirs controlled by reservoir bed quality. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

内蒙古哈达门沟金矿床成矿年代学研究     

侯万荣 《地质与勘探》2014,50(Z1):1213-1223

乌拉山-大青山成矿带为华北板块北缘重要的金多金属成矿带,其中产出有哈达门沟-柳坝沟大型金矿床,金矿床成矿时代和构造背景一直存在争议,长期被认为是中生代构造岩浆活动产物,最近在哈达门沟金矿床深部发现了与金共生的石英脉型和钾化蚀变岩型钼矿化,笔者等利用Re-Os同位素分析方法,首次对与含金黄铁矿共生的辉钼矿进行了年代学研究。4件辉钼矿Re-Os同位素等时线年龄为386.6±6.1Ma（MSWD=1.18）,加权平均年龄为386.4±2.7Ma（MSWD=0.55）,初始187Os值为-0.02±0.41 ng/g。根据辉钼矿的年龄,并且结合其它地质证据,可以推测,哈达门沟地区金矿化发生的事件可追溯到早泥盆世,属海西早期构造-岩浆活动事件,而矿区北部西沙德盖钼矿获得辉钼矿Re-Os年龄为226.4±3.3Ma,钼矿床形成于三叠纪,说明乌拉山地区内至少存在两期钼矿化,其中早期钼矿化与金矿化同时发生,且以金矿化为主,上述数据的取得,对重新认识该区金（钼）矿成矿作用及区域地质演化历史有着重要的理论和实际意义。  相似文献   

利用无人船测量系统检测钱塘江护岸工程水下块石     

毕继鑫  刘强  吴文超  占晓明 《测绘通报》2022,(10):118-123

水下块石检测与识别作为钱塘江海塘护岸工程的关键环节,对保障板桩施工工效至关重要。本文首先在研究无人船测量系统岸基通信、数据采集核心技术基础上,推导了NORBIT多波束声呐分辨率估计模型及附加块石粒径约束条件的最大波束开角、最小数据更新率、最大航速间的关系式和推荐值;然后结合钱塘江水下多波束扫测点云数据三维特性,对区域生长算法进行改进,以实现块石点云识别和提取。工程实践结果表明,优化的无人船测量系统多波束声呐参数可实现水下细小块石精准检测,能如实反映水下块石及周边微地形地貌真实情况,改进的区域生长算法能从众多河床点云数据中高效提取水下块石点云,为板桩施工提供准确的块石分布情况,具有很好的工程应用意义。  相似文献   

基于附加参数模型的自检校光束法区域网平差算法运行结果对比     

张可  王永波  袁坤  仇春平 《测绘通报》2022,(2):67-72

像点偏移是影响光束法区域网平差结果精度的主要因素之一。克服平差过程中像点偏移的影响,以提高区域网平差精度,一直受到业界高度重视。当前,克服像点偏移的常规做法是借助特定的参数模型对其进行描述,构建基于附加参数模型的自检校光束法区域网平差模型,在区域网平差的同时求解引入的参数,进而实现对系统误差的补偿。Bauer模型、Ebner模型、Brown模型、光学畸变模型是现有算法中描述像点偏移的常用模型。为了对上述4种模型的系统误差进行验证,本文首先在经典的光束法区域网平差模型基础上分别设计了与4种模型相对应的自检校光束法区域网平差模型,并予以编程实现;然后通过实例对上述4种模型的算法运行结果进行了验证、比较及分析。试验结果表明,Ebner模型和Brown模型的引入可有效提高光束法区域网平差的精度;Bauer模型的引入对小型区域网平差精度的提升更加有效;光学畸变模型的引入对区域网平差结果的精度提升作用相对较小。  相似文献   

一种基于三角形运动分块的HEVC视频编码方法     

刘梅锋  钟国韵  徐洪珍 《华东地质学院学报》2014,(3):310-315

分析了目前H.264/AVC已有的非规则运动分块方法的优缺点,根据高效率视频编码（High Efficiency Video Coding,缩写HEVC）标准,提出了三角形的帧间预测单元（Prediction Unit-PU）运动分块,相比常规的PU运动分块,它的斜边更适合一些场景中有着斜边的运动对象,从而提高编码效率。根据该三角形的运动分块形状,提出三角形PU运动分块的运动向量预测方法和运动估计方法。通过分析斜边将产生的块效应方向,相应地提出了优化HEVC滤波方法。实验结果显示,相比已有的非规则运动分块的编码方法,在编码时间平均上升23%的前提下,本算法在BD-rate方面平均降低了2.1%。  相似文献   

华北地块北缘内蒙古固阳地区早二叠世岩体的侵位深度及其构造意义   总被引：4，自引：1，他引：3       下载免费PDF全文

吴飞  张拴宏  赵越叶浩 《中国地质》2014,41(3):824-837

运用角闪石一斜长石温度计和角闪石全铝压力计估算的华北地块北缘内蒙古隆起西段固阳地区早二叠世花岗质岩体的结晶温度和侵位深度分别为679.1~728.7℃和15.6~19.8 km,表明白早二叠世以来,固阳地区至少有15.6km的地壳岩石被剥露。这一构造抬升及剥露是造成该区中—新元古代地层不连续分布及古生代—早中生代地层普遍缺失的最主要原因。岩体侵位深度与区域前二叠纪最大沉积地层厚度(13.0 km)对比结果表明,早二叠世之前,华北地块北缘已经发生了明显的褶皱或逆冲构造变形,从而导致了地壳岩石的叠覆与加厚。这一早二叠世之前的构造变形及地壳加厚可能与晚古生代期间古亚洲洋板块向华北地块下俯冲有关。  相似文献   

新疆博乐市桑金布拉克饰面石材花岗岩矿地质特征          下载免费PDF全文

王永祥  王锋 《地质找矿论丛》2014,29(4):570-578

文章阐述了新疆博乐市桑金布拉克饰面石材花岗岩矿的主要矿体形态、产状、规模和矿石的类型、品种及物理性能、放射性、荒料率、加工技术性能等质量特征,以及工作区水、工、环地质勘查,矿床开采技术条件;估算了花岗岩矿石资源/储量.  相似文献   

苏北盆地沙瓦油区滚动勘探方法研究     

邱旭明  严元锋  唐焰 《江苏地质》2014,38(1):66-71

高邮凹陷北斜坡中东部沙瓦油区是典型的复杂小断块油田,具有地下地质、地表条件复杂的特点,多年的油气勘探实践说明:不断深化石油地质理论研究,及时转变勘探思路,发展完善复杂小断块勘探配套技术是油气勘探持续突破和发现的技术支撑,坚持滚动勘探开发一体化的运行模式,是提高复杂小断块勘探效益的有效机制。  相似文献   

Geochronology and isotope analysis of the Late Paleozoic to Mesozoic granitoids from northeastern Vietnam and implications for the evolution of the South China block     

《Journal of Asian Earth Sciences》2014

In northeastern Vietnam, Late Paleozoic and Permo-Triassic granitic plutons are widespread, but their tectonic significance is controversial. In order to understand the regional magmatism and crustal evolution processes of the South China block (SCB), this study reports integrated in situ U–Pb, Hf–O and Sr–Nd isotope analyses of granitic rocks from five plutons in northeastern Vietnam. Zircon SIMS U–Pb ages of six granitic samples cluster around in two groups 255–228 Ma and 90 Ma. Bulk-rock ε_Nd (t) ranges from −11 to −9.7, suggesting that continental crust materials were involved in their granitic genesis. In situ zircon Hf–O isotopic measurements for the granitic samples yield a mixing trend between the mantle- and supracrustal-derived melts. It is suggested that the granitic rocks were formed by re-melting of the continental crust. These new data are compared with the Paleozoic and Mesozoic granitic rocks of South China. We argue that northeastern Vietnam belongs to the South China block. Though still speculated, an ophiolitic suture between NE Vietnam and South China, so-called Babu ophiolite, appears unlikely. The Late Paleozoic to Mesozoic magmatism in the research area provides new insights for the magmatic evolution of the South China block.  相似文献   

Magnetic fabric and paleomagnetism of the Middle Triassic siliciclastic rocks from the Nanpanjiang Basin,South China: Implications for sediment provenance and tectonic process     

《Journal of Asian Earth Sciences》2014

A combined magnetic fabric and paleomagnetic study has been carried out on the siliciclastic rocks gathered from a stratigraphic cross-section through the Nanpanjiang Basin, South China, in an attempt to extract the paleoflow information preserved in and, thus, constrain the possible origins of these clastic rocks. The sediments used for this study were formed by sediment-gravity flows along the southern margin of the South China block in the Middle Triassic time (ca. 245–228 Ma). The results show a normal distribution of both low field magnetic susceptibility values and natural remanent magnetization intensities, which along with the monotonic detrital framework mode, mainly comprising quartz and lithic particles, may suggest a single provenance involved in deposition of these clastic deposits. Anisotropy of magnetic susceptibility (AMS) analysis acquires primarily the sedimentary magnetic fabrics, which, in this study, reveal paleoflow directions ranging from NNW to ENE with an overall mean orientation of NE. Demagnetization on a part of samples isolates a characteristic remanent component averaged at D = 44.8°, I = 16.9°, κ = 9.7, α₉₅ = 6. 5°, n = 55, corresponding to a paleolatitude N8.6° and a clockwise rotation of ca. 45° since the Middle Triassic for the studied cross-section. This mean direction passes fold tests and is consistent with the reference direction expected from the South China block at the 95% confidence level. Restoring this ∼45° declination renders an overall northward paleoflow, which, combined with other evidence, suggests a southern provenance for these sediments during deposition in the Middle Triassic time. In terms of the early Mesozoic plate framework of southeastern Asia, a tectonic scenario is proposed here, whereby the nearly N–S convergence of the Indochina and South China blocks and its related Indosinian orogeny in the Middle Triassic caused the formation of the Nanpanjiang foreland basin, which was filled by voluminous detritus shed from the uplifted orogenic belt on its southern side.  相似文献