地震属性在英买力地区火成岩描述中的应用

Application of seismic attributes in describing Igneous rock in Yingmaili area

塔里木盆地古生界火成岩十分发育,但由于埋藏深,厚度、岩性、产状横向变化大,再加上地表地质条件较差。地震资料的信噪比较低,因此,火成岩识别比较困难。为此,在塔里木盆地英买力地区,利用三维地震资料开展了地震属性分析技术识别火成岩方法研究。在英买力地区,火成岩与碳酸盐岩为共生状态,两种地层的速度十分接近,用常规速度分析方法难以将它们区分。利用地震相分析方法对火成岩的地震相进行了划分,在地震剖面上火成岩具有板状、弧状、蘑菇状、丘状等特征；利用地震振幅属性对火成岩的反射特征进行了分析,在地震剖面上火成岩的内幕反射表现为弱振幅；综合利用分频技术以及相干数据体和三维地震资料的时间切片对火成岩的地震响应特征和平面分布特征进行了描述。对英买力地区火成岩的形态和空间展布规律进行了预测,建立了火成岩发育模式。

The igneous rock of Palaeozoic in Tarim basin is well devel- oped.Being deep in buried depth and great horizontal change in thickness,lithology,and attitude,and bad in surface geological condition,the igneous rock is quite low in signal-to-noise ratio of its seismic data,making the igneous rock very difficult to be recog- nized.Therefore,in Yingmaili area of Tarim basin,the seismic at- tributes parsing technique is studied to recognize the igneous rock through using 3D seismic data.Because the igneous rock and the carbonate rock coexist in this area,the horizon velocity of the two formations is nearly the same,making the conventional methods unable to distinguish them.So the seismic facies analysis method was used to classify the seismic facies of the igneous rock.The re- sult shows that the igneous rock is characterized by slabby,bow, mushroom and moundy in profiles.The reflecting features of the igneous rock were analyzed through seismic amplitude properties, indicating that the inside-story reflection of the igneous rock shows weak amplitude.The frequency technique and the time slice of co- herent data volumes and 3D seismic data were comprehensively uti- lized to describe the seismic response characteristics and surface distribution features of the igneous rocks.The shape of the igneous rock and its space extending rules in Yingmaili area were predicted and the development pattern of the igneous rock was established.