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11.
The generation of natural gases is much more complicated in comparison with liquid petro-leum in that natural gases could be generated from both humic and sapropelic organic matter at different stages and that natural gases could be organic and inorganic …  相似文献   
12.
珠江口盆地珠三坳陷层序地层样式分析   总被引:10,自引:0,他引:10  
珠江口盆地珠三坳陷是一个典型的箕状断陷盆地,其层序地层格架受到主干断裂特别是珠三南断裂的强烈控制。由于珠三南断裂活动的差异性,盆地东部、中部和西部表现为不同的格架样式。并据此划分出坳陷内的3种典型层序样式,分别是缓坡型、断控陡坡型和断阶型层序样式。文昌A凹陷与阳江低凸起过渡的斜坡区和文昌B凹陷与琼海低凸起过渡区为具有坡折的缓坡背景,发育缓坡坡折型层序样式,发育斜坡扇、盆底扇、低位楔。珠三南断裂等主干断裂下降盘发育断控陡坡带层序样式,在珠三南断裂中部地区,发育断阶型层序样式。  相似文献   
13.
目前水平井射孔完井已在国内外各油田取得了广泛的应用,射孔参数的优化是水平井经济、高效生产运行的关键。在建立了基于正交试验的水平井射孔参数优化设计模型的基础上,研究并筛选了影响水平井射孔完井产能的9个主要因素,分析了各因素对水平井产能影响的权重,优化了射孔完井参数方案,为水平井射孔参数优化提供了新的方法和技术支持。  相似文献   
14.
The Qiongdongnan Basin is a strongly overpressured basin with the maximum pressure coefficient over 2.2. Two types of vertical overpressure configuration can be identified by electronic logs and mud pressure, based on the calibration with the test pressure. The first is a double overpressure configuration, in which the middle low overpressure zone divides the entire overpressure zone into two zones. The double overpressure configuration lies primarily in the western part of the basin. The second is a single overpressure configuration, in which overpressure increases with depth. The single overpressure configuration lies primarily in the eastern part of the basin. Distribution maps of the overpressure top and overpressure horizons show three important characteristics: (1) The distribution of the pressure coefficient is not uniform. There are many low overpressure zones against a background of high overpressure. (2) The pressure coefficient in the western area is greater than in the eastern area. The maximum pressure coefficient in the western area is greater than 2.2. (3) There is a low overpressure interval between the high overpressure zones in the western area. Based on the overpressure distribution, some important implications for hydrocarbon exploration can be drawn. In the Qiongdongnan Basin, it has been shown that normal pressure zones are favorable for hydrocarbon accumulation, and strongly overpressured zones (pressure coefficient greater than 1.8) are unfavorable for hydrocarbon accumulation. Accordingly, the NW low overpressure belt around wells R, Q and S should be beneficial for hydrocarbon accumulations, and should be considered as the next exploration play in the Qiongdongnan Basin. Theoretical hydrofracture calculation and interpretation of the sand injectites indicate the presence of widespread hydrofractures in the basin. Comparison between the sealing capacities of the double overpressure and single overpressure configurations shows that the former is superior for hydrocarbon accumulation and preservation. Because of the strong sealing capacity provided by the displacement pressure and pore pressure difference between the seal rock and reservoir in the double overpressure configuration zone, hydrocarbons barely penetrate the seal rock in the middle low overpressure zone. Therefore, the exploration interval should be within and below the middle low overpressure zone in the western basin.  相似文献   
15.
16.
南海北部琼东南盆地陵水段峡谷沉积建造及勘探意义   总被引:7,自引:6,他引:1  
琼东南盆地中央峡谷为一大型轴向峡谷体系,具有明显的"分段性"特征,不同区段沉积充填和内部结构均存在明显的差异,其中陵水段位于峡谷西段,具有非常好的储层物性特征,是深水区峡谷勘探的重点区域。为了进一步精细刻画陵水段峡谷内部水道复合体的沉积充填及沉积微相展布特征,本文借助新增加的三维地震资料和新钻井资料,通过峡谷三级层序界面的识别,将峡谷充填划分为3个三级层序SQ1、SQ2和SQ3,并通过古生物有孔虫化石带、钙质超微化石带及井-震结合确定了峡谷底界为中中新世晚期S40界面,陵水段峡谷自西向东依次识别出6种主要的内部充填结构,且将SQ3层序细分为5个次级层序(SSQ1~SSQ5);结合属性特征,精细刻画了陵水段峡谷内沉积微相平面展布及空间演化特征,并指出点砂坝在SSQ1层序最发育,且规模较大,横向上连片分布,将是下步勘探的有利储集体。  相似文献   
17.
A recent island survey reveals that the Xuande Atoll and the Yongle Atoll in the Xisha Islands can be classified into one of two systems: the depleted atoll system and growth atoll system; the survey also indicates that the decreased area of several shoals is an unbearable burden for the Xisha Islands, of which the largest island area is 2.13 km2 and the minimum elevation is 1.4 m. According to a survey on the ecological characteristics of Halimeda in the Laolongtou breaker zone of Shidao Island in the Xisha Islands, the green and white living Halimeda are collected,the isotopic ages of 14 C contained in the Halimeda are shown to be 27 years and 55 years, respectively, and carbonate mainly occurs in five types, i.e., luster, segment, sand, sand grain, and marl in the formation. The Halimeda segments mainly provide the carbonate sediments of long-term biogenic deposits in the reef environment and the annual productivity per area is 60–100 g/m2; the characteristics of the microstructure of the Halimeda are analyzed, the aragonite raphide carbonate is deposited and enriched in the cortexes, medullas and cysts, and the Halimeda generally contain major elements such as C, O, Ca, Cl, Mg, K, Na, S and Al, and are rich in trace elements such as tellurium(Te), rhodium(Rh) and strontium. It is believed that the Halimeda grow slowly,including the biotic community of reef corals in the reef areas, thus they possess an environmental remediation capacity, but it takes much time to remedy the environment, and it is necessary to make the law to protect the diversity and vulnerability of the Xisha marine ecology, the ecology of the reef community and the island environment in a scientific way. As indicated in the survey, under the background of global warming and sea-level rise, the discovery of large amounts of Halimeda in the Laolongtou sea area is significant for the natural increase of the depleted atoll system of the Xuande Atoll, while the Halimeda segments represent the primary form of the fossil Halimeda, of which the species can be identified and preserved in great numbers under geological conditions. The Miocene was discovered in large amounts in the Xichen-1 well, therefore the study on the characteristics and mechanism of Halimeda carbonate sediments plays a pivotal role in the formation and construction of organic reefs in the South China Sea as well as oil and gas exploration.  相似文献   
18.
琼东南盆地深水区中央峡谷黄流组物源特征   总被引:3,自引:2,他引:1  
物源分析作为岩相-古地理研究的前提和基础,物源体系决定了砂体的展布和储集性能。为明确中央峡谷体系黄流组储集体展布规律及下一步勘探方向,本文应用中央峡谷最新钻井资料,采用重矿物组合、锆石U-Pb测年等分析方法,结合地震反射特征,对中央峡谷黄流组物源体系特征进行分析。地震反射特征表明来自海南隆起和昆嵩隆起物源的三角洲体系,通过二次搬运沉积了陆架斜坡区和盆底的低位海底扇,为中央峡谷的沉积充填提供了充足的粗碎屑沉积物;新钻井黄流组样品中重矿物组合以白钛矿、石榴石、磁铁矿含量较高为主要特征,与莺歌海盆地受蓝江物源影响和琼东南盆地受丽水-秋滨河物源影响的地层重矿物组合相似;锆石U-Pb测年分析表明,中央峡谷黄流组地层中样品年龄图谱具有30~2 000Ma变化范围,与莺歌海盆地受昆嵩隆起物源影响的钻井以及越南现代河流采集的沙样具有非常一致的年龄段和丰度。综上所述,中央峡谷受多物源的影响,越南昆嵩隆起为主的琼东南盆地西部物源体系,是琼东南盆地乐东凹陷晚中新世深水扇以及中央峡谷粗碎屑物质的主要沉积物供给来源区。  相似文献   
19.
深水沉积理论的深入研究发现,传统的浊流沉积理论如鲍玛序列、浊积扇、浊积岩相等可能需要重新解释,对浊流理论的质疑推动着深水沉积理论的发展。通过对浊流沉积研究历史及当前研究现状的梳理,探讨了浊流及相关重力流沉积理论的新观点。  相似文献   
20.
The Dongfang1-1 gas field (DF1-1) in the Yinggehai Basin is currently the largest offshore self-developed gas field in China and is rich in oil and gas resources. The second member of the Pliocene Yinggehai Formation (YGHF) is the main gas-producing formation and is composed of various sedimentary types; however, a clear understanding of the sedimentary types and development patterns is lacking. Here, typical lithofacies, logging facies and seismic facies types and characteristics of the YGHF are identified based on high-precision 3D seismic data combined with drilling, logging, analysis and testing data. Based on 3D seismic interpretation and attribute analysis, the origin of high-amplitude reflections is clarified, and the main types and evolution characteristics of sedimentary facies are identified. Taking gas formation upper II (IIU) as an example, the plane distribution of the delta front and bottom current channel is determined; finally, a comprehensive sedimentary model of the YGHF second member is established. This second member is a shallowly buried “bright spot” gas reservoir with weak compaction. The velocity of sandstone is slightly lower than that of mudstone, and the reflection has medium amplitude when there is no gas. The velocity of sandstone decreases considerably after gas accumulation, resulting in an increase in the wave impedance difference and high-amplitude (bright spot) reflection between sandstone and mudstone; the range of high amplitudes is consistent with that of gas-bearing traps. The distribution of gas reservoirs is obviously controlled by dome-shaped diapir structural traps, and diapir faults are channels through which natural gas from underlying Miocene source rocks can enter traps. The study area is a delta front deposit developed on a shallow sea shelf. The lithologies of the reservoir are mainly composed of very fine sand and coarse silt, and a variety of sedimentary structural types reflect a shallow sea delta environment; upward thickening funnel type, strong toothed bell type and toothed funnel type logging facies are developed. In total, 4 stages of delta front sand bodies (corresponding to progradational reflection seismic facies) derived from the Red River and Blue River in Vietnam have developed in the second member of the YGHF; these sand bodies are dated to 1.5 Ma and correspond to four gas formations. During sedimentation, many bottom current channels (corresponding to channel fill seismic facies) formed, which interacted with the superposed progradational reflections. When the provenance supply was strong in the northwest, the area was dominated by a large set of delta front deposits. In the period of relative sea level rise, surface bottom currents parallel to the coastline were dominant, and undercutting erosion was obvious, forming multistage superimposed erosion troughs. Three large bottom current channels that developed in the late sedimentary period of gas formation IIU are the most typical.  相似文献   
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