南黄海盆地白垩系油气赋存特征与2类烃源岩

南黄海盆地是中国海域历经54年勘探至今尚未实现工业油气发现的唯一大型含油气盆地,特别是29年前发现的白垩系黑色页岩含轻质油,属于页岩油范畴。分析了南黄海盆地白垩系勘探研究现状,提出白垩系主要分布于盆地北部,有8口井钻遇,K1系红浦口组,K2系黑泰州组,与苏北盆地近似;在最新地震测线上表现为顶蚀,与古/新近系及下伏侏罗系均呈不整合接触,斜层状分布,残留沉积,部分构成次凹的特征。通过近海灵山岛露头调查、剖面实测和包括常规生油岩有机质丰度、类型、成熟度、等离子质谱、U-Pb同位素年龄等测试,发现下白垩统多套深灰黑色含煤泥岩层,发育Ⅰ型和Ⅲ型干酪根,自由烃0.02~0.07mg/g或为零,生油潜力0.06~0.03mg/g或为零,残留有机碳1.85%~1.99%或0.70%~0.84%,氧指数4及超过10,属于2类烃源岩,分别生烃和二氧化碳气。总体认为南黄海盆地白垩系具有一定资源前景,值得开展深入分析。     

灵山岛沉积物软变形构造特征

为了研究灵山岛的沉积物软变形构造特征,利用野外露头考察、沉积岩石学、地球化学等方法,根据形态学、驱动力、沉积物液化及变形机制等因素进行了深入分析。识别出多种类型沉积物软变形:卷曲变形、液化底辟、负载构造、挤入构造、液化角砾岩、球—枕构造、泄水构造,并详细描述了这些沉积物软变形的表面特征和分布规律。依据各种地质记录,本区构造活动频繁、附近的五莲—烟台断裂于早白垩世是最活跃的时期,认为本文所描述的沉积物软变形是由地震触发引起的。根据不对称负载构造受横向剪切力分析,验证了吕洪波[1]推断早白垩世盆地古斜坡方向SE高NW低的观点。早白垩世巨厚白色凝灰岩可能系本区存在深切至下部岩浆囊的大断层所致,在这个深切过程中诱发一系列地震活动与沉积物的软变形。     

西沙中新世化石仙掌藻礁矿物岩石孔渗层特征及成因模式

Halimeda is one of the major reef-building algas in the middle Miocene of Xisha, and one of the significant reefbuilding algas in the algal reef oil and gas field of the South China Sea. However, there have been few reports regarding the characteristics of mineral rocks, reservoir porosity and permeability layers, and sedimentationdiagenetic-evolution of fossil Halimeda systems. The present paper briefly introduces the relevant studies on chlorophyta Halimeda and the research status of oil and gas exploration. Through the 1 043 m core of the Xichen-1 well, we studied the characteristics of the mineral rocks and porosity and permeability of the middle Miocene Halimeda of the Yongle Atoll, identified and described the segments of fossil Halimeda, and pointed out that most of the segment slides are vertical sections in ovular, irregular or long strips. The overwhelming majority of these fossil Halimeda found and studied are vertical sections instead of cross sections. In this paper, knowledge regarding the cross sections of fossil Halimeda is reported and proven to be similar with the microscopic characteristics of modern living Halimeda; fossil Halimeda are buried in superposition; it is shown that there are different structures present, including typical bio-segment structure, and due to its feature of coexisting with red alga, tying structure, twining structure and encrusting structure are all present; and finally, it is suggested to classify the fossil Halimeda into segment algal reef dolomites. In addition, all of the studied intervals are moderately dolomitized. Secondary microcrystalline-dolosparite dominates the original aragonite raphide zones,and aphanitic-micrite dolomite plays the leading role in the cortexes and medullas; in the aragonite raphide zones between medulla and cysts, secondary dissolved pores and intercrystalline pores are formed inside the segments, and algal frame holes are formed between segments; therefore, a pore space network system(dissolved pores + intragranular dissolved pores—intercrystalline pores + algal frame holes) is established. Segment Halimeda dolomite has a porosity of 16.2%–46.1%, a permeability of 0.203×10–3–2 641×10–3 μm2, and a throatradius of 23.42–90.43 μm, therefore it is shown to be a good oil and gas reservoir. For the reasons mentioned above, we suggest building the neogene organic reef-modern reef sedimentation-diagenetic-evolution models for the Xisha Islands.     

我国油气层序地层学进展及在碳酸盐岩油气勘探中的应用

结合"全国第5届油气层序地层学"学术研讨会的相关内容,阐述了我国油气层序地层学理论和技术方法研究的进展;介绍了有关坳陷型盆地、断陷型盆地和深水扇特别是海相碳酸盐岩—生物礁系统油气层序地层学领域等重要研究成果;指出其现实意义特别重要,对于我国各大油气区及海洋深水油气勘探及可持续发展具有明显的推动作用。     

莺歌海盆地崖13—1气田成烃地震相及有机相

本文讨论了莺歌海盆地崖13—1气田一套典型三角洲相沉积体系及其地震相模式.提出该气田巨大天然气储量具多源成因和多产层的观点.同时对沉积物有机相,有机质稀化和天然气富集的规律进行探索.最后提出莺歌海成气模式的设想,并认为该盆地具有新的油气勘探前景.     

西沙群岛海滩岩类型及其油气地质意义

介绍了西沙群岛现代生物礁最新科考成果,在数十个岛屿上发现海滩岩,划分为固结海滩岩、高位海滩岩、坍塌破坏型海滩岩、侵蚀破坏型海滩岩和侵蚀型海滩岩5种类型;描述了它们的手标本特征、赋存分布及岩石类型和作为油气储层的价值;指出甘泉岛淡水资源的存在归因于海滩岩的胶结致密程度。     

东海地球动力学环境与过程的同位素证据及盆地动力学模式

在东海地球动力学环境与过程研究现状分析基础上,讨论了采自盆地东西部油气钻井玄武岩样品的岩石化学、微量元素和同位素测试分析的成果,阐述了玄武岩岩石结构与岩石成分特征,计算岩浆起源深度与岩浆起源温度。通过岩浆源区地幔性质与深部过程分析,指出Sm-Nd、Pb-Pb、Nd-Pb同位素体系反映的深部地幔流体具有古生代向新生代转型的双重特征,与古生代地幔岩浆来源具有较明显亲和性,其中既有古老地幔物质存在,又有新生地幔物质参与,表明研究区地壳深部流体活动十分频繁。结合海洋一期"863"双船折射大剖面有关地质-地球物理解释成果的综合分析认识,提出了盆地地球动力学成因模式。     

中国海海陆之变迁

本文简要讨论了中国海海陆变迁的历程和研究意义，提出了“年轻的黄、渤海”、“较为古老的南海”和东海介于其间的认识。     

西沙群岛地下淡水及其相关因素探讨

本文围绕西沙群岛生物礁地下淡水的来源、可能成因和赋存条件进行了初步讨论，提出了有待深入研究的课题。