现代油藏描述关键技术

现代油藏描述提倡勘探开发一体化,真正实现测井与地震信息匹配,实现静态信息与动态信息结合,最终由定性走向定量。重点阐述了现代油藏描述中,通过集成高分辨率的岩石物理数据、中分辨率的测井数据及低分辨率的地震数据,采用储层自动划分对比及储层结构分析技术、沉积微相自动识别技术、波形差异分析法预测高产气区技术对不同勘探开发阶段、不...     

An extensive erosion surface of a strongly deformed limestone bed in the Gushan and Chaomidian formations (late Middle Cambrian to Furongian), Shandong Province,China: Sequence–stratigraphic implications

In order to understand sequence development and sea-level fluctuations during the late Middle Cambrian to early Furongian on the North China epeiric platform, the present study focuses on a unique, subtle erosion surface of an extensive (approx. 100 km), strongly deformed limestone bed in the uppermost part of the Gushan Formation, Shandong Province, China. The Gushan Formation and the overlying Chaomidian Formation consist mainly of shales and a variety of carbonates that were deposited in subtidal environments (e.g., deep subtidal, shallow subtidal, shoreface/shoal, subtidal microbial flat, and restricted platform interior). Three third-order depositional sequences (S1–3) are identified, each of which comprises a thin transgressive systems tract (TST) and a relatively thick highstand systems tract (HST). Each sequence is bounded by a drowning unconformity (SB1), a subaerial unconformity (SB2), or a surface of submarine erosion (SB3). The upper sequence boundary (SB2) of sequence 1 (S1) is represented by a subtle erosion surface of an extensive, deformed limestone bed with a wide variety of soft-sediment deformation structures (e.g., lime mudstone breccias, chaotic wacke-packstone laminae and fragments, homogenized oolites, and clastic dykes), and is overlain by small sporadic microbial buildups and an extensive bioclastic grainstone bed. The deformed limestone was formed during early diagenesis by differential deformation processes (brecciation, liquefaction/fluidization, and injection) which were most likely induced by pore-water overpressure during the period of rapid sea-level fall. Despite the lack of subaerial exposure features (e.g., paleokarst, paleosol, etc.), the characteristics of the erosion surface (cutting well-lithified sediment below), the missing of a significant geological record (the Prochuangia biozone), and the worldwide correlatable positive carbon isotope excursion collectively indicate that the erosion surface developed under conditions of subaerial exposure after contemporaneous marine cementation of the deformed sediment. The missing of the Prochuangia biozone is most likely due to non-deposition at a subaerial hiatal surface. The erosion surface was submerged as a result of subsequent rise in sea level, where sporadic microbial buildups formed under suitable conditions. Freshly deposited, winnowed, shell-dominated transgressive lag deposits (containing Chuangia trilobite fragments, brachiopod shells, and abundant glauconite grains) formed with continued rise in sea level, which became, in turn, overlain by shale-dominated facies. The unique combination of the subtle erosion surface (sensu stricto a subaerial unconformity) and the underlying deformed limestone bed provides an important criterion for recognizing the subtle changes in relative sea level on shallow epeiric platforms.     

Major element chemistry of the Huai River basin, China

The chemistry of major ions (Ca, Mg, Na, K, HCO₃, SO₄, Cl and Si) in the water of the Huai River basin was studied, based on samples from 52 sites from nine different water bodies in July 2008. Ions and total dissolved solids (TDS) displayed clear spatial patterns with lower concentrations in the south and higher in the north of the basin; the same conditions were also found in the East Line of South-North Water Transfer Project (SNWTP) in this region. The Huai River main channel and Hongze Lake have moderate ion concentrations relative to the whole basin. TDS concentrations versus the weight ratios of Na/(Na + Ca) and ternary ions demonstrate that the southern rivers (Shi R. and Pi R.) are mainly controlled by the weathering of carbonates, whereas the northern water systems (Guo R., Shaying R., Nansi Lake and its tributaries) are dominated by the weathering of evaporites. The Huai River main channel, Hongze Lake and the East Line of SNWTP are synergistically influenced by weathering of evaporites and carbonates, yet Hongze Lake and the East Line of SNWTP are mainly controlled by evaporation and crystallization processes. This study also confirmed that the Huai River is the geographic division between southern and northern China. Most rivers of this basin have very high ionic composition relative to the global median and other world rivers. The spatial patterns and ionic composition also suggest that intensive anthropogenic activities in northern areas of this basin are well characterized. A comparison with WHO and Chinese standards for drinking water indicates that the northern water systems of this basin are not suitable for use as drinking water sources, and pollution control should be improved and enhanced in northern areas of the basin.     

海塔盆地优质储层发育特征及控制因素分析

凝灰质砂岩是海塔盆地主要油气储集岩层,凝灰质含量随地层变老而增多,储层物性非均质性强,大量薄片等储层微观分析结果表明,凝灰质砂岩成分和结构成熟度较低,储层储集空间主要为溶蚀成因的次生孔隙,且次生孔隙比例随地层变老而增加.本文提出孔隙成因法,并根据该方法确定凝灰质砂岩优质储层物性下限的孔隙度为10％,渗透率为0.1×10...     

古火灾历史重建的研究进展

火是地球系统的重要组成部分,与气候、植被、生物地球化学循环和人类活动密切相关。火对全球气候和生态系统的影响已成为目前全球变化研究的一个热点。火灾发生后会在周围的环境中留下许多燃烧产物,如黑碳、木炭屑、多环芳烃、左旋葡萄糖等,它们广泛存在于海洋、湖泊、河流、土壤和陆地风成沉积物中;还会留下一些火灾痕迹,如树木火疤、土壤磁...     

泥石流流域岩性的坚固系数与暴发频率的关系

坚硬岩性地区的泥石流暴发频率较低在定性上基本可以概括岩性与泥石流暴发频率的关系,但目前还没有定量地描述岩性与泥石流暴发频率的关系。以四川省17个泥石流流域作为研究对象,通过现场调查研究泥石流形成区和堆积区粗化层颗粒的岩性、硬度以及泥石流的暴发频率,得出：①泥石流堆积区岩性组成特征基本可以代表形成区的岩性组成特征;②用地...     

Characterization of EmpA protease in Vibrio anguillarum M3

EmpA is an extracellular metalloprotease secreted by Vibrio anguillarum.For better understanding its role in the patho-genicity of V.anguillarum strain M3,empA insertion mutant was constructed.In the mutant it decreased in extracellular proteolytic activity,swarming motility,hemolytic activity and virulence on turbot(Scophthalmus maximus).Significant decline(by 5-fold)of extracellular proteolytic activity and similar growth curve between mutant and wild type strains indicated that EmpA was the major extracellular protease of M3.LD50 of mutant increased by 38-fold compared with wild type.No pro-EmpA was detected in the su-pernatant of culture,indicating that EmpA autolyzed to mature protein after 24 h.Secretion of EmpA in M3 was similar to that in NB10 strain.Attenuated virulence of mutant was similar to that of M93Sm strain.It was demonstrated that specific operation of EmpA was different from that in previous studies and EmpA contributed to the swarming motility and hemolytic activity in V.an-guillarum strain M3.The results provides insight into understanding the function of EmpA and its potential application in vaccine development.     

Diurnal variation in relative photosynthetic performance of marestail (Hippuris vulgaris Linn.) Across a water temperature gradient using PAM fluorometry in Jiuzhaigou National Nature Reserve, Sichuan Province, China

This paper reports the first photosynthetic study of marestail in Jiuzhaigou. In this work, we used PAM fluorometry to examine photosynthetic rates of submerged and emerged marestail in three lakes. Three lakes were studied across a gradient of water temperature, with low water temperature conditions in Grass Lake and Arrow Bamboo Lake, and higher water temperature in Five Colored Lake. In the field, electron transport rates (ETR_max) were measured as rapid light curves (RLCs) by in situ yield measurements. Submerged and emerged marestail showed higher photosynthetic activity in Five Colored Lake compared to the other lakes, a response consistent with the adaptation of marestail in Five Colored Lake to high water temperature. The optimal temperature for photosynthesis of submerged marestail in Jiuzhaigou was about 12 °C. Nonphotochemical quenching (NPQ) of submerged and emerged marestail increased with increasing water temperature. Maximum quantum yield (F _v/F _m) of submerged marestail in Five Colored Lake showed full recovery at 1700 h due to higher NPQ. Further, the chlorophyll a for submerged marestail was the highest in Grass Lake and the lowest in Five Colored Lake. These results indicate that in different lakes the function of these aquatic plants is associated with a diversity of place-dependent environmental conditions, especially water temperature that leads to pronounced differences in the plant’s ecophysiological reactions.