【作者】 陈海清；

【导师】 刘怀山；

【作者基本信息】 中国海洋大学 ， 海洋地球物理学， 2010， 博士

【摘要】 柴西南三维区位于柴达木盆地西南部昆仑山和阿尔金山夹持的地区,油气资源丰富,勘探潜力巨大。该区位于盆地的边缘,阿尔金山和昆仑山两大物源沉积体系发育的沉积砂体为形成各类岩性地层圈闭提供了有利条件,但区内勘探程度低、构造复杂、相变快,以及储层地震响应和测井响应不明显等问题,成为制约岩性油气藏勘探的主要因素。本文针对柴西南三维区的勘探现状和地质特点,在层位标定、对比追踪和变速时深转换的基础上,开展现今构造、构造演化史研究工作；尤其是通过系统的古构造研究,不仅为地层层序模式建立、相带划分提供了依据,也明确了古构造对岩性地层圈闭的控制作用,指明了岩性地层圈闭发育的有利区带。通过层序地层学研究建立了等时地层格架,将研究区第三系划分为3个Ⅱ级层序和7个Ⅲ级层序,指出了纵向上岩性地层圈闭发育的有利层段。通过沉积相研究,明确了不同地区各层序的沉积相类型、有利储层的分布与性质,初步预测了平面上岩性地层圈闭发育的有利区及其砂体类型。在地球物理特征深入分析的基础上,开展了岩性地层圈闭识别技术研究,首次提出了适合柴西南岩性地层研究特点的“四确定一优选”系统理论；针对不同沉积类型的砂体及其地球物理特征,建立了四种相应的识别模式,形成了相应的识别技术系列,发现了大量的岩性地层圈闭；并在有利区带和圈闭综合评价的基础上,优选目标,提出钻探部署建议,取得了较好的勘探效果和经济效益。通过本项目研究有以下几项创新点：1、首次提出了柴西南岩性地层研究的“四确定一优选”系统理论通过对柴西南三维区岩性地层圈闭地质特点、地球物理特征、地震识别与分析技术的研究,结合圈闭地质评价,首次提出了适合柴西南岩性地层勘探特点的“四确定一优选”系统理论：即古构造分析确定圈闭有利发育区：层序地层学研究确定纵向上有利层段;沉积相研究确定平面上有利储层与圈闭的发育规律；地震技术识别和确定圈闭；综合评价优选目标。与常规岩性地层圈闭识别理论方法相比,“四确定一优选”理论方法的创新点在于,把古构造研究作为一项重要的、必不可少内容,引入到岩性地层油气藏研究中,特别强调了古构造对岩性地层圈闭的控制作用。在古构造研究中,首次应用地层倾角校正方法和地层剥蚀厚度恢复方法恢复地层真厚度,第一次系统地完成了柴西南区主要目的层的古构造图件,这套图件已成为油田的基础图件,在岩性地层油气藏勘探中发挥着重要作用。建立在深入地球物理特征分析基础上的“四确定一优选”岩性地层研究系统理论,适合柴达木盆地的地质特点。2、建立了四种圈闭识别模式,形成了相应的地震识别技术系列根据岩性地层圈闭形成环境、圈闭类型、主控因素和地球物理特征的不同,首次将研究区内岩性地层圈闭划分为四种基本类型,建立了四种相应的识别模式,并形成了相应的地震识别技术系列,即：三角洲平原-前缘砂体的基于多子波地震道分解预测技术；滩坝砂和席状砂优质储层预测技术；与坡折带相关扇体识别的古构造分析与地震分析相结合的扇体识别技术；不整合面地层圈闭的地层超覆线相干加强和波峰(谷)数分析技术,以及砂岩层厚度定量分析方法。在这些技术当中,古构造分析与地震分析相结合的扇体识别技术、地层超覆线相干加强和波峰(谷)数分析技术,在同行中属于首次提出和开发使用。多子波地震道分解储层分析技术在柴达木尚属首次使用。3、技术应用效果明显,钻探效果显著本研究提出的“四确定一优选”岩性地层研究系统理论,建立的四种圈闭识别模式与相应的地震识别技术系列,在柴西南三维区的岩性地层勘探中取得了丰硕的地质成果和良好的勘探效益。研究中共发现和落实岩性和地层圈闭137个,圈闭面积946.4km2；建议井位72口,被采纳53口,其中23口获得工业油流。新发现含油面积94km2,为油田上交预测石油储量5376×104t；新增控制含油面积67.1km2；新增控制储量3566×104t；新增探明含油面积44.85km2,新增探明储量2038.08×104t。其中2009年柴达木盆地昆北地区亿吨级油田的重大发现,岩性地层油气藏研究功不可没,储量占到了总储量的43%。本研究也极大地推动了柴达木盆地岩性地层勘探的进程,以岩性地层圈闭为勘探目标的钻井数,由研究初期2006年以前的每年1～3口,增加到2009年的27口,所占总勘探井位的比重由当初的13.3%,跃升到70%。同时,本研究中提出的“四确定一优选”系统理论和岩性地层圈闭识别技术,不仅在本区得到了很好的应用,还被陆续应用到柴西北区和柴北缘地区,显示了很好的推广价值。更多还原

【Abstract】 The Southwest Chaidamu 3D survey is located between Kunlun and Aerjin mountains in the south region of west Chaidamu basin, which had been proved to be one of the most promising areas in this basin. The survey area is situated at the edge of the Basin. The sand bodies originated from Kunlun and Aerjin mountains are good for forming various kinds of lithologic stratigraphic traps. Nevertheless, the thinness of oil-baring layers, severe facies change and the weak seismic or sonic responses characterized by this area are the geological factors that hinder the exploration of lithologic stratigraphic reserviors. And what is more, the lack of effective geophysical techniques and systematical research strategy is one of the most important reasons.Aiming at the geological characteristics and the current exploration situation in the Southwest Chaidamu 3D survey area, lithologic stratigraphic reservior identification and analysis work was conducted. During the research, the contemporary tectonics and tectonic evolution had been studied to analyze a relationship between tectonics activity and lithologic traps form and development.The study of palaeo-structure not only provide the foundation for the stratigraphic sequence model building and, systems tract deposition model division and the establishment of facies classification, but importantly determine a favorable zone for the identification of lithologic and stratigraphic traps.An, isochronous stratigraphic framework was established through the study of sequence stratigraphy in the study area. The sequence developing at Tertiary in study area was divided into threeⅡsequences and sevenⅢsequences. Several favorable lithologic stratigraphic zones had been found and determined variable traps to make clearly next research.Different sedimentary facies types had been found through studying sedimentary facies. The various cycles of reservoirs distribution and reservoirs nature had been determined and then provided evidence for finding high quality good reservoir.The identification techniques and methods had been studied for lithologic stratigraphic traps to establish models of identification and analysis for Southwest Chaidamu Basin exploration basing on geophysical analysis. And the better effect had been obtained in practice.The targets had been optimized to provide drilling suggestion basing on favorable zones and lithostratigraphic traps evaluation. The better effect and economic effect had been achieved through drilling.Several innovations had been obtained through studying the project.1 the theory and methods of "four determinations and one optimization" had been proposed first theorically for lithostratigraphic strata study.In this project research, the theory of "four determinations and one optimization" had been first proposed theorically for lithologic traps study through analyzing lithologic stratigraphic trap geologic features, geophysical characteristics and seismic identificaiton and analysis combining with traps geologic evaluation, which are consisted by ancient structural analysis to determine trap favorable development areas, sequence stratigraphics study to determine the vertical favorable areas, sedimentary facies to find reservoir development law, seismic technology to identify and determine traps and comprehensive evaluation and target optimization.Compared with conventional lithological trap identification methods, the method of "four determination and one optimization" is to analyze ancient structure which is essential for lithologic reservoirs exploration. The results obtained in the practical application were very good.During palaeo-structure study, the strata dip correction had first been proposed to recover the true strata thickness. At the same time the strata erosion thickness recovery method was first used to make maps of palaeo-structure in Southwest Chaidamu Basin. At present the sets of palaeo-structure maps had become essential basic maps and played an important role in ithostratigraphic reservoirs study.2 four identificaiton models had been estabished first and the corresponding techniques and methods had been developed. During the project implementation, on the basis of study of geologic features of lithologic stratigraphic traps, four identification models had been established according to sedimentary enviornment, traps types, main controlling factors and geophysical features. Each model had been used to identify and analyze the litho stratigraphic traps and the specific technique had been built for lithologic traps identificaiton. Four technical series had been developed, which are seismic reservoir prediction based on multiwavelet seismic trace decomposition, prediction of high quality reservoirs with great thickness and good physical property, fan bodies identification and shape configuring combining ancient structural analysis with seismic facies analysis, stratigraphic overlap line coherence strengthening and peak(trough) number technique and quantitative analysis of glutenite thickness. Among these techniques, the fan bodies identification and shape configuring combining ancient structural analysis with seismic facies analysis and stratigraphic overlap line coherence strengthening and peak(trough) number technique were first developed and used. The seismic reservoir prediction based on multiwavelet seismic trace decomposition, prediction of high quality reservoirs with great thickness and good physical property were also first used and proposed.3 The significant exploration results had been otained through the techniques application. The drilling results were great.In the project study and application, the rich geologic results and better exploration effects had been obtained. In 2009 an oilfield with predicted reserves of hundred million ton, which had been found in Kunbei area in Chaidamu Basin should be contributed to lithologic and stratigraphic oil and gas reservoir studies, its reserve was accountedfor 43% of total reserves.The theory and methods of "four determinations and one optimization" proposed in the project had not only been applied best to the area, but also to the west of the Basin and the margin of north Basin, which had showed a good promotional value.In the project study and application, the rich geologic results and better exploration effects had been obtained. There were 137 lithostratigraphic traps having been found in Southwest Chaidamu Basin 3D area with traps area of 946.4km2. The proposed well were 72, among which 53 wells were adopted, and 23 wells had drilled industrial oil. The wells aimed had increased from 2-3 planed in 2006 to 27 planed in 2009, which was occupied from 13.3% to 70%.At same time when the project studied, the new discovered trap area was 103.9km2, the predicted hydrocarbon reserves was 5446.45×104t, the new controlled area bearing-hydrocarbon was 75.8km2, the new controlled reserves was 4132×104t, the new proven oil-bearing area of 37.99km2 and proven reserves was 2606.85×104t.This research project achieved the expected goals.更多还原