普光地区长兴组生物礁储层分布预测

川东北普光地区长兴组生物礁具备广阔的勘探潜力。文中对比了普光和元坝地区生物礁的生长模式,分析了生物礁及储层的地质特征,总结了礁相白云岩储层的纵横向分布规律。在此基础上,利用测井资料、地震资料,进行生物礁模型地震正演,确定生物礁及储层的地震相识别模式;采用古地貌分析确定储层发育的有利沉积相带,并通过沉积相带的展布和适宜的时窗选取规避不利岩性(泥灰岩)的干扰,再使用相面法、属性分析、波阻抗反演对有效储层进行精细预测,建立了一套适用于普光地区的生物礁储层地震预测方法,定量预测了普光地区长兴组生物礁储层的分布,认为生物礁储层垂向上主要发育于礁盖,横向上主要分布在台地边缘的狭窄条带上。预测结果与钻井资料、礁相储层分布规律相符,证明了方法的有效性。     

油气藏成藏期构造应力场与油气聚集

本文重点讨论桥口油田成藏期构造应力场研究方法和分布规律,论述了构造应力场对构造体系、沉积体系及油气形成和分布的控制作用;提出了NNE向主导构造控制研究区油气的形成和分布,预测了有利含油气区。     

兴隆气田长兴组生物礁储层预测研究

针对四川盆地兴隆气田长兴组隐蔽海相生物礁气藏空间形态及有利储层预测难的问题,首先建立生物礁体地震正演模型,揭示生物礁体独特的"外形上凸、内部波形杂乱、反射波组增多、频率降低"地震响应模式,指导优选地震几何形态类、波组统计类、频率类属性开展分析,并通过多属性聚类融合刻画生物礁相储层边界形态;然后应用中子拟声波约束模型迭代反演方法预测储层厚度;进一步开展纵波速度与孔隙度交会分析,应用非线性方程转换速度反演成果预测储层孔隙度;最终通过计算储能系数,探寻储层厚度与孔隙度最优匹配特征,定量预测礁相有利储层分布特征。该预测方法揭示了生物礁储层空间展布特征,提高了预测精度,对礁相储层预测研究具有一定的借鉴意义。     

阿联酋下白垩统舒艾巴组生物礁沉积模式

本文在露头分析和钻井资料研究的基础上,结合区域地质背景,对阿联酋地区下白垩统舒艾巴组生物礁沉积特征进行了分析,确定了该区生物礁的沉积模式及有利储层发育相带。舒艾巴组沉积时期,具备优越的生物礁发育条件,造礁生物主要为厚壳蛤。研究区舒艾巴组碳酸盐台地具有"缓斜坡镶边台地"沉积特征,自盆地边缘向盆地内部,依次发育浅海低能碳酸盐陆架、浅海高能碳酸盐陆架、深水低能碳酸盐陆架、盆地斜坡相和深海盆地相。浅海高能碳酸盐陆架-盆地斜坡相带为生物礁发育带及油气富集区。其中浅海陆架边缘的高能相带为厚壳蛤生物礁发育的最有利区域,储层物性最好,厚壳蛤礁主要形成于早期存在的藻类粘结灰岩台地高点和台地边缘,礁核和礁前为优质储层发育带。研究该区生物礁的沉积模式与分布规律,对该区生物礁储层油气勘探具有重要的指导意义。     

塔里木盆地塔中隆起奥陶系碳酸盐岩油气运聚主控因素及成藏模式

从多元地质条件及其空间匹配关系角度出发,综合地质剖析及地球化学示踪等方法,对塔里木盆地塔中隆起奥陶系油气输导体系、运移方向及分布特征等进行的精细研究。结果显示:断裂、源储接触关系及盖层等共同控制着油气垂向运移的距离及层位;构造背景、不整合面、渗透性输导层、断裂的配置关系等控制着油气侧向运移的方向、通道和距离;海平面升降旋回、优质储层的配置关系控制着油气垂向聚集层位及平面分布规律。进一步结合研究区烃源岩条件、储层类型等研究成果,基于源储纵向接触关系及油气垂向运移距离,目的层油气成藏模式可分为近源混合成藏模式与远源混合成藏模式;根据油气来源区域及油气横向运移距离,又可分为内部源岩叠加混合成藏模式与内外部源岩交叉混合成藏模式。     

元坝长兴组超深层生物礁大气田优质储层发育机理

通过系统开展元坝气田长兴组超深层生物礁储层岩石学与岩石地球化学分析,结合碳酸盐岩溶蚀动力学模拟实验,以及储层古压力恢复,揭示了元坝超深层生物礁优质储层的发育保存机理。研究表明,早期暴露溶蚀、浅埋藏白云岩化是基质孔隙发育的基础,储层深埋引起的古油藏原油裂解导致的超压水力破裂缝的形成,是储层渗透性改善的关键,"孔-缝耦合"共同控制了超深层优质储层的发育。在此基础上,构建了生物礁非均质"孔-缝双元结构"储层模型,为生物礁储层预测奠定了理论基础。     

柴达木盆地西部古近纪一新近纪湖相生物礁的发现及意义

在柴达木盆地西部古近纪和新近纪地层中发育了典型的湖相生物礁,可以分为由基质支撑的叠层石礁、凝块礁和骨架支撑的藻礁3大类型,并对每种类型中亚类的特征和建造生物进行了简要介绍。生物礁孔隙度高、渗透性好,是优质储层。孔隙类型丰富多样,主要有骨架孔隙、体腔孔隙、粒内孔隙、溶孔等10种孔隙类型。生物礁的地震响应和测井曲线特征明显,在研究取心井段生物礁地球物理响应特征的基础上可以有效的识别和预测生物礁。综合应用古生物分析、孢粉分析、同位素分析、古地磁分析、地球化学分析和地球物理特征分析等技术手段,并结合生物礁发育的沉积条件和构造背景,初步探讨了生物礁对柴达木盆地古气候、古地理位置、古构造、古水介质、古沉积环境和青藏高原的隆升等方面的研究意义以及对油气勘探方面的意义。     

柴达木盆地西部古近纪—新近纪湖相生物礁的发现及意义

在柴达木盆地西部古近纪和新近纪地层中发育了典型的湖相生物礁,可以分为由基质支撑的叠层石礁、凝块礁和骨架支撑的藻礁3大类型,并对每种类型中亚类的特征和建造生物进行了简要介绍。生物礁孔隙度高、渗透性好,是优质储层。孔隙类型丰富多样,主要有骨架孔隙、体腔孔隙、粒内孔隙、溶孔等10种孔隙类型。生物礁的地震响应和测井曲线特征明显,在研究取心井段生物礁地球物理响应特征的基础上可以有效的识别和预测生物礁。综合应用古生物分析、孢粉分析、同位素分析、古地磁分析、地球化学分析和地球物理特征分析等技术手段,并结合生物礁发育的沉积条件和构造背景,初步探讨了生物礁对柴达木盆地古气候、古地理位置、古构造、古水介质、古沉积环境和青藏高原的隆升等方面的研究意义以及对油气勘探方面的意义。     

开江—梁平台内海槽东段长兴组白云岩储层沉积-成岩系统研究

为了指导部署四川盆地白云岩储层中钻井,在油气钻井岩心观察与描述、野外剖面实测和样品采集的基础上,结合镜下薄片鉴定、X衍射、物性和地球化学特征分析,对开江—梁平台内海槽东段长兴组白云岩储层的沉积-成岩系统进行了深入研究。认为台地边缘生物礁和台地边缘浅滩为最重要的储集相带,颗粒白云岩、生物礁白云岩和晶粒白云岩为最主要的储集层岩性,晶间孔、晶间溶孔和超大溶孔为目的层最有效的储集空间,孔洞缝复合型储层为目的层最优质的储集类型。综合分析认为,长兴组沉积-成岩系统与白云岩储层在时空上具有良好的耦合关系,台地边缘生物礁和台地边缘浅滩相控制了白云岩储层的区域分布范围,而不同成岩系统对储层的贡献程度不同。其中:地层封存卤水与混合热卤水成岩系统是储层形成的基础与关键,地层封存卤水形成低孔低渗的孔隙型Ⅲ类储层,混合热卤水形成中孔中渗的孔洞型Ⅱ类储层;构造热液成岩系统对储层贡献最大,并形成高孔高渗的孔洞缝复合型Ⅰ类优质储层。     

复式油气田与沉积相研究——以济阳坳陷为例

该文以济阳坳陷为例论述了陆相盆地沉积学研究及油气勘探的历程,探讨了沉积学研究与油气勘探的密切关系。礁灰岩的发现及粒悄碳酸盐岩分布规律的预测、河流相分布模式的识别、湖相侧向加积理论的深化、深湖浊积岩系列的建立以及箕状凹陷陡坡砂砾岩体的精细研究,都极大地扩大了油气勘探的领域,奠定了寻找大、中型油气田的理论基础,丰富了复式油气区勘探理论。     

中国二叠纪生物礁的研究现状及新进展

对我国二叠纪生物礁的类型、演化规律及研究方法进行了系统的总结。按造礁生物种类的不同可将二叠纪生物礁分为珊瑚礁和海绵礁;按古地理位置的不同可分为岸礁、台地边缘礁及点礁。生物礁研究的方法包括传统方法、结合成岩作用的方法、定量地层学方法、地球化学方法及地球物理方法等。最后对东昆仑地区最新发现的生物礁作了简单的介绍。     

Study on the application of a comprehensive technique for geological prediction in tunneling

The technique of geological prediction, based on which geological conditions can be known in advance to improve construction progress, is widely adopted during tunnel excavation. Because of the problems associated with current, single-method prediction techniques, a comprehensive technique combining engineering geophysical exploration with engineering geology is proposed in this study. This method could make excavation more economical and safer by improving the accuracy of such predictions. It uses engineering geophysical exploration measures such as tunnel seismic prediction (TSP) to detect the geological conditions ahead, and measures the investigation and deduces the precise results either in the tunnel or on the surface. Compared with single-method techniques, its advantages include high resolution, speed, ease of use, and low cost. By comparing the application of the various techniques and a successful example of application of technique TSP203 with the measures of investigation and deduction in engineering geology, we show the superiority of the proposed comprehensive method and its favorable prospects. This contribution also provides a new concept for the development of tunnel geological prediction techniques.     

Bucket structure in carbonate accumulations of the Maldive, Chagos and Laccadive archipelagos

Peritidal platforms rimmed by reefs, and raised reefs rimming deep lagoons, are characteristic morphologies of the tropical carbonate factory; their geometry contrasts sharply with the seaward-sloping shelves of siliciclastic margins. The structure has been compared to a bucket—stiff reef rims holding a pile of loose sediment. Remote-sensing data from the Maldive, Chagos and Laccadive archipelagos of the Indian Ocean show that ring reefs with bucket structure are the dominant depositional pattern from patch reefs of tens of meters to archipelagos of hundreds of kilometers in diameter, that is, over more than 4 orders of magnitude in linear size. Over 2.5 orders of magnitude, the bucket structures qualify as statistical fractals, exhibiting self-similar patterns and size distributions following power laws. However, most regional or genetic subsets of the data follow lognormal distributions and small subsets of lagoon reefs exhibit exponential distributions. Seismic data and boreholes in the Maldives indicate that the bucket has been a dominant depositional motif since the Oligocene. Ecological and hydrodynamic studies on modern reefs suggest that the bucket structure is a form of biotic self-organization: the edge position in a reef is favored over the center position because bottom shear is higher and the diffusive boundary layer between reef and water thinner. Thus, the reef edge has easier access to nutrients and is less likely to be buried by sediment. The bucket structure reflects these conditions. Karst processes have accentuated the surface relief of the buckets, particularly in the late Quaternary.     

湖南慈利晚二叠世海绵礁与珊瑚礁的古生态研究

中国南方晚二叠世生物礁分布广泛，但绝大多数属于海绵礁，湖南慈利晚二叠世除发育有海绵礁外，还有至今为止发现的世界上发育最好的古代珊瑚礁，而且海绵礁与珊瑚礁在同一条带上连续分布；因此是研究海绵礁与珊瑚礁古生态关系十分理想的场所，通过对慈利晚二叠世海绵礁及珊瑚礁内部造礁生物群落、沉积相特征，礁化演化序列及成岩作用特征等的分析和对比来研究它们之间的生态关系，发现其中的海绵礁为台地边缘礁，而珊瑚礁则应属于岸     

The Fugløy Reef at 70°N; acoustic signature,geologic, geomorphologic and oceanographic setting

This is the first in-depth study of a cluster of cold-water coral reefs, the Fugløy Reefs, found at 70°N on the Norwegian margin. Combining high-resolution seismic reflection data, side-scan sonar, video-images, and oceanographic measurements reveals the geologic, geomorphologic and oceanographic setting in which the reefs occur. The reefs consist mainly of the scleractinian ahermatypic Lophelia pertusa, and exist below the thermocline at water depths between 140  m and 190 m. The reefs appear as cone-shaped, acoustically transparent features on seismic reflection data, consistently located in places characterized by the availability of hard substrate, high relief, and periodical exposure to high tidal currents (>30 cm/s). These currents transport water of the Norwegian Atlantic Current to the reefs from an area with fluid expulsion-related pockmarks. The spatial relationship between reef, pockmark locations, and current directions suggests that seepage of biogenic gas might be a catalyst to reef growth. With a height of more than 40 m some of the Fugløy reefs are among the highest reported from the Norwegian Margin. This indicates highly favourable growth conditions, and conservative estimates indicate a net growth rate for the reefs of ~5 mm/year. We expect that cold-water reefs will be found further north along the Barents Sea margin as general awareness on the geophysical signature and appearance of the reefs increases, because all known factors involved in reef establishment and growth are within the required intervals also further north.     

川东黄龙场构造上二叠统长兴组生物礁特征与潜伏礁预测

通过黄龙场4口上二叠统长兴组钻井岩心剖面和其他井相关资料的详细研究,证实黄龙1井、4井有生物礁, 黄龙3井、5井无生物礁;生物礁由海绵障积岩组成,属于台地边缘礁。针对礁与非礁地层物性差异小,非均质性强, 多解性问题突出的特点,运用地质、测井和地震相结合的预测方法,确定了黄龙1井区的生物礁气藏发育边界,并发现了黄龙5井西侧生物礁气藏,为川东生物礁预测提供了一种实用的方法。     

万安盆地生物礁及碳酸盐台地的发育演化及控制因素

生物礁及碳酸盐台地是南海南部重要的油气储层之一,但目前对万安盆地生物礁的识别及碳酸盐台地沉积相带的划分尚不够深入.基于钻井和地震数据对该区的生物礁及碳酸盐台地进行了精细刻画,万安盆地中生物礁及碳酸盐台地的发育可分为4个演化阶段:早中新世时期,碳酸盐台地初始发育,台地规模小、数量少,零星分布于盆地中部;中中新世台地发育进入繁盛阶段,主要分布于北部隆起、中部隆起及隆起周缘的斜坡之上,横向上呈东、西带状展布,此时期的生物礁以台地边缘礁和块状礁为主;至晚中新世时期,碳酸盐台地开始衰退,而生物礁类型全、数量多,包括台地边缘礁、块状礁、塔礁、点礁等;上新世以来,生物礁及碳酸盐台地全面被淹没,盆地内部不再有生物礁及碳酸盐台地的发育.构造作用和相对海平面变化控制了碳酸盐台地的发育演化过程,古近纪基底断裂产生的地形控制了生物礁及碳酸盐台地初始发育位置及后期发育的空间分布,晚中新世以来的快速沉降和相对海平面变化控制了台地的衰退及淹没过程.      

华南二叠纪生物成礁模式探讨

二叠纪生物礁广泛发育于我国南方碳酸盐岩地区。鉴于许多研究者从成礁的外部环境因素来探讨生物礁的发育模式,笔者从我国南方二叠纪生物礁的内部成礁因素分析,即从主要造礁生物——钙质海绵和钙质藻类等的生物学和生态学特征、埋藏和保存特点方面进行分析,继而提出了华南二叠纪海绵礁的成礁模式。此模式不同于其它地质历史时期生物礁的成礁模式     

On facies belts and facies mosaics: Holocene isolated platforms,South China Sea

Although the general criteria for recognition and environmental interpretation of different carbonate facies are well‐established, a predictive understanding of the areal extent and spatial patterning of facies bodies and why they might organize into facies belts or facies mosaics is poorly constrained. To explore patterns and process dynamics of facies on isolated carbonate platforms, quantitative analysis of thematic maps derived from remote sensing images of 27 Holocene atolls of the Paracel and Spratly chains in the South China Sea explores variability within and among platforms. On these systems, most annular shelf‐margin reefs are less than 500 m wide on both chains; inboard of the reefs, reef sand aprons range up to 500 m (Spratlys) and 1000 m (Paracels) wide. Around individual platforms, Spratly Chain sand apron widths are wider to the north‐west, whereas apron widths in the Paracel Chain are more symmetrical; collectively, data indicate log‐normal width‐exceedance probability distributions. Platform‐interior patch reefs include area‐exceedance probability distributions and gap size distributions (lacunarity) consistent within chains, but distinct between the chains. To understand the processes underlying distinct distributions, simulations explored distinct growth scenarios. Results suggest that differences may represent distinct process classes: proportional growth processes with multiplicative random effects (reef sand aprons – belts), versus non‐linear, size‐proportional growth of randomly aged and distributed elements (patch reefs – mosaics). The probabilistically distinct sizes and spatial patterns of geomorphic elements within these general process classes are interpreted to represent ‘variations on themes’ related to the different impacts of tropical storms, winter cold fronts and circulation in each chain. The results highlight fundamentally different growth patterns impacting the sizes and distribution of facies belts and mosaics on isolated carbonate platforms. Because these types of bodies ultimately construct stratigraphy, the themes could be applied to understand and predict variability in the architecture of subsurface reservoir analogues.     

Contradicting Barrier Reef relationships for Darwin’s Evolution of reef types

The Darwinian progressive subsidence model for the evolution of fringing reefs, barrier reefs and atolls has been generally accepted following the indisputable proof of subsidence provided by drilling results in the Pacific. Nonetheless, there are data that do not fit the expectations of the model, such as the similar lagoon depths of barrier reefs and atolls as opposed to the subsidence theory’s implicit prediction that atolls should have significantly greater depths. In contrast, a great deal of evidence supports the influence of meteoric solution on barrier reef morphology. For example, the maximum lagoon depth of 56 modern barrier reefs is statistically correlated with the lagoon catchment area for modern annual rainfall. These modern rainfall patterns would seem to be a reasonable proxy for relative geographic differences in glacial lowstand rainfall, even though the absolute amounts of such rainfall are unknown. The correlation therefore suggests the importance of Pleistocene subaerial solution in contributing to barrier reef morphology. Further support for antecedent influence occurs in the form of barrier reef passes in which the depth of the reef pass is correlated with onshore drainage volumes. On a larger scale, the Cook Island of Mangaia provides evidence that solution can produce barrier reef morphology independent of reef development. In contrast, there are no examples of the subsidence-predicted lagoon transition of fringing reefs to barrier reefs to atolls. Moreover, the common occurrence of fringing reefs within barrier reefs negates subsidence as a causal factor in their ‘presumed progressive evolutionary development. Consequently, the evidence to date suggests that a solution morphology template has been accentuated by reef construction to produce the diagnostic barrier reef morphology we see today. The importance of subsidence would seem to be in accounting for the overall thickness of the resulting carbonate caps of oceanic examples and in contributing to lagoon depth variation among the larger continental entities.

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