使用流体压差法建立根缘油气藏动态平衡

根缘油气藏(深盆油气藏) 是紧临源岩存在的烃类聚集, 是在高勘探程度下所发现的油气藏类型.由于它在成藏机理及存在方式上的特殊性, 常规意义上所采用的动力平衡方程不再适合于对其成藏平衡作用过程的分析.结合根缘油气藏地质特征及其演化特点, 采用对连续油气柱上升力的分解分析方法, 讨论了流体压差的平衡问题, 建立了位于源岩上部的根缘油气藏的动力平衡方程.      

塔里木盆地塔中、塔北地区志留系古油藏的油气运移

运用含氮化合物咔唑类探讨塔中、塔北地区在第一期成藏时志留系油气藏的烃类的运移方向, 为建立古油藏成藏模式, 预测原生油气藏分布提供依据.研究表明, 塔中志留系古油藏的油气主要来源于满加尔凹陷的中、下寒武统烃源岩, 向西南—南的方向首先进入塔中志留系, 然后沿不整合面或顺储层从北西向南东和从北东向南西2个方向向志留系在塔中地区的尖灭线附近运移.塔北志留系古油藏的油气也主要来自满加尔凹陷的中、下寒武统烃源岩, 首先向北西方向进入塔北隆起的志留系, 然后在志留系储层内或不整合面沿上倾方向继续向北西方向运移进入圈闭.      

南海海域新生代沉积盆地构造演化的动力学特征及其油气资源

通过对构造环境、地球物理场特征、盆地生储盖层发育等方面对比研究, 讨论南海南北部沉积盆地的油气资源分布特征, 为在南海进行油气勘查指明方向.目前油气勘探实践证明, 南海南部的油气资源比北部丰富, 究其原因, 南海北部为被动大陆边缘, 张性沉积盆地的烃源岩体积较小, 而南部挤压环境下形成的沉积盆地的烃源岩体积大; 北部的地热流较南部小, 因此地温梯度也较小, 如北部陆架上的珠江口盆地的热流值在5 3~ 87mW /m2之间, 平均6 7mW /m2, 而南海南部大曾母盆地平均热流值达97mW /m2, 最大值达130mW /m2, 故南部边缘烃源岩的成熟度比北部高; 由于南部边缘处于挤压构造环境, 因此在沉积盆地中形成了许多挤压构造, 而北部边缘一直处于张性构造环境, 形成的构造较少且较小; 同时, 南部边缘沉积盆地中, 烃源岩生烃与构造形成在时间上搭配较好.因此, 在南海南部边缘沉积盆地中形成了许多大型油气田, 而南海北部边缘沉积盆地中, 大型油气田较少, 中小型油气田较多.这就是为什么南海南部边缘的油气资源比北部丰富的地质原因.      

北部湾盆地涠西南凹陷超压系统与油气运移

利用地震层速度、声波测井及各种录井资料研究北部湾盆地涠西南凹陷超压系统及油气运移 ,用以指导下一步油气勘探。研究发现主要生烃层段流沙港组二段泥岩的欠压实是形成异常高压的主要原因 ,异常压力主要分布于凹陷中心地区。最大压力封闭点及油的成熟门限深度可以区分异常高压层的作用 ,在生油门限以下的异常压力带中的快速压实段 ,是油气初次运移最有利的层段。研究发现本区存在两种油气运移方式 ,即向泥岩下方运移和侧向运移 ,最后指出勘探油气的有利地区     

油气勘探中遥感方法新进展与趋向

:文中介绍了遥感在油气勘探中的最新应用 :( 1)以遥感为主线的油气勘探集成技术应用 ,包括油气遥感直接勘探研究与应用、小型及隐蔽油气藏遥感间接勘探应用和钻探靶区的遥感、物探和化探综合评价 3个阶段的应用层次。 ( 2 )以高分辨率遥感数据与GIS技术相结合进行储层裂缝识别与有利含油气区块评价。未来几年的遥感技术将有更大的突破 ,表现在 :( 1)超光谱卫星遥感与直接探测地表油气微渗漏蚀变矿物 ;( 2 )热遥感成像资料等在油气直接勘探中的应用 ;( 3)卫星雷达干涉测量技术与重力资料相结合的油气勘探应用。     

TECTONIC FEATURES AND HYDROCARBON POTENTIAL OF THE EASTERN QAIDAM BASIN

TECTONIC FEATURES AND HYDROCARBON POTENTIAL OF THE EASTERN QAIDAM BASIN     

Gladstone, Australia Field Studies: Weathering and Degradation of Hydrocarbons in Oiled Mangrove and Salt Marsh Sediments With and Without the Application of an Experimental Bioremediation Protocol

This field study was a combined chemical and biological investigation of the relative rates of weathering and biodegradation of oil spilled in sediments and testing the influence of a bioremediation protocol. The aim of the chemistry work presented here was to determine whether the bioremediation protocol affected the rate of penetration, dissipation or long-term retention of a medium range crude oil (Gippsland) and a Bunker C oil stranded in tropical Rhizophora sp. mangrove and Halosarcia sp. salt marsh environments. Permission for the planned oil spills was granted in the Port Authority area of Gladstone, Queensland (Australia). Sediment cores from three replicate plots of each treatment for mangroves and four replicate plots for the salt marsh (oil only and oil plus bioremediation) were analysed for total hydrocarbons (THC) and for individual alkane markers using gas chromatography with flame ionization detection (GC–FID). Sediments were collected at day 2, then 1, 2, 5 or 6 and 12 or 13 months post-spill for mangroves and day 2, 1, 3 and 9 months post-spill for salt marshes. Over this time, hydrocarbons in all of the oil treated plots decreased exponentially. There was no statistical difference in initial oil concentrations, penetration of oil to depth, or in the rates of oil dissipation between untreated oil and bioremediated oil in the mangrove plots. The salt marsh plots treated with the waxy Gippsland oil showed a faster rate of biodegradation of the oil in the bioremediated plots. In this case only, the degradation rate significantly impacted the mass balance of remaining oil. The Bunker C oil contained only minor amounts of highly degradable n-alkanes and bioremediation did not significantly impact its rate of loss in the salt marsh sediments. At the end of each experiment, there were still n-alkanes visible in the gas chromatograms of residual oils. Thus it was concluded that there was unlikely to be any change in the stable internal biomarkers of the oils over this time period. The predominant removal processes in both habitats were evaporation and dissolution, with a lag-phase of 1–2 months before the start of microbial degradation.     

Petroleum geological dynamics of Lower Paleozoic in the Ordos Basin, northwest China

Taking the hydrocarbon source rocks of Ordovician, Lower Paleozoic in the Ordos Basin as the main research object, the characteristics of petroleum geological dynamics about geohistory, geothermal history, hydrocarbon generation history and hydrocarbon expulsion history were studied by using the methods of basin numerical modeling dynamically and pool-forming dynamics. It is shown that the Ordovician strata had entirely undergone five stages of initial deposition, uplift and erosion, rapid subsidence, alternating uplift and subsidence, and differential uplift and erosion; that under the background of lower heat flow on the whole, the paleoheat flow of Ordovician strata in the basin could be divided into two large stages of relatively high heat flow values period before Cretaceous deposition and relatively low ones after it; that the thermal evolution of organic matters in the hydrocarbon source rocks of Ordovician had entered into high mature-postmature stage on the whole and the intensity of gas generated was greater than that of oil generated, the hydrocarbon being mainly natural gas; and that the curves of the intensity of oil and gas expulsion at each time unit showed the feature of multi-peak-type, the accumulative intensity of gas expulsion was greater than that of oil expulsion. Thus natural gas exploration potential is good.     

Hydrocarbon Alteration Characteristics of Soils and Mechanism for Detection by Remote Sensing in East Sichuan Area,China

The type, strength, and spatial distributions of hydrocarbon alteration of the surface soil are studied in two sections in East Sichuan area through the simultaneous analysis of soil organic geochemistry, soil mineralogy, and soil chemistry. The spectral response and remote-sensing mechanism are studied through the soil spectral analysis in the range of VIS--NIR bands. The results of this study demonstrate that long-time hydrocarbon microseepage can induce mineral and chemical alteration of surface soil, including the increase of clay-mineral content and carbonate-mineral content, the increase of ferrous-iron content, and decrease of ferric-iron content. Soil mineral components related to hydrocarbon alteration have spatial coincidence with soil organic geochemical components. Increase of clay- and carbonate-mineral contents in the soil can cause decrease of reflectance in VIS–NIR bands and increase of Landsat band ratio TM5/TM7. Increase of ferrous-iron content and decrease of ferric-iron content in the soil may cause increase of reflectance in the range of 400 nm to 600 nm, and higher reflectance of Landsat band ratios of TM1/TM3 and TM2/TM3.     

扬子及周缘地区上奥陶统-下志留统烃源岩发育环境及其控制因素

扬子地区下古生界发育了上奥陶统五峰组和下志留统龙马溪组两套有效烃源岩,查清其发育环境及其控制因素具有重要的科学理论和油气勘探意义.晚奥陶世开始,扬子地区进入碎屑岩陆棚演化阶段;五峰期-龙马溪期,扬子地区主体为局限的深水陆棚环境,总体呈现出浅水陆棚、深水陆棚、次深海共存的古地理格局.沉积体系展布和沉积演化主要受扬子陆块与华夏陆块的汇聚作用控制.扬子地区上奥陶统-下志留统烃源岩的形成与生烃母质生物的高生产力和高埋藏率、冰期-冰后期之交的气温快速转暖、海平面快速上升以及粘土矿物在有机质富集保存过程中的赋存驻留作用等密切相关.