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1.
油气成藏机理研究进展和前沿研究领域 总被引:23,自引:7,他引:23
随着地质工作者刻划和认识地下地质体构成、结构的能力及研究和预测沉积盆地能量场(温度场、压力场和应力场)及其演化能力的不断提高,以流体流动和油气运移为核心的油气成藏机理研究取得了重要进展:(1)证实了油气的优势通道运移并妆步提示了优势运移通道的微观和宏观控制机制,从而使基于油气运移路径三维预测的油气藏定位预测成为可能;(2)证实了幕式快速成藏过程并初步揭示了幕式成藏的驱动机制、有利场所和地球化学识别标志,突破了油气成藏是一个缓慢渗流过程的传统模式;(3)深盆气勘探和成藏机理研究取得了进展,从而突破了背斜成藏的传统观念,使“向斜”(盆地凹陷区)成为一些盆地寻找大型天然气藏的重要场所。沉积盆地深层油气成藏过程和保存条件、活动构造背景下油气晚期快速成藏过程是油气成藏机理研究的重要前沿研究领域。 相似文献
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3.
三角洲平原上网结河的发育与聚煤作用 总被引:4,自引:4,他引:4
龙潭组上段(24#煤顶板到12#煤)是盘县地区含煤最好的层段,对该区西北部本段地层的研究表明其中发育有网结河体系。河道沉积由多层叠置的鞋带状砂体组成,湿地沉积主要由菱铁质泥质岩夹薄层板状细砂岩(决口扇沉积)和煤组成。河流的发育和聚煤作用都显示幕式性,可能主要受海平面变化的控制。网结状河道被认为是海侵期对低位下切河谷充填过程中经侧向冲裂水道并相互连通形成的;稳定、连续的厚煤层发育于河道大范围废弃后的海侵晚期,其次是高水位早期。 相似文献
4.
鹤岗盆地晚侏罗世石头河子组沉积环境及幕式聚煤作用 总被引:3,自引:0,他引:3
鹤岗盆地是一中-新生代内陆盆地,主要含煤地层上侏罗统石头河子组是一套非海相含煤地层,充填于盆地底部,自下而上可划分为三个岩性段,五个亚段和26个含煤旋回。底部第一亚段沉积期以冲积扇、辫状河环境为主;第二亚段以河流环境为主;第三亚段以河流-三角洲-湖泊环境为主;第四亚段演化为河流环境;第五亚段则以河流、冲积扇环境为主。垂向上五个亚段对应于盆地的填平补齐-扩张-稳定沉降-差异沉降-收缩五个演化阶段。富煤带位于同沉积中心的侧翼,一般含砂率60%~70%的区域含煤性最好。含煤旋回受控于盆地周期性地快-慢沉降,聚煤作用发育于每期幕式沉降的缓慢稳定沉降阶段。厚-特厚煤层都与湖泊三角洲冲积平原大面积沼泽化有关。 相似文献
5.
川西坳陷东坡沙溪庙组气藏成藏演化模式 总被引:1,自引:0,他引:1
川西坳陷东坡气藏主力产层为沙溪庙组,其圈闭类型以构造-岩性圈闭为主,多为致密砂岩储层,但断层发育,有效改善了储层物性,断砂匹配样式与构造演化对油气成藏过程有重要影响。基于前人已有的认识,通过沙溪庙组气藏成藏动力演化、气水分布特征及生烃期次分析,结合构造演化、成藏幕次等研究,认为沙溪庙组天然气成藏受构造古隆起、断砂配置、储层物性、构造演化影响,形成了“构造控向、断砂控运、储层控藏、演化控调”的成藏演化模式,同中存异,高庙子地区古构造的控制作用更为明显,而中江地区岩性控制作用占主导。沙溪庙组气藏间歇性充注具“燕山期三幕成藏,喜山期调整改造”的成藏特征,多期构造演化和较强的储层非均质性影响了含气饱和度,导致沙溪庙组气藏分布、气藏产能差异大。 相似文献
6.
Mustafa Y. Kaya Guillaume Dupont‐Nivet Jean‐Noël Proust Pierrick Roperch Laurie Bougeois Niels Meijer Joost Frieling Chiara Fioroni Sevin
zkan Altner Ezgi Vardar Natasha Barbolini Marius Stoica Jovid Aminov Mehmut Mamtimin Guo Zhaojie 《Basin Research》2019,31(3):461-486
The proto‐Paratethys Sea covered a vast area extending from the Mediterranean Tethys to the Tarim Basin in western China during Cretaceous and early Paleogene. Climate modelling and proxy studies suggest that Asian aridification has been governed by westerly moisture modulated by fluctuations of the proto‐Paratethys Sea. Transgressive and regressive episodes of the proto‐Paratethys Sea have been previously recognized but their timing, extent and depositional environments remain poorly constrained. This hampers understanding of their driving mechanisms (tectonic and/or eustatic) and their contribution to Asian aridification. Here, we present a new chronostratigraphic framework based on biostratigraphy and magnetostratigraphy as well as a detailed palaeoenvironmental analysis for the Paleogene proto‐Paratethys Sea incursions in the Tajik and Tarim basins. This enables us to identify the major drivers of marine fluctuations and their potential consequences on Asian aridification. A major regional restriction event, marked by the exceptionally thick (≤ 400 m) shelf evaporites is assigned a Danian‐Selandian age (ca. 63–59 Ma) in the Aertashi Formation. This is followed by the largest recorded proto‐Paratethys Sea incursion with a transgression estimated as early Thanetian (ca. 59–57 Ma) and a regression within the Ypresian (ca. 53–52 Ma), both within the Qimugen Formation. The transgression of the next incursion in the Kalatar and Wulagen formations is now constrained as early Lutetian (ca. 47–46 Ma), whereas its regression in the Bashibulake Formation is constrained as late Lutetian (ca. 41 Ma) and is associated with a drastic increase in both tectonic subsidence and basin infilling. The age of the final and least pronounced sea incursion restricted to the westernmost margin of the Tarim Basin is assigned as Bartonian–Priabonian (ca. 39.7–36.7 Ma). We interpret the long‐term westward retreat of the proto‐Paratethys Sea starting at ca. 41 Ma to be associated with far‐field tectonic effects of the Indo‐Asia collision and Pamir/Tibetan plateau uplift. Short‐term eustatic sea level transgressions are superimposed on this long‐term regression and seem coeval with the transgression events in the other northern Peri‐Tethyan sedimentary provinces for the 1st and 2nd sea incursions. However, the 3rd sea incursion is interpreted as related to tectonism. The transgressive and regressive intervals of the proto‐Paratethys Sea correlate well with the reported humid and arid phases, respectively in the Qaidam and Xining basins, thus demonstrating the role of the proto‐Paratethys Sea as an important moisture source for the Asian interior and its regression as a contributor to Asian aridification. 相似文献
7.
Large-scale detachment faults on mid-ocean ridges (MORs) provide a window into the deeper earth. They have megamullion on their corrugated surfaces, with exposed lower crustal and upper mantle rocks, rela- tively high residual Bouguer gravity anomaly and P-wave velocity, and are commonly associated with ocean- ic core complex. According to 30 detachment faults identified on MORs, we found that their distances to the axis mostly range from 5 to 50 km, half-spreading rates range from 6.8 to 17 mm/a, and activity time ranges from recent to 3 Ma. Most of the detachment faults are developed on the slow spreading Mid-Atlantic Ridge (MAR) and ultra-slow spreading Southwest Indian Ridge (SWIRl, with the dominant half-spreading rates of 7-13 mm/a, especially 10-13 mm/a. Furthermore, they mostly occur at the inside corner of one segment end and result in an asymmetric seafloor spreading. The detachment faults on MORs are mainly controlled by the tectonism and influenced by the magmatism. Long-lived detachment faults tend to be formed where the ridge magma supply is at a moderate level, although the tectonism is a first-order controlling factor. At the slow spreading ridges, detachment faults tend to occur where local magma supply is relatively low, whilst at the ultra-slow spreading ridges, they normally occur where local magma supply is relatively high. These faults are accompanied by hydrothermal activities, with their relationships being useful in the study of hydrothermal polymetallic sulfides and their origin. 相似文献
8.
Chronostratigraphic constraints on Middle Pleistocene faunal assemblages and Acheulian industries from the Cretone lacustrine basin,central Italy 下载免费PDF全文
9.
本文在大量实际调查资料的基础上,详细论述了天山南北麓库车山前拗陷和乌鲁木齐山前拗陷在第四纪时期主要的构造变动及形成的最新构造形迹,并利用石油地质研究的最近成果对山前拗陷中最新构造的形成、演化以及褶皱构造与基底断裂活动的关系进行了讨论。 相似文献
10.
Nikolaos P. Nikolaidis Vicki S. Nikolaidis Jerald L. Schnoor 《Aquatic Sciences - Research Across Boundaries》1991,53(4):330-345
Monte-Carlo simulations were used to assess the extent of shortterm alkalinity depressions occuring in Sierra Nevada lakes due to acidic deposition events. The Episodic Event Model (EEM) was used to simulate spring snowmelt events. Snow course data, precipitation data and lake acidification surveys were used to derive values for the EEM parameters. Spring snowmelt events were shown to have great impacts on the water quality of Sierran lakes. Lakes are likely to be most affected by the early-spring snowmelt event because the epilimnion depth is at a minimum, which indicates minimum dilution. Under annual average loading conditions, no Sierran lake has been reported as acidic although 29% of the lakes have alkalinities less than 40 µeq/L indicating a sensitivity to acidification. In simulations of early-spring snowmelt events, using present-day acidic loading conditions, it was estimated 79% ± 9% of the lakes would experience shortterm lake alkalinity depressions to levels less than 40 µeq/L. The results provided by the model simulations are valuable in establishing upper and lower limits on the extent of possible episodic acidification to lake-resources-at-risk. The most critical parameters controlling the magnitude of lake alkalinity depressions during snowmelt episodic events are a) the lake area to watershed area ratio — a measure of input loading, and b) the epilimnion volume — a measure of dilution and mixing. 相似文献