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91.
92.
四川威远气田烃流体包裹体的研究 总被引：3，自引：0，他引：3
通过烃流体包裹体的类型、均一化温度、气相及液相成分、盐度以及同位素的研究,可以认为威远气田的天然气主要是由白云岩中有机质形成。由于从80～160℃到200～240℃的热解作用,有机物质已演化到过成热阶段。这一过程可由白云岩中存在液态烃及含沥青烃流体包裹体得到证明。威远气田的特征是:震旦系白云岩中天然气的自产自储,以CH_4为主;油田水为古海水,盐度(4.3～17.2)wt%NaCl,pH>8,(CO+CH_4)/CO_2比值指示还原条件。在基底花岗岩石英中发现有气态烃包裹体,其成分及δ~(13)C‰与花岗岩储气层中产出的天然气一致,为部分天然气可能来自深部地壳或地幔提供了新的证据。因而,威远气田天然气的成因主要由有机物质形成,部分甲烷气可能经基底断裂来自地球深处。 相似文献
93.
Data from the super-deep wells(PS10,PS14 and YS1)led to the discovery of widespread met-al-bearing hydrothermal fluids (or hot brines) related to basic magmas in the Lower Tertiary clastic sequence in the Dongpu Depression .In terms of SEM and EDAX analyses, pore-casting thin section examination of sandstone ,the composition and forming temperature of fluid inclusions ,the trace ele-ment composition of mustone and kerogen and organic geochemical analyses, it is demonstrated that the hydrothermal fluids existing in the area studied are ejecting fluids, which have a close bearing on diagenesis and sedimentation, rather than intrusive veins along the tectonic fractures.The main indicators of hydrothermal activity are:(1)abnormal alteration of kerogen;(2) high-temperature altered mineral assemblage;(30abnormal distribution of hydrocarbons;(4) specific assemblages and abnormal contents of heavy metals in mudstone and kerogen;(5) specific composi-tion of complex compounds and assemblages of fluid inclusions in sandstone;(6) periodic basaltic magma activity.Results of geological observations and laboratory simulating experiments demonstrated that the hydrothermal fluids have a close bearing on hydrocarbon generation in the Dongpu Depression. Two aspects of the effect of hydrothermal fluids are noticed:hydrothermal hydrocarbon production and strong metal catalysis in oil and gas generation. 相似文献
94.
An infrared routine has been developed to estimate the aliphatic portion of kerogen carbon in sedimentary rocks. The procedure does not require isolation of the organic matter and is based on a computer-assisted determination of global band areas in the region of the aliphatic carbon-hydrogen stretching vibrations around 2900cm−1. From these integrated absorptions the amount of aliphatic carbon Cal (mg of aliphatic carbon per gram of solvent-extracted rock) is calculated by means of a calibration with model rocks. Carbonate overtones which interfere in the case of limestones are eliminated by comparison to a CaCO3 standard.The method has been applied to rocks containing kerogens of different types and maturities at TOC levels of 0.5 to 12%. The aliphatic carbon concentrations range from 0.5 to 60mg·g−1 and correlate reasonably well with the residual genetic potentials of the rocks as measured by S2 values from Rock-Eval pyrolysis. The ratio S2/Cal is found to decrease with burial depth reflecting a maturity enhanced conversion of aliphatic carbon to fixed aromatic carbon under Rock-Eval conditions. 相似文献
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97.
异常压力与油气分布 总被引：123，自引：2，他引：123
随着油气勘探活动的不断加深，国内外相继发现了许多异常高压油气田。据不完全统计，全世界已发现超压盆地１８０多个，其中１６０多个为富含油气盆地。异常高压油气田约占全球油气田３０％左右，因此，对异常压力的研究，具有举足轻重的意义。本文介绍了异常地层压力的概念、特征及分类；详细论述了异常压力的成因，即烃类生成作用、欠压实作用、液态烃类的裂解作用、粘土矿物的后生成岩作用、构造作用、温度变化等；系统阐述了世界典型含油气盆地的超压形成机制、超压体系中油气初次运移机理以及超压与油气分布关系；并在此基础上，归纳总结出了五种超压油气藏成藏模式，即：（１）位于超压体系中的低渗超压油气藏；（２）位于超压层系中，以礁灰岩（或浊积砂岩）为储层的高压油气藏；（３）位于超压带上倾方向，以退覆三角洲平原和分流河道砂岩为储层的常压或过渡带超压油气藏；（４）位于超压带上、下部的超压油气藏；（５）位于远离超压体系的泄压区常压油气藏，本文对指导、加深新老油气区勘探具有实际应用价值。 相似文献
98.
Barry Jay Katz 《Journal of Paleolimnology》2001,26(2):161-179
Although much of the world's petroleum resource-base is associated with marine systems, regionally lacustrine petroleum systems are important. Individual accumulations may exceed several billion barrels. In each of these cases the oil is derived from a lacustrine source rock and may be produced from either nonmarine or marine reservoir rocks. The purpose of this paper is to describe the factors that control lacustrine source rock development and the nature of lacustrine reservoirs. Lacustrine oils display different physical and chemical characteristics than their marine counterparts. These differences can be related to the nature of their precursor material. Although the nature of the products are different, the geochemical threshold criteria for defining source rocks in both settings are the same because of common expulsion requirements. Commercially significant lacustrine systems require the presence of large, long-lived lakes. Such lake settings are tectonic in origin and restricted to climatic settings where precipitation exceeds evaporation. Within these large lake systems three primary factors determine source rock potential and quality. These factors are primary productivity level, organic preservation potential, and matrix sedimentation rate, which controls the dilution of preserved organic matter. Source rock potential is maximized where both productivity and preservation potential are maximized and sedimentation rate is minimized. To some degree these factors can compensate for each other. Hydrocarbon reservoir potential within lacustrine basins is partially impacted by overall tectonic setting. Within extensional settings, transport distances tend to be limited, with much of the sediment being transported away from the basin. The sediments delivered to the lake are poorly sorted and sedimentologically immature, commonly resulting in poor reservoirs due to both primary properties and their susceptibility to diagenesis. Within rifts better reservoirs tend to develop along platform or flexural margins. Stacking of reservoirs is important in lacustrine systems but baffles and barriers are often present between individual sand units. These barriers form as a result of lake level fluctuations. In compressional settings transport distances tend to be longer, resulting in more mature, better sorted sediments leading to higher quality reservoirs. These reservoirs typically develop in fluvial-deltaic and wave-dominated shoreline settings. Lacustrine carbonate reservoirs are locally important. These carbonates tend to develop during lake level lowstands and are dependent on diagenesis (dissolution and karstification) for porosity and permeability development. Lacustrine reservoirs are often stratigraphically and areally limited and display low individual well production rates. Within pure lacustrine systems exploration opportunities appear to be often restricted by either reservoir presence or quality (i.e., production rates). The best exploration opportunities in lacustrine basins appear to be associated with hybrid systems where a lacustrine source and marine reservoir exist. 相似文献
99.
本文在对冷湖七号油气成藏条件综合分析的基础上,依据构造发育史与烃源岩生、排烃史,结合流体包裹体均一温度,分析了冷湖七号构造油气藏形成期次和过程,总结了东、西2个构造高点的油气成藏模式。研究结果表明:①冷七1井N12层包裹体主要为含烃盐水包裹体和气态烃有机包裹体,其均一温度明显分为60~70℃和110~130℃两个峰值区,对应地质时间分别为N21—N22时期和N2末—现今。结合源岩生、排烃史和构造演化史分析表明N12—N22时期为冷湖七号油气成藏的主要时期;②冷湖七号东高点N21气藏形成机理与模式为:断控同生隆起—单源供烃—不整合、断裂输导—浮力驱动—次生型断裂遮挡油气成藏模式;西高点E3油藏形成机理与模式为:同生隆起—双源供烃—不整合、断裂输导—浮力驱动—残留型原生油藏成藏模式。 相似文献
100.