【作者】 徐宏节；

【导师】 彭大钧；

【作者基本信息】 成都理工大学 ， 矿产普查与勘探， 2010， 博士

【摘要】 近年来火山岩储层的研究已经成为油气地质研究中的一个难点和热点。目前火山岩储层已经成为火山岩发育地区油气勘探中最重要的新领域。所以开展火山岩储层的研究具有明显的理论价值和重要的现实意义。本文以松辽盆地南部断陷层为例,在广泛调研国内外火山岩储层研究的基础上,进行了大量的野外地质调查、岩芯观察、分析化验与测试、室内编图和综合研究,并根据近几年获得的新资料,在分析研究区的构造与沉积特征之后,重点采用地球物理联合反演的方法开展火山岩储层识别及评价研究。经过一系列努力攻关,本文主要取得了以下认识及进展:(1)松辽盆地发育于海西-印支期古亚洲洋关闭形成的褶皱造山带之上,其基底发育的NNE、NNW和EW向三组深断裂,其成因和郯庐断裂系北段燕山期的大规模左行走滑活动有关。早燕山期NNE向基底断裂的大规模左行走滑活动对盆地基底进行了强烈的改造,其派生的NNE、NNW向的共轭剪破裂和在此基础上形成近SN向追踪张裂体系对断陷盆地构造几何学产生重要的控制作用。断陷期主要NNE、NNW和SN向断裂都是沿这些早期破裂面在早白垩世强烈伸展拆离作用下形成的。长岭和十屋断陷的构造演化整体均可分为断陷阶段、坳陷阶段和构造反转阶段。长岭断陷断陷期主要发育NNE、NNW和EW三个方向同沉积正断层,它们在断陷期具有强烈的伸展活动。其中NW向断裂伸展活动在火石岭期比较显著,可能是NNE向基底断裂左行走滑拉分的结果;至沙河子期和营城期转为EW向至NWW-SEE向伸展拆离,地壳伸展率超过20%,伸展量平均15km。深大断裂控制区域火山岩分布,复合断裂控制火山口分布,区域节理控制火山岩储层分布。(2)长岭、十屋凹陷断陷层内部可划分为火石岭组(K1h)、沙河子组(K1sh)、营城组(K1yc)、登娄库组(K1d)。其中前3个层系是3次断陷幕的沉积响应,后者为断坳过渡时期的沉积产物。断陷层系中发育了与裂陷背景相关的沉积体系类型,如陡坡带发育扇三角洲、水下扇,缓坡带发育辫状河三角洲,其间为湖泊沉积体系;早期发育冲积扇,晚期发育辫状河冲积平原等,它们在空间上有机配置,反映了裂谷盆地的正断层边缘和缓坡边缘分别对盆地沉积体系发育的控制作用,这就构成一个完整的盆地发育旋回。(3)长岭断陷火山岩的主要类别为流纹岩、凝灰岩、安山岩、玄武岩、火山岩角砾岩、侵入岩。长岭断陷火山岩具有两种喷发方式——中心式喷发和裂隙式喷发,并具有多期喷发的特点,火山岩相主要发育溢流相和爆发相,溢流相和爆发相在垂向上相互叠置出现。酸性岩类的流纹岩储层储集物性最好,流纹质凝灰岩次之,安山岩等中基性岩类较差。储集空间以溶孔、原生气孔、构造缝为主,其孔缝组合类型主要为裂缝―孔隙型。火山岩储层孔隙度分布在4%～10%之间,绝大多数渗透率介于0.06～0.26μm2,属于中低孔低渗-特低渗储层,火山岩的储集物性受岩性-岩相、喷发旋回、成岩作用、构造运动等控制。溢流相的上部、下部、爆发相的热碎屑流亚相以及火山岩通道相是较好的储集相带。(4)从火山机构、火山岩相、地震属性等三个不同角度对长岭断陷腰英台工区营城组的火山岩储层进行了预测,识别出18个较确切的勘探目标。基本形成了一套松南断陷层火山岩储层识别及评价技术系列。在区域构造背景分析基础上,利用地震联合解释,宏观确定火山岩分布范围;利用地震、测井、录井资料,进行火山岩体识别、单井岩相分析和岩性岩解释,研究火山岩体及其岩性、岩相特征,精细刻画勘探目标;运用属性分析、波形分类、地震反演和烃类检测等地球物理技术进行火山岩储层预测,寻找有效火山岩储层;针对松南深层火山岩岩性复杂、双重介质,通过综合研究和实际验证,选择了微电阻率扫描成像(FMI)、核磁共振(CMR-PLUS)、元素俘获测井(ECS)、偶极子声波(DSI)、阵列侧向(HRLA)等先进的测井技术来进行火山岩岩性划分、储层物性及含气性评价。更多还原

【Abstract】 The studies of volcanic reservoirs have become a difficult and hot issue in oil and gas geology research in recent years. And volcanic reservoir also has become the most important target for exploration where volcanic rocks are rich; therefore the studying of which is obviously valuable and meaningful in theory research and practical exploration. Taking the fault depression layers of southern Songliao Basin as an example, based on the study of the existing literatures on volcanic reservoir at home and abroad, we have done a lot of work on geologic field survey, core observation, testing and analysis, mapping and comprehensive research to analyze the tectonic and sedimentary features. On the basis of the above results and latest data acquired in recent years, this dissertation have use geophysical joint inversion to identity and evaluate volcanic reservoirs. After a series of efforts, this dissertation have got the conclusion and progress as follows:(1)Songliao Basin developed on the basement of Hercynian-Indosinian fold orogenic belt which was formed after paleo-Asiatic Ocean closed. Strikes of three sets of faults developed in the basement are NNE, NNW and EW, and their genesis is related to sinistral strike slip of Tanlu fault system in the period of Yanshan. The early yanshannian movement of NNE fault highly reconstructed the basin’s basement, and induced NNE, NNW conjugate shear fractures and SN tracking tension fracture system played an important role in controlling the structural geometry of rifted basin. In the period of fault depression the majority of NNE, NNW and EW faults formed in the extending and decoupling action of early Crataceous along early fracture plane. Structural evolution stages of Changling and Shiwu fault depression are totally consist of rifting stage, depression stage and the stage of tectonic inversion. In the period of rifting Changling fault depression developed syndepositional nomal faults which strikes are mainly NNE, NNW and EW with strongly extending movement, and the activity of NW trending fault was extremely obvious in Huoshiling period, which probably was caused by the sinnistral strike slip of NNE basement faults; and in the period of Shahejie and Yingcheng the movement turned to NWW-SEE trending extending and decoupling, the extension rate of crust exceeded 20% and the average amount of extension was 15km. So the distribution of volcanic rocks was obviously controlled by deep faults.(2)Fault depression layers of Changling and Shiwu Depression were composed of Huoshiling (K1h), Shahezi (K1sh), Yingcheng (K1yc) and Denglouku formation (K1d), which the first three layers formed in the three phases of depression, and the last layer formed in the transition from rift to sag. There were varieties of depositional system associated with the fault depression setting in these layers, such as fan-deltas and subagueous fans in steep slope region, braid deltas in gentle slope belt, and between them was lake depositional system; In early phase it developed alluvial fans and later was alluvial plain of braided river which were rational distributed in space. It indicates that the margins of normal faults and gentle slope in rifted basin determined the distribution and development of depositional systems, and formed a complete cycle of basin development.(3)The main types of volcanic rocks in Changling rift depression were rhyolite, tuff, andesite, basalt, volcanic breccia and irruptive rocks. And there were two types of eruption ways–eruption of central type and fissure type, which happened in multiple phases. Volcanic facies mainly contained effusive and explosive facies, and they overlapped in the vertical. Acid rocks such as rhyolite reservoirs was the best in reservoir property, then was rhyolitic tuff, andesite and other neutral-basic rocks were bad. The main reservoir pore space included dissolved pore, primary air void and structural fracture, and the combination type is mainly fractured–porous. With the porosity range of 4% to 6% and the permeability range of 0.06μm2 to 0.26μm2, the volcanic reservoirs in the basin are medium-low porosity and low, extra-low permeability reservoirs. Generally, the porosity and permeability of the reservoirs are determined by lithology-facies, cycles of eruption, diagenesis and tectonic movement. The upper and lower of effusive facies, hot detrital flow of explosive facies and the aisle subfacies of volcanic rocks are relatively better favorable reservoir facies belt.(4)Studying from three different angles, volcanic apparatus, volcanic facies and seismic attributes, to predict volcanic reservoirs in Yaoyingtai area of Changling rift depression, identity 18 relatively definite exploration targets, and form a set of volcanic reservoirs identification and evaluation technology of Songnan rift depression layers. Based on the analysis of regional tectonic setting, we have determined the macro distribution of volcanic rocks utilizing seismic integrated interpretation. Using seismic, well logging data to identity volcanic massif, analyze and interpret single well facies, then study the volcanic massif itself, the lithological and facies characters for accurately describing the exploration targets. We have carried out the prediction of volcanic reservoirs to find effective reservoirs through making use of geophysical technology, such as attribute analysis, waveform analysis, seismic inversion, hydrocarbon detection and so on. Because the deep volcanic rocks have complex lithology and dual media, we utilize the advanced technologies of micro- resistivity scanning imagery (FMI), nuclear magnetic resonance (CMR-PLUS), element capture service (ECS), dipole sonic imager (DSI), array lateral electric-logging (HRLA) etc. to classify the volcanic rocks lithology and evaluate reservoirs physical property and gas potential.更多还原