盆地埋藏火山机构的地质-地球物理二维精细解剖——以松南腰英台地区营城组一段为例

腰英台地区营城组一段火山岩气藏为火山机构内幕型气藏,其储层分布受火山机构控制.本文以旋回作为时间格架进行火山机构的精细划分.首先通过钻井火山岩岩性、岩相、测井资料识别出的旋回间风化壳和沉积岩夹层等地质界面,地震剖面上全区发育的连续强反射同相轴等划分火山岩的旋回.然后,在旋回内部根据不同钻井岩性、岩相的变化以及火山机构的...     

松辽盆地莺山地区营城组火山岩喷发特征研究

莺山地区火山岩的岩石类型复杂,区域分布状况不均衡,岩性横向变化快,物性致密,火山岩油气藏勘探难度大.火山岩喷发特征研究能够揭示火山岩空间展布规律和不同岩性组合的成因联系,能够为火山岩储层勘探提供有效的指导.通过钻井、测井及三维地震等资料的综合分析,将莺山地区营城组火山岩划分为三个旋回,六个期次.在精细分期次层序约束的框架下,利用相干体技术和趋势面分析法并结合火山机构在地震上的响应特征,分期次地识别火山口及火山机构,通过分析各个期次火山机构分布及演化特征开展本区火山岩喷发特征研究,总结了本区火山岩喷发规律.研究结果表明:莺山地区营城组火山岩喷发具有阶段性和差异性,各期次喷发强度差异大,总体表现为逐渐增强的趋势,旋回内部表现为先强后弱的特征.方向由东南向西北迁移,主要形成东、中、西三个大的火山机构发育带.     

松辽盆地营城组火山机构-岩相带的地震响应

松辽盆地徐家围子断陷多期次喷发的火山岩在纵向和横向上相互叠置,造成火山岩地震响应特征复杂,影响了对火山岩储层的地震预测精度和地质规律的认识.本文基于钻井和连片三维地震资料,结合区域构造认识,建立了徐家围子断陷营城组火山机构-岩相带的地震响应模式,并利用相干体和地层切片等属性分析技术实现了火山机构-岩相带的空间识别.从火...     

三位一体火山岩预测技术的建立及应用——以新僵克拉美丽气田为例

近年来火山岩气藏已成为天然气勘探开发的有利接替领域.针对克拉美丽气田火山岩气藏内幕结构复杂、非均质性强、地震反射频率低、波阻抗特征叠置严重的特点,重点开展了火山岩体解剖及内幕机构刻画、有利相带识别、储层综合预测与评价工作.形成了由源控、到体控、到相控的"三位一体"火山岩精细描述技术和基于相控反演的火山岩储层定量预测与评价技术.实践证明该技术适应于克拉美丽气田火山岩储层非均质性强,储层参数变化大的特点,并在该气田勘探开发中取得了较好的应用效果,为井位部署提供了重要的依据.     

支持向量机模型在火山岩储层预测中的应用——以徐家围子断陷徐东斜坡带为例

火山岩储层的发育程度是控制徐家围子断陷火山岩气藏的重要因素,但火山岩储层以岩性复杂、横向变化快、井间可对比性差为特点,火岩储层的准确识别、厚度的精确描述是火山岩气藏勘探开发的难题.针对这一难题,作者提出在专家优化地震属性组合的基础上确定支持向量机模型,进而预测火山岩储层厚度.该技术在实际应用中取得了良好效果,预测的火山...     

基于地震属性融合技术的火山通道识别研究

长岭龙凤山火山岩为多机构、多期次喷发叠合分布的一套火山岩地层,火山通道识别是成藏分析和油气运移等研究工作的基础,同时也影响储量计算和开发井的部署.针对深层地震资料品质较差,且难以对火山通道进行准确刻画的问题,开展针对火山通道的地震属性优选.该地区火山岩具有"低频强振幅"的特点,通过地震属性优选,提取10 Hz单频体、纹...     

Y断陷营城组火山机构特征及演化

为了搞清Y断陷营城组火山机构特征及演化规律,在区域沉积背景分析基础上,利用录井、测井及地震资料,建立了营城组火山岩旋回格架,并对火山岩演化规律进行了深入研究.将营城组划分为三大旋回,并细分为六个期次,并利用趋势面分析技术,采用井点定相、相干找型、剩余构造划界的方法,完成营城组六个期次的火山口识别,火山口规模在各个旋回时期呈弱-变强-减弱的分布规律.三大旋回火山喷发具有迁移叠置、多厚度中心的特点,不同期次火山岩喷发特征差异较大,主要表现在火山口面积、火山机构幅值、火山口分布范围以及活动强度方面.并以期次五为例,总结了火山岩相平面特征,主要发育火山口、近源相组、远源相组合火山沉积相四种类型,其中,火山口相是下一步天然气勘探的重点.     

火山地层结构特征及其对波阻抗反演的约束

火山地层是由似层状、层状和块状结构组成的复合体,其地层结构的拟合是火山岩储层地震预测的难点所在,火山地层结构模型的建立是火山岩勘探开发中首先需要解决的关键问题.通过对九台和大屯典型火山岩地层结构的解剖,分析似层状结构和层状结构特征.似层状结构地层内部的岩层倾向和倾角变化大,与地层顶底面表现为斜交.从火山机构喷发中心到远...     

松南长岭断陷火山岩亚相约束下的气层测井识别评价

松辽盆地长岭断陷营城组火山岩包括4相12亚相;优质储层主要见于爆发相热碎屑流、喷溢相上部和下部、火山通道的火山颈等4亚相.火山岩气藏普遍含CO2,部分为纯CO2气藏.基于26口重点探井的自然伽马、电阻率、声波时差和中子等测井参数分析,建立了岩相亚相-测井识别模式;进而在亚相约束下,用声波-中子-密度三种孔隙度叠置图进行...     

南中国海深水区典型火山发育地震反射特征研究

海洋油气勘探尤其是深水勘探面临着三高难题——高成本、高风险、高技术.如何对储层进行准确预测,是地球物理工作者及地球物理技术亟待解决的问题.本文对火山机构喷发机理及其地球物理特征进行分析,结合邻近工区在火山发育特征规律的认识成果,针对南中国海深水区目标区内典型火山发育,运用常规地震时间切片、剖面分析及沿层均方根振幅属性和沿层小时窗三维地震镂空显示等技术,分析了目标火山发育情况、火山岩喷溢情况、地震反射特征及岩相分布,并建立了该类型火山发育特征、岩相分布规律以及空间展布规律及变化特征的认识.本文的研究成果为该地区准确识别火山发育及预测其分布规律提供了参考,尤其是在钻井少的情况下进行地质异体常识别和储层预测,有利于该地区石油天然气勘探工作以及区域地质认识.     

The catalogue of Quaternary volcanoes of the Greater Caucasus based on geochronological,volcanological and isotope-geochemical data

A catalogue of Quaternary volcanoes of the Greater Caucasus has been compiled based on recent geological, petrological-geochemical and isotope-geochronological data obtained in the last decades. This catalogue provides insight into the evolution of the youngest magmatism in this part of the Alpine-Himalayan fold belt at the modern level of knowledge. The catalogue is given as a set of tabular data on 74 volcanic edifices that have been found and described in literature in varying detail, including their coordinates, absolute height, type of edifice and the predominant type of eruption, age, as well as main petrographic, isotope-geochemical characteristics, and the chemical composition of the products of magmatic activity. For the sake of convenience, the volcanoes of the Kazbek and Elbrus neovolcanic areas representing two main areals of young magmatism at the Greater Caucasus are described separately. In addition, data on the Kazbek area are grouped by traditionally distinguished volcanic centers. Text presents general information on the Quaternary volcanic activity within the Greater Caucasus, its geochronology, spatiotemporal distribution, and petrogenesis of the youngest volcanic rocks.     

Volcano collapse promoted by progressive strength reduction: new data from Mount St. Helens

Rock shear strength plays a fundamental role in volcano flank collapse, yet pertinent data from modern collapse surfaces are rare. Using samples collected from the inferred failure surface of the massive 1980 collapse of Mount St. Helens (MSH), we determined rock shear strength via laboratory tests designed to mimic conditions in the pre-collapse edifice. We observed that the 1980 failure shear surfaces formed primarily in pervasively shattered older dome rocks; failure was not localized in sloping volcanic strata or in weak, hydrothermally altered rocks. Our test results show that rock shear strength under large confining stresses is reduced ∼20% as a result of large quasi-static shear strain, as preceded the 1980 collapse of MSH. Using quasi-3D slope-stability modeling, we demonstrate that this mechanical weakening could have provoked edifice collapse, even in the absence of transiently elevated pore-fluid pressures or earthquake ground shaking. Progressive strength reduction could promote collapses at other volcanic edifices.     

松辽盆地白垩系营城组隐伏火山机构物理模型和地震识别

将火山机构分为火山口-近火山口相 (CNCF)、近源相 (PF)和远源相 (DF)三个相带.露头揭示这三个相带的倾角范围为：CNCF-40～70°,PF-25～45°,DF-20～35°.这三个相带的裂缝线密度为：CNCF-10～30条/m,PF-3～25条/m,DF-2～11条/m.这三个相带的相干值的关系为：CNCF相似文献   

Was a dacite dome implicated in the 9,500 <Emphasis Type="SmallCaps">b.p.</Emphasis> collapse of Mt Ruapehu? A palaeomagnetic investigation

Constraining the process by which volcanoes become unstable is difficult. Several models have been proposed to explain the driving forces which cause volcanic edifices to catastrophically collapse. These include models for destabilisation of volcanic flanks by wedging due to dyke intrusion and the weakening of mechanical properties by pressurisation of pore fluids. It is not known which, if any, of the models are relevant to particular sector collapse events. Recent developments in the palaeomagnetic estimation of emplacement temperatures of volcaniclastic rocks have shown that even relatively low emplacement temperatures can be recorded by volcaniclastics with high fidelity. We have carried out a palaeomagnetic study of emplacement temperatures to investigate the role of igneous activity in the initiation of the 9,500 b.p. Murimotu sector collapse of Mt Ruapehu, New Zealand. This debris avalanche deposit has three fades which are stratigraphically superimposed, and the lowermost fades contains three lithological assemblages representing different segments of the edifice which were transported with little internal mixing within the flow. We have determined that some of the dacite-bearing assemblage 1, fades 1 was hot (∼350 °C) during transport and emplacement, whereas none of the other lithological assemblages of fades contained hot material. Our interpretation is that a dacite dome was active on the ancient Ruapehu edifice immediately prior to the Murimotu sector collapse. The partially cooled carapace of the dome and material shed from this part was incorporated into the avalanche deposit, along with cold lavas and volcaniclastics. We have not found evidence for incorporation of material at or close to magmatic temperatures, at least in the sampled locations. Our palaeomagnetic work allows us to develop a comprehensive, new palaeomagnetic classification of volcaniclastics. Published online: 25 January 2003 Editorial responsibility: D. Dingwell     

松辽盆地营城组火山机构相带地震-地质解译

将火山机构按距火山口1远近划分为火山口-近火山口、近源和远源三个相带.营城组火山机构相带有6种地震相类型,分别是丘状、透镜状、穹状、池塘状、楔状和席状地震相.丘状、透镜状和穹状均见于火山机构中心相带,但所代表的优势岩相不同,分别与爆发相、喷溢相和侵出相对应.池塘状和楔状均为近源相带,但前者以喷溢相辫状熔岩流为主,而后者...     

Volcanic facies architecture of an intra-arc strike-slip basin, Santa Rita Mountains, Southern Arizona

The three-dimensional arrangement of volcanic deposits in strike-slip basins is not only the product of volcanic processes, but also of tectonic processes. We use a strike-slip basin within the Jurassic arc of southern Arizona (Santa Rita Glance Conglomerate) to construct a facies model for a strike-slip basin dominated by volcanism. This model is applicable to releasing-bend strike-slip basins, bounded on one side by a curved and dipping strike-slip fault, and on the other by curved normal faults. Numerous, very deep unconformities are formed during localized uplift in the basin as it passes through smaller restraining bends along the strike-slip fault. In our facies model, the basin fill thins and volcanism decreases markedly away from the master strike-slip fault (“deep” end), where subsidence is greatest, toward the basin-bounding normal faults (“shallow” end). Talus cone-alluvial fan deposits are largely restricted to the master fault-proximal (deep) end of the basin. Volcanic centers are sited along the master fault and along splays of it within the master fault-proximal (deep) end of the basin. To a lesser degree, volcanic centers also form along the curved faults that form structural highs between sub-basins and those that bound the distal ends of the basin. Abundant volcanism along the master fault and its splays kept the deep (master fault-proximal) end of the basin overfilled, so that it could not provide accommodation for reworked tuffs and extrabasinally-sourced ignimbrites that dominate the shallow (underfilled) end of the basin. This pattern of basin fill contrasts markedly with that of nonvolcanic strike-slip basins on transform margins, where clastic sedimentation commonly cannot keep pace with subsidence in the master fault-proximal end. Volcanic and subvolcanic rocks in the strike-slip basin largely record polygenetic (explosive and effusive) small-volume eruptions from many vents in the complexly faulted basin, referred to here as multi-vent complexes. Multi-vent complexes like these reflect proximity to a continuously active fault zone, where numerous strands of the fault frequently plumb small batches of magma to the surface. Releasing-bend extension promotes small, multivent styles of volcanism in preference to caldera collapse, which is more likely to form at releasing step-overs along a strike-slip fault. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Seismic model and geological interpretation of the basement beneath the Doupovské Hory Volcanic Complex (NW Czech Republic)

The Doupovské Hory Volcanic Complex (DHVC) is the best-preserved large volcanic suite of the Cenozoic intraplate volcanism in the Bohemian Massif. However, many uncertainties remain in the geological setting of its basement. In summer 2008, two seismic refraction profiles ran across this area to reveal the depth of the volcanic rocks and the underlying geological structure.     

The Fekete-hegy (Balaton Highland Hungary) “soft-substrate” and “hard-substrate” maar volcanoes in an aligned volcanic complex – Implications for vent geometry,subsurface stratigraphy and the palaeoenvironmental setting

The Fekete-hegy volcanic complex is located in the centre of the Bakony Balaton Highland Volcanic Field, in the Pannonian Basin, which formed from the late Miocene to Pliocene period. The eruption of at least four very closely clustered maar volcanoes into two clearly distinct types of prevolcanic rocks allows the observation and comparison of hard-substrate and soft-substrate maars in one volcanic complex. The analyses of bedding features, determination of the proportion of accidental lithic clasts, granulometry and age determination helped to identify and distinguish the two types of maar volcanoes. Ascending magma interacted with meteoric water in karst aquifers in Mesozoic carbonates, as well as in porous media aquifers in Neogene unconsolidated, wet, siliciclastic sediments. The divided basement setting is reflected by distinct bedding characteristics and morphological features of the individual volcanic edifices as well as a distinct composition of pyroclastic rocks. Country rocks in hard-substrate maars have a steep angle of repose, leading to the formation of steep sided cone-shaped diatremes. Enlargement and filling of these diatreme is mainly a result of shattering material by FCI related shock waves and wall-rock collapse during downward penetration of the explosion locus. Country rocks in soft-substrate maars have much shallower angles of repose, leading to the formation of broad, bowl shaped structures or irregular depressions. Enlargement and filling of these diatremes is mainly the result of substrate collapse, for example due to liquefaction of unconsolidated material by FCI-related shock waves, and its emplacement by gravity flows. The Fekete-hegy is an important example illustrating that the substrate of a volcanic edifice has to be taken into account as an important interface, which can have major control on phreatomagmatic eruptions and the resulting characteristics of the volcanic complex.