【作者】 夏铭；

【导师】 徐国强；

【作者基本信息】 成都理工大学 ， 矿产普查与勘探， 2008， 硕士

【摘要】 塔中54井区位于塔中低凸起Ⅰ号坡折带和中央隆起带之间宽缓构造区。目前,上奥陶统良里塔格组礁滩复合体是该区块主要勘探目的层之一。通过前人研究,良里塔格组储层具有:①储层主要为孔洞型、裂缝型和裂缝-孔洞型,其中裂缝型及裂缝-孔洞型储层占到60%以上;②属低孔、低渗储层,基质孔隙度一般小于2%,渗透率小于0.5×10^-3μm²;③裂缝主要有构造缝、溶蚀缝和成岩缝,以构造缝为主,占80%以上。研究区构造平缓,整体褶曲系数低于0.01,褶皱裂缝欠发育,以断层相关裂缝为主,因此,断层裂缝对裂缝性储层发育有直接控制作用,断层裂缝研究是该地区储层研究的关键。本文利用54井区的岩心、测井及三维地震资料,通过制作合成记录标定层位,进行了相干体分析,完成了良里塔格组断裂系统的精细解释,包括小断层和层间小断层的闭合解释,编制了其顶底面断裂系统图。在精细解释基础之上,以断面脱空理论为指导,对区内断层相关裂缝进行地震剖面上的定性识别,从而展示裂缝系统的宏观发育分布特征,编制了规模较大的断层裂缝平面分布图,根据断层裂缝系统的规模将断层裂缝分为3级,从宏观上刻画断层裂缝的发育分布特征。然后,利用VSD技术对中古3井小区块进行断层裂缝的精细描述,其步骤为:①地震精细解释;②构造几何学参数提取;③时深转换与构造形变平衡处理;④VSD定量计算;最后得到小区块断层裂缝的平面分布图。在上述工作基础之上,进行了裂缝系统的综合研究与评价,得到以下认识:1)研究区断层裂缝定性识别结果与钻井结果吻合。2)研究区主要发育4个裂缝带,与研究区4个断裂系统相对应。其中B裂缝带（沿一号坡折带发育）和C裂缝带（沿研究区中部走滑断裂带发育）最大,并且在中古2井附近交汇,形成一个面积约为20平方公里的裂缝发育带。而A裂缝带对应于研究区西部的走滑断裂带,仅有小块区域裂缝相对发育。D裂缝带位于A、B、C裂缝带之间,局部裂缝发育,但为多个独立裂缝单元。3)VSD定量计算结果表明,中古3井VSD计算结果与井实际情况相符;除中古3井北西方向有一个独立构造带裂缝发育外,整个小区块断层裂缝不发育。综上,该地区的裂缝性储层主要受断层控制,利用VSD技术方法可以较好地反映裂缝的发育分布情况。更多还原

【Abstract】 The well 54 area, between the No. 1 Faulted Slope Break and the Central Uplift area, Tazhong Lower Uplift, is a broad gentle structure region, in which, at present, the reef flat complex of the Lianglitage Formation （Upper Ordovician） is one of the major exploration targets. Previous studies on the reservoir of the Lianglitage Formation had revealed that:（1）major reservoir types comprise cavity type, fractured and fractured-cavity type, but the latter two ones are predominant accounting for more than 60%; （2）this reservoir belongs to low porosity and low permeability one, with commonly matrix porosity less than 2% and permeability less than 0.5×10^-3μm²; （3）the tectonic fractures, dissolution-fractures and diagenetic-fractures are the 3 major types, but the tectonic fractures are predominant accounting for more than 80%.In the studied area, the structure is so gentle that the folding coefficient is almost less than 0. 01% resulting in the less development of fold-related fracture. Thus, these fractures occurred widely herein are mainly fault-related fracture, fault-related fracture has the direct control on the fractured-reservoir and researchers on the fault-related fracture is the most key issue for oil and gas exploration in the studied area.Based on the cores, well logging and 3-D seismic data, first, the author has calibrated the geologic horizons to seismic sections by making synthetic seismogram, and carried out fine seismic interpretation of the fault systems of the Lianglitage Formation, including the closure interpretation of minor faults within the interval, with the help of the seismic coherence techniques, followed by compiling its fault systems map of the top and bottom surfaces of the Lianglitage Formation. On the basis of above fine interpretation, under the guidance of the theory of fault detachment void space, qualitative identification on any fault-related fracture on seismic profiles has been carried out in the studied area in order to show the macro-development and distribution characteristics of the fracture systems, followed by mapping the planar distribution of those fault-related fracture which have relative large-scale. Then, well ZG3 area was chosen to conduct fine description of fault-related fracture applying the VSD （Void Space Description） technique, which involves 4 steps including （1） the fine interpretation of seismic data, （2）extracting of structural geometry parameters, （3）balance modulating on structural deformation and time-depth conversion, （4）quantitative calculation of the VSD. Lastly, the planar distribution of the fracture systems within the well ZG3 area was mapped.Based on the above-mentioned studies, comprehensive research and evaluation are conducted, main understandings are as follows:1) The result of the qualitative identification shows a good agreement with the drilling results.2) 4 fracture zones, designated as A, B, C and D, are developed in the studied area, corresponding to the 4 fault systems, respectively. The two fracture zones of B （occurring along the No. 1 Faulted Slope Break） and C （occurring along the central strike-slip fault-damaged zone） are the larger-scale ones, merging into one in the vicinity of the well ZG2, with a total area of 20 square kilometers. However, only a small extent of relative-developed fracture is developed in the A fracture zone, which is within a strike-slip fault-damaged zone west of the studied area. The D is among these 3 zones, fractures are developed partially; most of them are single fracture unit.3) The VSD result of well ZG3 area indicates that the quantitative calculation result is consistent with the actual drilling results, i. e., the fractures are poorly developed in the whole well ZG3 area except for a single fault zone NW of well ZG3.In a word, the fractured reservoir in the studied area is mainly controlled by faulting; the VSD technique is a rather good method to outline the development and distribution of fault-related fracture.更多还原