Deep-seated gas generation and preservation condition in China

Deep-seated gas is defined in this paper as natural gas generated under the combined action of high temperature, high pressure, and environment media. As to organic matter vertical evolution, deep-seated gas is natural gas, which is generated and deposited under the position of an oil generation window. Deep-seated gas exploration is an important potential field for oil-gas exploration. Also, it is an inexorable trend to the further development of oil and gas provinces. In this paper, the authors will examine and distinguish the concept of deep-seated gas, and discuss the distribution and gas source of deep-seated gas. It is pointed out that kerogen, assemble dissoluble organic matter and disperse dissoluble organic matter all have contributed to deep-seated gas generation, especially disperse dissoluble organic matter in composite and superimposed sedimentary basin. In the end, according to the structural evolution and hydrocarbon source rock depositional distribution, the distribution of deep-seated gas in China is predicted. Translated from Geology in China, 2006, 33(5): 937–943 [译自: 中国地质]     

Application of the time-predictable model in Peninsular India for future seismic hazard assessment

It has been the belief among Earth scientists that the Peninsular Shield is aseismic, as the region attained stability long ago. However, the earthquake at Koyna (10 December 1967), Bhadrachalam (13 April 1969), Broach (23 March 1970), Hyderabad (30 June 1983), Khillari (30 September 1993), Jabalpur (22 May 1997), Gujarat (26 January 2001), and additional ones of smaller magnitudes, altered this concept. This area has experienced many widely distributed shallow earthquakes, some of them having large magnitudes. It is now widely accepted that seismic activity still continues with moderate events. Therefore, a need has arisen to take into consideration recent seismological data to assess the future seismic status of Peninsular India. Earthquake generation model has been studied to develop the statistical relations with surface wave magnitude (M _S ≥ 4.5). Five seismogenic sources showing clustering of earthquakes and including at least three main shocks of magnitude 4.5 ≤ M _S ≤ 6.5 giving two repeat times, have been identified. It is mainly based on the so-called “regional time-predictable model”. For the considered region it is observed that the time interval between two consecutive main shocks depends on the preceding main shock magnitude (M _p ) not on the following main shocks magnitude M _f suggesting the validity of time predictable model in the region.     

华北地区壳内低速层与地壳流变的关系及其对强震孕育的影响

京津唐张地区普遍存在壳内低速层 ,鄂尔多斯块体内部没有发现低速层 ,壳内低速层的这种分布受新生代裂陷伸展的控制。华北地区中地壳下部和下地壳低速层是岩石塑性流变的结果 ,中地壳上部低速层是地壳裂陷伸展时形成的水平拆离带和韧性剪切带 ,岩石各向异性和流体作用可能是引起低速的原因。壳内软弱层 (低速和塑性流变层 )增强了块体层间的解耦作用 ,对地震孕育起着重要作用     

在电宇宙中的二类黑洞的外部度规场和电磁场的严格解

运用Ernst方程内部对称群的Harrison变换 ,得到了E -M场方程的二个新的严格解 ,发现在电宇宙中的R -N度规仍是静态的 ,这与磁宇宙的结果不同。     

基于均生函数的数学预测模型在地震中期预报中的应用

利用均生函数数学建模方法拟合地震的震级或能量序列,进行地震中期趋势预测。由于引入了“双评分准则”,即在拟俣时考虑了数量预报和趋势预报的平衡问题,选取合适的调整系数,从而提高了地震中期趋势预测的准确率。另外采用了分级拟合的思路,利用残差序列逐级提高拟合的精度和速度。利用该方法对中国大陆地区未来１～３年的地震活动趋势进行了预测。     

从波动观点看塔北地区油气藏的形成演化：以英买7油藏为例

本文运用沉积波动过程分析方法,在综合分析野外露头、岩心、录井、测井、地震等资料的基础上,建立了塔北地区不同小区的岩性－时间剖面。研究表明,７４０￣７６０Ｍａ、２００￣２４０Ｍａ、１００￣１１０Ｍａ、６０￣７０Ｍａ、３０Ｍａ是控制塔北地区构造演化的主要周期。早古生代、三叠纪和第三纪以来是３次主要的沉积高峰,志留纪末－晚泥盆世早期为主要肃蚀期,肃蚀量一般〉１０００ｍ,北部〉１５００￣２０００ｍ,海西期     

青藏高原羌塘盆地油气生成特征

本文从沉积、地球化学的角度分析了羌塘盆地的油气生成特征.羌塘盆地的沉积及古地理环境控制了多层系生油岩的形成,但主要为三叠系和侏罗系以海相沉积为主的碳酸盐烃源岩和泥质烃源岩,厚度巨大,有机质丰度高,热演化程度较高,生烃潜力大,构成了羌塘盆地主力烃源岩.综合分析认为盆地南北坳陷连接处的鞍部为含油气远景最有利区.     

Contrasting on Hydrocarbon Generation Model and Characteristics of Pyrolysis of Modern Aquatic Plant (Gloeocapsa) vs Marine Animal (Mantis Shrimp)

INTRODUCTIONGeochemical models of hydrocarbon generation fromorganic matter have become increasingly important inhydrocarbon exploration. They elucidate the relationshipbetween precursor organic materials and the properties ofhydrocarbon products under certain geologic conditions.Previous thermal experiments were successful to a certaindegree in sim ulating the geologic process of hydrocarbonevolution. Khorasani and Michelson (1991) reported thegeneration of liquid hydrocarbon from the co…     

华北东部地区盆地叠合特征与古生界生烃史

华北东部地区下古生界沉积了海相碳酸盐岩潜在的烃源岩,上古生界发育良好的煤系气源岩。由于经历了多期次、不同规模盆地的多种样式的叠合,其间又经历多期次的抬升、剥蚀与改造,因此,不同地区的古生界烃源岩生烃史具有显著的差异。地层对比和上古生界RO特征指示研究区北部的济阳坳陷具有较厚的三叠系原始沉积,三叠纪盆地的叠合对古生界烃源岩生烃史具有重要影响。依据盆地叠合方式、上古生界热演化程度,将上古生界生烃史划分为三叠纪、侏罗纪-白垩纪、早第三纪以来等3个阶段,分别对应生烃史的早期、中期和晚期,早期浅埋、中期抬升、晚期深埋型地区的“二次生烃”潜力大,如济阳坳陷和东濮凹陷。上古生界盆地的均衡面式叠合使下古生界的热演化程度比上古生界至少高0.3%以上,因此,在三叠纪末下古生界基本达到生烃高峰,在一定程度上损耗了其原始有机质并降低其“二次生烃”潜力。     

山西枣圆地区构造演化与煤层气成藏

对山西省枣圆地区的构造演化与煤层气成藏机制进行了研究,结果表明:该区山西组煤层主要经历了两期构造演化:燕山期的近EW向挤压和喜玛拉雅期近EW向水平伸张。构造演化控制了煤层的埋藏史、受热史及成烃史,也直接影响了研究区山西组煤层气的成藏演化。