土壤磁化率异常在油气勘查中应用试验研究

应用土壤磁化率结合化探、地震、遥感资料,在内蒙西部荒漠区进行大面积油气勘查的综合研究,结果表明土壤磁化率异常与烃异常有相似的分布趋势,并都受构造控制.根据两个含油气局部构造磁化率异常与磁性矿物含量分析结果,认为磁化率异常的成因是由于含油气构造部位次生磁性物质形成的总体效应所致,因此,应用此方法进行油气勘查,只能作为一种烃蚀变异常的间接指示指标     

壤中游离气方法及其在油气化探中的应用

油气藏中的轻烃气体能够以微弱但可检出的量近似垂直地渗漏到地表土壤中,其中一部分烃类以游离态赋存在土壤或岩石颗粒空隙中.壤中游离气中的烃类能反映深部油气藏烃类的现代补偿性活跃微渗漏,被认为是油气地球化学勘探的最可靠方法之一.壤中游离气采集是获得第四系沉积层中微渗漏烃类地球化学异常的关键技术.自行研制了便携式游离气采集新装...     

新疆伊犁盆地巩留凹陷航空高光谱油气探测

为了进一步了解伊犁盆地巩留凹陷油气勘探潜力,为该地区下一步油气勘查提供依据和新的技术支持,利用航空高光谱SASI数据,采用混合调制匹配滤波(MTMF)方法,在伊犁盆地阿吾拉勒西段山前提取了油气烃信息,主要分布在二叠系晓山萨依组,反映了油页岩层的分布和油气渗漏地段,地表油气渗漏主要受断裂控制,与油气渗漏有关的蚀变主要为粘土化,碳酸盐化次之。在巩留凹陷提取了粘土化和碳酸盐化信息,主要分布在拜石墩与阿克吐别克乡之间,通过干扰因素的排除,在拜石墩南部筛选了四片油气微渗漏区。最后,结合区域地质、物探资料综合分析,认为该地区油气成藏和排烃可能始于燕山早期,在喜山期遭到严重破坏,盆地的不对称压陷,加速了油气的垂直和侧向运移,在盆地内部形成微渗漏,在阿吾拉勒山前沿着断裂逸散至地表形成宏渗漏,巩留凹陷拜石墩南部微渗漏地区对应深部二叠系褶皱带是下一步油气勘查有利目标区。     

植被覆盖地区的高光谱油气勘探技术研究现状

高光谱遥感油气勘探技术利用油气微渗漏所致的地表蚀变矿物异常和地植物异常在光谱上的异常表现提取油气微渗漏信息, 是油气勘探的辅助手段。针对高光谱遥感油气勘探技术在植被覆盖区应用中存在的植被遮挡地表真实情况的问题开展研究, 总结相关领域的国内外研究现状, 指出其存在的问题, 提出了与植被反射率相关的指数作为油气微渗漏的指示标志, 确定了适用于植被覆盖区的高光谱遥感油气微渗漏信息大面积普查的工作流程, 研究成果可为建立更加广泛、适用的高光谱遥感油气勘探模式提供新的参考依据。      

油气化探技术在川西坳陷油气勘探中的应用

自“七五”以来,为配合四川盆地的油气勘探,在川西坳陷开展了一系列油气化探工作,对该区油气的发现起到了重要作用。川西坳陷的地质条件有利于微渗漏烃类以较高浓度赋存于土壤中,从而有利于油气地球化学探测方法的使用。选择有代表性的大型气田——新场气田进行近地表地球化学场特征与石油地质关系解剖,结果表明气田上方近地表地球化学异常是客观存在的,与本区独特的地质环境相对应,并优选出勘探天然气的有效指标组合。这些有效的油气化探方法在川西天然气富集区的预测中同样效果显著,以川西新都-金堂地区油气化探详查为例,许多化探异常经钻探后证实具有工业油气流。上述研究表明,油气化探技术在川西坳陷具有良好的应用前景。     

Integrated geo-microbial and trace metal anomalies for detection of hydrocarbon microseepage in Ahmedabad block of Cambay basin,India

The aim of the present work is to define the geo-microbial signatures along with trace metals, and to investigate whether the geo-microbial anomalies have correlation with trace metal anomalies in Ahmedabad block of Cambay basin. The surface geochemical techniques are based on seepage of light hydrocarbon gases from the oil and gas pools to the shallow surface and can bring up near-surface oxidation reduction zones that favor the development of a diverse array of chemical and mineralogical changes. The paper reports the role of hydrocarbon microseepage in surface alterations of trace metal concentrations and hydrocarbon oxidizing bacteria and its interrelationship. For the purpose a total of 90 soil samples are collected in grid pattern of 2 x 2 km interval. The paper reports the chemical alterations associated with trace metals in soils that are related to hydrocarbon microseepages above some of the major oil and gas fields of this petroliferous region. The concentrations of V (0 to149 ppm), Cr (2 to 192 ppm), Cu (4 to 171 ppm), Se (98 to 440 ppm), Zn (56 to 1215 ppm) are obtained. It is observed that the concentrations of trace elements are tremendously increased when they are compared with their normal concentrations in soils. In this study the hydrocarbon oxidizing bacterial counts ranged between 1.0 x 10³ and 1.59 x 10⁶ cfu/g of soil sample respectively. The attempt has made for the first time, which revealed good correlation as both these anomalies are found as apical in relation. Integrated studies between trace elements and hydrocarbon oxidizing bacterial anomalies showed positive correlation with existing oil and gas wells in the study area.     

基于遥感技术的龙门山前山带烃类微渗漏信息提取

通过对龙门山前山带含油区与非含油区的岩石、土壤、植被等进行测试,认为烃类微渗漏会造成地表热异常、红层褪色、低价铁富集以及粘土矿化等现象,并对研究区的粘土矿物、Fe3+、Fe2+与烃类的波普曲线特征进行了分析对比。以ETM卫星图像为主要信息源,选择了TM2/TM3、TM3/TM4和TM5/TM7进行比值处理,从光谱数据中直接提取出碳酸盐化、粘土矿化、红层褪色等油气蚀变信息,并在对研究区遥感地质解译的基础上,指出烃渗漏信息异常晕主要沿断裂带分布,特别在不同走向断裂的交汇区域分布面积和强度较大,而在已知油气圈闭区域,信息晕主要呈碎片状或斑点状零散分布,且以低值异常为主。根据烃渗漏异常的分布特征,提取出石板滩、中坝、孝泉、聚源、鸭子河以及邛崃等遥感信息异常区块。     

Geochemical exploration for hydrocarbons in the soils of southeast of Krishna-Godavari Basin, Andhra Pradesh

Surface adsorbed gas surveys and geo-microbiological surveys are known techniques of petroleum exploration and aim towards risk reduction in exploration by way of identifying the areas warm with hydrocarbons and to establish intense exploration priorities amongst the identified warm areas. The present investigation aims to explore correlation between the adsorbed gas distribution pattern with the distribution of the counts of methane, ethane, propane and butane microbial oxidizers in the sub soil samples to establish the role of the latter in identifying the upward migration of hydrocarbons especially in the known petroliferous Krishna-Godavari Basin, India. A total of 135 soil samples were collected near oil and gas fields of Tatipaka, Pasarlapudi areas of Krishna Godavari Basin, Andhra Pradesh. The soil samples were collected from a depth of 2?C2.5 m. The samples collected, were analyzed for indicator hydrocarbon oxidizing bacteria, adsorbed light gaseous hydrocarbons and carbon isotopes (??¹³C_methane). The microbial prospecting studies showed the presence of high bacterial population for methane (3.94 × 10⁵ cfu/gm), ethane (3.85 × 10⁵ cfu/gm), propane (4.85 × 10⁵ cfu/gm) and butane oxidizing bacteria (3.63 × 10⁵ cfu/gm) in soil samples indicating microseepage of hydrocarbons. The light gaseous hydrocarbon analysis showed 83 ppb, 92 ppb, 134 ppb, 187 ppb and 316 ppb of C₁, C₂, C₃, nC₄ and nC₅, respectively, and the carbon isotopic composition of ??¹³C₁ of the samples ranged between ? 36.6 ?? to ?22.7?? (Pee Dee Belemnite) values, which presents convincing evidence that the adsorbed soil gases collected from these sediments are of thermogenic origin. Geo-microbial prospecting method and adsorbed soil gas and carbon isotope studies have shown good correlation with existing oil/ gas fields of K.G basin. Microbial surveys indicating microseepage of hydrocarbons can, therefore, independently precede other geochemical and geophysical surveys to delineate areas warm with hydrocarbons and mapped microbiological anomalies may provide focus for locales of hydrocarbon accumulation in the K.G basin.     

基于遥感技术的贵州黔西地区烃类微渗漏信息提取

遥感油气勘探技术具有经济、安全等优势,有很大的应用潜力。针对烃类微渗漏造成地表热异常、红层褪色、低价铁富集以及黏土化等现象,利用TM数据来提取异常信息。文章在研究贵州黔西遥感地质解译的基础上,结合遥感信息探测油气模式,对贵州黔西地区的油气远景区进行了预测。     

Laboratory Simulation of Vertical Hydrocarbon Microseepage

Based on a conceptual model of hydrocarbon microseepage, a macro-sized experimental equipment used the matched mixtures of cement and quartz sand as simulated caprock and its overlying strata is first set up to simulate the processes of hydrocarbon microseepage and its near-surface expressions. The results of the simulation experiments suggest that simulated caprock and its overlying strata have a certain sealed capability; hydrocarbon microseepage is dominated by the pressure of point gas source, and temperature plays only a subordinate role; on the path of hydrocarbon microseepage, the distribution of hydrocarbon concentration is fan-shaped; differential adsorption of alkanes by the simulated caprock and its overlying strata results in the occurrence of a chromatographic effect. Different migrating patterns within simulated caprock are shown by the ratio of i-butane to n-butane. The concentration of hydrocarbon in the surface soil has good correspondence with the pressure of point gas source. These simulation results are significant to further study of the mechanism of anomalies recovered in surface geochemistry exploration.     

青藏高原北羌塘盆地胜利河上侏罗统海相油页岩的发现

随着研究程度的深入,藏北羌塘盆地的油气勘探潜力越来越受到国家的重视。但是由于自然地理条件的制约,羌塘盆地内还有许多有待于发现的问题。2006年在胜利河西、玛尔果茶卡东南上侏罗统索瓦组中发现一套优质的油页岩,该套油页岩有2层,稳定延伸大于2.5km。该套油页岩的发现,不仅为分析北羌塘盆地晚侏罗世盆地演化和古地理格局具有重要意义,而且丰富了羌塘盆地侏罗纪烃源岩的类型,对进一步评价羌塘盆地的油气资源潜力具有重要意义。     

Application of trace metal anomalies for recognition of petroleum prospects in surface sediments of Kutch and Saurashtra Basins, India

Seepage of hydrocarbons, either as macroseepage or microseepage, can set up near-surface oxidation-reduction zones that favour the development of a diverse array of chemical and mineralogic changes. In this study trace metal alterations were mapped that appear to be associated with hydrocarbon microseepages in the oil/gas fields. A total of 210 soil samples were collected from near surface sediments of Kutch and Saurashtra Basins, India. The soil samples were collected from a depth of 2–2.5 m. The paper reports the chemical alterations associated with trace metals in soils that are related to hydrocarbon microseepages above the Kutch and Saurashtra Basins, India. The soil samples for trace metals; Scandium (Sc), Vanadium (V), Chromium (Cr), Cobalt (Co), Nickel (Ni), Copper (Cu), Zinc (Zn), Barium (Ba) and Strontium (Sr) were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The concentrations of the trace elements ranged between for Sc (12.69 to 21.91 ppm), V (109.20 to 436.05 ppm), Cr (87.15 to 481.57 ppm), Co (18.25 to 64.31 ppm), Ni (57.55 to 263.15 ppm), Cu (44.88 to 143.96 ppm), Zn (137.60 to 502.31 ppm), Ba (149.27 to 921.46 ppm) and Sr (143.93 to 425.63 ppm) were obtained. It was observed that trace elements concentrations were tremendously increased when compared with normal concentration in the soils. The adsorbed soil gas analysis showed the presence of high concentrations of ΣC₂₊ (C₂H₆, C₃H₈ and n-C₄H₁₀) ranged between 1 to 121 ppb respectively. Integrated studies of trace elements over adsorbed light gaseous hydrocarbon (ΣC₂₊) anomalies showed good correlation. The carbon isotopic composition of δ¹³C₁ of the samples ranges between — 36.6 ‰ to ?22.7‰ (Pee Dee Belemnite) suggest thermogenic source for hydrocarbon gases. The increase in trace metal concentrations near oil/gas producing areas, suggests that soil chemical change to a reducing environment, presumably due to the influence of hydrocarbon microseepage, which could be applied with other geo-scientific data to identify areas of future hydrocarbon exploration in the frontier areas.     

CONTRAST STUDY OF OIL AND GAS EXPLORATION POTENTIAL FOR QIANGTANG, CHANGDOU AND WEST YUNNAN BASIN DURING JURASSIC

CONTRAST STUDY OF OIL AND GAS EXPLORATION POTENTIAL FOR QIANGTANG, CHANGDOU AND WEST YUNNAN BASIN DURING JURASSIC     

羌塘盆地最大规模沥青脉的发现及其意义

在羌塘盆地已经发现了190余处油气显示。近年笔者在盆地北部晚侏罗世地层中发现了迄今最大规模的沥青脉。研究结果表明，该沥青脉产出于上侏罗统索瓦组地层之中，地层下部系与沥青脉的形成有一定关系的中株罗统夏里组局部含油气显示的盐丘。沥青族组分(％)为：饱和烃5．72、芳烃18．46、沥青质52.37、非烃23．45，说明核沥青脉经过了运移、氮化的过程。同时，沥青脉产出于复背斜范围内，利于油气聚集成藏。这一发现对于羌塘盆地的油气地质的作用具有现实意义。     

松辽盆地西部斜坡带烃类微渗漏遥感信息提取

松辽盆地西部斜坡带位于吉林省西部白城地区。20多口探井证实，油气显示主要集中在东北部套保地区，油气显示最井是洮13井，其次为洮5井和洮5井和洮6井。烃类微渗漏遥感直接探测技术是一种直接找油方法，是90年代以来发展的一种新方法，目前已被国内外石油勘探部门广泛应用。通过对液态、气态、固态石油物质光谱特性的分析，采用比值处理，加TM4／TM7、TM4／TM5、TM4／TM3来增强微弱的烃类微渗漏异常；并将波段的比值或原波段进行彩色合成提取了研究区烃类微渗漏异常，其结果与已知钻孔的含油气情况一一对应，同时在研究区西部角发现一些新的油气渗漏异常区，可作为研究区油气勘探进一步工作的优先靶区，对研究区的油气勘探有较好的指导意义。     

油气田微磁异常成因及性质研究的近期进展

微磁测量是80年代出现的一种成功的非常规油气勘探方法,它所检测的是与油气渗漏相关的次生磁性矿化作用。近期的大量研究表明,油气田上方的微磁乒常具有复杂多样的成因:(1)从烃类获得代谢能的硫酸盐还原茵的作用;(2)烃类的微生物降解作用;(3)硫化环境中形成的磁黄铁矿;(4)泥质岩中富铁粘土的自生菱铁矿化;(5)与油气源岩露头或油气藏渗漏有关的自燃变质带。此外,烃类在陆相红层中的磁效应可以受到赤铁矿溶离的干扰,使其磁化强度出现数量级的下降。     

青藏高原羌塘盆地重磁剖面异常与基底构造特征

以穿越羌塘盆地的实测重磁剖面数据为基础,密切结合平面重磁异常资料,通过对重磁异常特征进行分析,采用位场转换和正反演拟合计算方法,推断了羌塘盆地的基底埋深、断裂构造及盆地样式,并对盆地的油气远景进行了探讨。认为南羌塘基底埋深浅,呈台阶状,且构造复杂,北羌塘埋深深,其间的龙木错-双湖构造带有明显的重磁异常显示。     

藏北羌塘盆地胜利河油页岩干酪根特征及碳同位素指示意义

胜利河油页岩位于北羌塘盆地南部, 走向长超过34 km, 宽9 km。笔者对该油页岩各岩系干酪根进行了分离、镜鉴、元素分析和碳同位素分析, 结果表明, 该油页岩干酪根为Ⅱ型干酪根, 油页岩中干酪根含量较高, 介于15.79%~20.37%, 具有富氢少氧的特征, 其H/C和O/C比率分别为1.11~1.19和0.08~0.25, 为胜利河地区非常好的烃源岩。油页岩层干酪根13C相对富集, 具有相对较高的δ13CPDB值(-20.79‰~ -21.78‰), 与胜利河地区油页岩母源为较单一的藻类有关。藻类的大量繁殖造成了该类生物死亡埋藏速率远大于氧化速率, 在还原环境下大部分藻类还未被氧化就被埋藏, 从而保留了原始藻类略富13C的特征。胜利河油页岩的空间展布以及规模明显受古泻湖环境的控制。     

江西九江城门山铜多金属矿床土壤轻烃找矿试验

在开展城门山矿区新一轮的深部外围找矿过程中,传统的化探方法存在一定的局限性。本次工作在城门山矿区内蚀变矿化石英斑岩、矿区外围石英砂岩上方发育的土壤垂直剖面和1线、9线、J0线土壤测线中开展了系统的轻烃测量,尝试利用土壤轻烃异常示踪下伏的矿化信息。研究结果表明,除甲烷(C1)外,土壤轻烃(C2、C3、C4、C5)都能很好地示踪下伏的矿化信息,在花岗闪长斑岩(矿体)上方显示低值区,与土壤Hg气、磁化率高值形成镶嵌结构。通过对硫化物矿体上覆土壤的有机烃组分相关特征和变化规律的分析,可提出预测下伏矿体的评价指标,也有助于了解有机质在成矿作用过程中的赋存状态和演化规律。     

青藏高原羌塘盆地基底结构与南北向变化——基于一条270km反射地震剖面的认识

通过收集并重新处理已有的反射地震剖面,获得了一条南北向横贯羌塘盆地主体的270km长反射地震剖面.剖面显示;羌塘盆地可能具有元古代的基底并且南羌塘盆地较北羌塘盆地深.在南、北羌塘地壳浅部(约0～3s)变形差异较大,北羌塘褶皱变形强烈,呈现出隆凹变形相间的格局,南羌塘则相对较平缓.羌塘中央隆起之下为连贯的弧形反射,其北侧发育一个深度达8km的半地堑构造,规模较大,可为油气资源储存提供有利空间.