Organic Petrological Studies on Immature Source Rocks

Organic petrology is a marginal science that is quite practicable. At present, it has developed into a routine research tool that is widely applied in petroleum exploration and assessment. Based on several years‘ research of the authors, this paper presents the advances in organic petrological studies on immature source rocks, including the classification and characteristics of macerals, the composition of macerals and types of organic matter, the abundance and evolution of organic matter, oil-prone macerals, hydrocarbon generation and expulsion. All these results show that organic petrology is of considerable value pertaining to its application in the assessment of immature oil and gas. The immature source rocks consist of various macerals with obvious heterogeneity, contain different hydrocarbon-generating macerals with different oil thresholds and oil peaks, and show a two-staged evolutionary pattern of organic matter.     

Migration Fractionation of Neutral Nitrogen Compounds of Crude Oils from Tabei Oilfield in the Tarim Basin, China

The absolute amounts and relative distributions of neutral nitrogen compounds in the Tabei oilfield (e. G. Blocks Ln1-Ln1 1) showed remarkable migration fractionation in the vertical direction. From Ordovician reservoirs (O) to oil legs TⅢ and T Ⅰ of Triassic reservoirs in blocks LN1-LN11, the concentrations of [a] [c] decreased from 1. 59μg/g, 0.49μg/g to 0.17 μg/g (oil). The ratios of various alkylcarbazole isomers, such as 1,8-dimethylcarbazole/nitrogenpartially shielded isomers and 1,8-dimethylcarbazole/nitrogen-exposed isomers, were adopted as the indicators of petroleum migration. The ratios increased from 0.13, 0.20 to 0.67 and from going from the south to the north of the Tabei oilfield, the absolute concentrations of neutral nitrogen compounds decreased drastically, and the nitrogen-shielded isomers were enriched relative to nitrogen-exposed isomers and nitrogen-partially shielded isomers. Crude oils in the Tabei oilfield migrated laterally from the Jilake structure to the Sangtamu fault uplift and Lunnan fault uplift, and crude oils in the same fault uplift migrated and remigrated vertically from Ordovician reservoirs, to oil legs TⅢ to TⅠ of Triassic reservoirs.     

Composition of Kerogen in Kupferschiefer from Southwest Poland

Thirty-seven Kupferschiefer samples from southwestern Poland were analyzed by microscopy, Rock-Eval approach and instrumental neutron activation analysis to understand the geochemical and morphological characteristics of kerogen present in the samples. The analytical results indicate that there are two different types of kerogens. One type was only subjected to thermal alteration processes, and the other was further oxidized after deposition of the sediment.In the oxidized samples migrabitumen was transformed into pyrobitumen. Rock-Eval analyses show a significant decrease in HI values in the oxidized samples and an increase in OI values in relation to the samples that were not influenced by oxidation. Variations in S2 versus Corg contents indicate a change in kerogen from Type II to Type III with progressing oxidation. The presence of pyrobitumen and the depletion of hydrogen in the altered kerogen allow one to conclude that the kerogen was used as hydrogen donor for thermochemical sulfate reduction(TSR).     

Isotopic Characteristics and Key Factors Favoring the Formation of Fuwan Super-large Silver Deposit in Guangdong Province

Rb-Sr isochron age of fluid inclusions in quartz from the Fuwan super-large silver deposit is 68 - 6 Ma, the silver deposit is characterized by high μ values (10.67 - 10.95 ), which are much higher than those of the ore-hosted Paleozoic strata and are close to those of ores hosted in the Proterozoic metamorphic basement in western Guangdong Province. Based on the Pb isotopic characteristics, coupled with much high background silver contents (200-1000ng/g) in the Proterozoic basement and relatively low silver contents in the Paleozoic strata in the region of the Sanshui Basin, it is concluded that the ore-forming material of the super-large silver deposit came mainly from the old basement. The super-large silver deposit related genetically to the intense volcanic activities during the Upper Cretaceous to Eogene. The formation of the Fuwan super-large silver deposit is controlled by the following favorable geological conditions : ( 1 ) The intersection of deep faults and contemporaneous faults at the margin of the Sanshui Basin led to the formation of an excellent structure as passageway for ore fluids; (2) The special ore-hosted rock association forms a ore gathering-trap structure that favors the precipitation of ore; (3) The silver-rich old basement, multi-stage mineralization and multi-episode volcanic activities which constitute a geothermal convection system.     

Biomarkers in the Molar Tooth （MT）-Bearing Limestones in the Jilin-Liaoning Area of China

The origin of Molar Tooth (MT) carbonates has been argued for more than 100 years, which are a kind of Proterozoic carbonates especially composed of microsparite with ptygmatically folded and sheet-like structures. Biomarkers detected in the microcalcsparite from the Wanlong and Xingmincun formations in the Jilin-Liaoning area showed there are abundant normal alkanes, isoprenoids, hopanes, steranes, alkylmethylcyclohexanes, and alkyleyclohexanes, indicating a diversity of biological source: long-chain isoprenoids, the major components of chlorophyll, such as C19, C20, a kind of major biomarkers synthesized early by isoprenoid monomers; hopanes a type of characteristic biomarkers from prokaryote, such as archaebacteria and cyanobacteria; sterane a biomarker for eukaryote; and two kinds of alkanes with C17, C18 as the main peaks representing aquatic bacteria and with C23, C24 as the main peaks representing fungi, respectively. Biomarker analysis showed that MT is the result of bacterial and algal activities, which is a kind of organisms between aerobic and anaerobic bacteria, reproducing well in normal or slightly saline sea water under weak oxidation-reduction conditions, resulting in rapid deposition of calcite as microsparite clue to some mechanisms.     

超深防渗帷幕性质研究及设计优化

防渗帷幕在很多国家得到较广泛的应用 ,但深度超过 35m较少。防渗帷幕其施工目标参数控制难度大 ,而且深度增加导致难度更大。因此施工目标参数对施工影响起关键决定作用。究竟应如何确定合理的目标参数 ,即保证防渗帷幕的工程作用 ,又不会增加施工难度和工程造价 ?通过土力学基本理论分析 ,并针对各影响因素进行多工况比较计算 ,然后对比现行相关规程规范 ,提出保证降水帷幕发挥作用的施工参数     

钱家营矿首采区断层在剖面上的延伸规律

通 过对 开滦钱 家营 矿首采 区地 质资料 的综 合分析 ,得 出了 该 矿首 采区 断 层在 剖面 上 的变 化特 征 及规 律,并运用这些 规律 ,对未 采区进 行预 测、预报 ,正确 指导了 采掘 工程的 顺利 进行。     

露天矿非工作帮移动监测及滑坡规律性讨论

根 据 某露 天 煤 矿 非工 作 帮 移 动监 测 的 多 年资 料 ,总 结 出 露 天矿 非 工 作 帮的 监 测 方 法,并 初 步探 讨 了 露 天 矿非 工作 帮 移动 滑坡 的 规律 性。     

颗粒分析用量筒的规格标准和计量标定

文章讨论了国内外用于密度计法颗粒分析用量筒的计量标准的规定，提出了相应的建议和标定方法。     

水域静力触探设备的研制和应用

为详细了解崇明越江通道南港隧道段地层情况 ,设计要求提供长江水域静探资料。简介了我院水域静力触探设备的研制和应用情况