Process and mechanism for oil and gas accumulation,adjustment and reconstruction in Puguang Gas Field,Northeast Sichuan Basin,China

With the discoveries of a series of large gas fields in the northeast of Sichuan Basin, such as Puguang and Longgang gas fields, the formation mechanism of the gas reservoir containing high H2S in the ancient marine carbonate formation in superposition-basin becomes a hot topic in the field of petroleum geology. Based on the structure inversion, numerical simulation, and geochemical research, we show at least two intervals of fluid transfer in Puguang paleo-oil reservoir, one in the forepart of late Indo-Ch...     

Distribution of the indigenous microorganisms and mechanisms of their orientational activation in Daqing Oilfield

The distribution of indigenous microorganisms was surveyed in Block 1 of Daqing Oilfield. Based on this survey, the indigenous microorganisms in the formation water were activated with different activator systems at the simulated stratum ecological environment. The changes of the number of bacteria of various physiological groups were determined during the process of activation. Also changes of pH value and composition of gas productions were analyzed at the end of culturing. The results showed that the selected block formation water contained a great number of saprophytic bacteria, hydrocarbon-oxidizing bacteria, fermentative bacteria, methane-producing bacteria and sulfate-reducing bacteria. Under the conditions that the growth of sulfate-reducing bacteria was controlled the block had the potential to enhance oil recovery by activating beneficial bacteria. The growth of sulfate-reducing bacteria can be inhibited through the activation of nitrate-reducing bacteria. The number of nitrate-reducing bacteria reached 10⁶–10⁷ cells/mL, but sulfate-reducing bacteria reached only 0–45 cells/mL in A system. Methane-producing bacteria can be activated by C, D activators. The relative content of biological methane in the light hydrocarbon gas reached 80% in C, D systems. B activator was conducive to the propagation of acid-producing bacteria, so that the pH value of the culture medium decreased from 7.5 to around 5.0. Hydrocarbon-oxidizing bacteria can be activated by various activator systems. There was low molecular light hydrocarbon in gas production according to the analysis of gas chromatograph. According to the content of methane and the number of methane-producing bacteria, methane only can be generated through activating methane-producing bacteria. By choosing different activator systems, various populations of indigenous microorganisms can be activated accordingly.     

Zircon U-Pb SHRIMP ages of the Taiping (calc-alkaline)-Huangshan (alkaline) composite intrusion: Constraints on Mesozoic lithospheric thinning of the southeastern Yangtze Craton,China

The Taiping-Huangshan composite intrusion is a unique complex with characteristics changing from calc-alkaline (Taiping intrusion) to alkaline (Huangshan intrusion). Huangshan intrusion samples show a spectacular tetrad effect in their REE distribution patterns as well as non-CHARAC (charge-and-radius-controlled) trace element behavior, indicating a highly evolved late-stage magma component. This composite intrusion provides a rare opportunity to investigate the variance of tectonic setting and lithospheric thinning of the southeastern Yangtze Craton in late Mesozoic era. Zircon SHRIMP U-Pb analyses yield an emplacement age of 140.6±1.2 Ma for the Taiping intrusion, and ages of 127.7±1.3, 125.7±1.4, 125.1±1.5, and 125.2±5.5 Ma for four samples from the Huangshan intrusion respectively. The ages for four different phases of the Huangshan intrusion agree within their small analytical errors, indicating that the emplacement was in a short time. The Taiping and Huangshan intrusions are intimately associated, but there is about 15 Ma interval between their intrusion, and the magma characters change from calc-alkaline to alkaline without transition. This probably corresponds to lithospheric thinning of the southeastern Yangtze Craton. This event possibly happened from about 141 Ma (the emplacement age of the Taiping intrusion), to 128 Ma (start of emplacement of the Huangshan intrusion). The thinning mechanism is dominantly delamination.     

TOMRADE和MODTRAN 3.7模式研究紫外后向散射探测臭氧总量问题的比较

本文利用MODTRAN 3.7和TOMRADE模式分别计算了308.0 nm、312.5 nm、317.5 nm、322.3 nm、331.2 nm、360.0 nm六个紫外波段的后向散射强度并进行了比较,且利用两个模式计算得到的插值表,对EPTOMS实测资料分别进行反演,得到结论如下：1）两模式算得的后向散射强度随着太阳天顶角、卫星天顶角、地表反照率的变化特性基本一致,均能较好的反映紫外后向散射的辐射特性;2）总体而言,两模式计算的后向散射强度值相对偏差在－6％～18％之间;3）分别把MODTRAN 3.7和TOMRADE模式计算的插值表用于2003年7月30日中纬度地区EPTOMS实测资料的反演,得到的臭氧总量相对偏差在－3％～5％之间.本文对紫外波段大气辐射传输模式的研究和紫外后向散射探测臭氧总量的反演误差研究有着重要意义.     

参数化地震子波估计模型定阶方法研究综述

参数化模型地震子波提取中模型阶数的确定对子波提取的精度至关重要,笔者针对因果地震子波MA、ARMA模型,总结了目前比较成熟的四类定阶方法：相关分析法、信息量准则法、线性代数法及基于优化算法的模型定阶方法,分析比较发现这些算法都存在不同程度的缺陷,只能在各自的适用范围内得到较好的定阶结果,针对算法在子波建模应用中的不足提出了改进建议;同时分析比较了基于高阶累积量的非因果系统模型定阶的各种方法,并对非因果地震子波模型定阶进行了展望.     

中国4个国家级野外站大气CH4本底浓度变化特征

CH4是仅次于CO2的重要温室气体。2006年9月至2008年8月期间,按全球大气本底观测要求,在青海瓦里关、北京上甸子、浙江临安和黑龙江龙凤山4个国家级野外站开展每周一次空气样品flask瓶采样分析,获得了该地区为期2 a的大气CH4本底浓度资料。结果表明,2 a间瓦里关、上甸子、临安和龙凤山4站CH4浓度年均增幅分别为9.1×10-9、3.8×10-9、21.8×10-9和8.2×10-9;瓦里关站大气CH4浓度增长趋势与全球平均状况较为接近,能较好地反映北半球中高纬度内陆地区大气本底特征;但上甸子站年均本底值相对较低且季振幅偏小,而龙凤山和临安站季节变化规律相似,表现为CH4浓度冬季高而夏季偏低且季振幅较大。     

自然与人文交互作用下的干旱区典型绿洲耕地动态变化驱动力分析——以新疆于田绿洲为例

 绿洲是干旱区独特的自然景观,是人们生产生活的载体。如何在保持经济发展、提高人民生活水平的基础上保护有限的耕地资源,是关系到干旱区绿洲和谐以及可持续发展的重要问题。选取干旱区典型绿洲——于田县1949\_2004年的自然与人文统计资料,首先分析了五十余年来该县耕地变化的情况。然后从自然与人文两个角度对影响耕地面积变化的因子进行分析,结果表明,自然因素往往构成一定区域绿洲发展的基本限制,人为因素在短时期内,对耕地的变化起着决定性作用,这种作用如果顺应自然因素的限制,则对绿洲发展有利,绿洲稳定性增强;反之,绿洲稳定性减弱,由于新疆绿洲外围多为戈壁及沙漠,因此,对绿洲的利用要遵循自然规律,以保护绿洲为前提,合理利用水等自然资源,否则绿洲的面积随时都有可能缩小。     

胶州湾水母类生态研究Ⅱ.优势种丰度的时空分布

根据2003年5月-2004年9月胶州湾浮游生物浅水Ⅰ型网中水母的调查资料,分析了胶州湾水母类优势种丰度的季节变化及水平分布.结果表明,对于优势度最大的优势种,半球美螅水母一年中有6月和9（8）月两个丰度高峰,2003年6月丰度最高,达29.5ind/m^3,占当月水母总丰度的47.2 %;薮枝螅水母一年中有9（8）月份和4月份两个丰度高峰,2003年9月份的丰度最高,达12.9ind/m3,占当月水母总丰度的17.4%,4月份该种的丰度占水母总丰度的93.1%;五角水母在9月份丰度高达28.8ind/m^3,占当月水母总丰度的38.7%;八斑芮氏水母2、3月份的丰度均很高,分别为64.7ind/m3、118.0ind/m3,分别占水母总平均丰度的99.5%和98.0 %.对于优势度较小的优势种：四枝管水母、日本真瘤水母、四手触丝水母,真拟杯水母和锡兰和平水母,由于在个别月份占优势,其丰度高低随种类的不同及所在月份的不同而不同.就丰度水平分布来讲,不同优势种类的分布不同时间有所不同,但其丰度分布大都倾向于以湾顶区、湾西部、湾东北部、东部港口沿岸、黄岛沿岸为密集中心.     

岩溶地区枯水资源承载力概念与讨论——以贵阳市为例

明确提出岩溶地区枯水资源承载力的概念和基于岩溶地区枯水资源承载力的计算模型及其分类系统,并以贵阳市为例进行实例研究。结果表明: ( 1)用水类型由温饱型过渡到初步富裕型,枯水资源对各种用水对象承载力总体呈下降的趋势; ( 2)目前贵阳市应采取“总体小康型”的用水类型,以能更好地发展贵阳市的经济; ( 3)从整个区域上看,修文县是最大的缺载区域,具有很大的枯水资源经济发展空间,人水关系呈可持续的发展状态;云岩区是最大的超载区域,枯水资源已经严重地制约着该区经济发展,人水关系呈不可持续发展状态。      

白云岩体表生成岩裸露期古风化壳岩溶的规模

白云岩体表生成岩裸露期古风化壳岩溶对白云岩体古岩溶储渗体的形成至关重要。表生成岩裸露期古风化壳岩溶可形成地表残积层和表层之下大小不等的溶蚀空间。地表残积层与上覆盖层间可成为油气的储渗空间和通道,表层之下大小不等的溶蚀空间则可被塌积岩、冲积岩、填积岩和淀积岩充填,但其内常可保存部分孔隙,并为后来的埋藏溶解提供流体扩溶的初始空间和流体流动的通道。野外露头和井下岩心中的大量现象和事实说明,白云岩体表生成岩裸露期古风化壳的规模远小于石灰岩体。最主要原因是白云岩(石)可溶性远较石灰岩(方解石)小,同样组构的白云岩的物理力学强度亦较石灰岩小。白云岩体本身的岩性和组构、层理类型、泥质含量、构造裂隙的发育程度等都会影响裸露期古风化壳的规模。