准噶尔盆地南缘油气勘探的3个潜在领域——来自构造模型的论证

将定量化构造解析技术引入准噶尔盆地南缘的地震精细解释与三维地质建模中,提出并论证了未来油气勘探的3个潜在领域:①叠加楔形体,主要发育在第2排背斜带核部,由相互叠置的第三系构造楔组成,通常造成同一背斜的不同部位出现不同的油气水特征;②深层中生界构造,由白垩系和侏罗系内的断层转折褶皱组成,与上覆第三系构造楔是不同层次和不同序次的冲断构造;③横向转换构造,主要发育于第2排背斜带,由相邻背斜之间的构造转换作用形成。上述3类构造的识别和落实应立足于有针对性的地震部署和成像处理,如果埋藏较深,则需要通过建立三维介质模型,基于地层力学结构计算构造内部应变状态,以评估深部储集层构造裂缝发育方位、发育强度和发育密度。图9表1参37

Three potential exploration areas of Southern Junggar Basin: Arguments from structural modeling

Three potential exploration fields of the southern Junggar Basin are proposed and discussed through seismic structural interpretation and three-dimensional geological modeling,in which the quantitative structural analysis techniques are used.The first field is Tertiary imbricate wedges in the core of the second anticlinal belt.These small-scale wedges contribute to different properties of oil,gas and water in different part of the same anticline.The second field is the deep Mesozoic structures composed of the fault-bend folds in the Jurassic-Cretaceous,which are different in sequences and levels from the overlying Tertiary wedges.The third field is the lateral transfer structures mainly in the second anticlinal belt,which are formed by transfer action between adjacent anticlines.Identification of the above three structural types must be based on pertinent seismic deployment and imagery processing.For the exploration of deep structures,a three-dimensional medium model,in which shear module,Lame’s constants and density are specified to truly represent mechanical properties of rock units,must be constructed firstly to calculate the restoration strains within the model by use of volumetric restoration technique.These strain data can help to predict the fracture azimuth,density and intensity of deep reservoirs.