低信噪比复杂断块区地震资料解释

The Seismic Data Interpretation of Low SNR Complicated Fault Block Area in Tabei Region of the Subei Basin

地震资料低信噪比一直是影响地震解释方案可靠性的主要因素之一。以塔北低信噪比复杂断块区为例 ,研究低信噪比复杂断块区的解释思路和方法。该区地下地层破碎 ,断裂复杂 ,地震资料的信噪比总体较低 ,主要表现为 :地震反射不连续 ,反射能量弱 ;T31 地震反射特征可对比性差 ,T33 反射特征横向有变化 ;断面及断点反射不清 ;具多产状干扰。针对这些问题 ,提出了相应的解决对策 ,主要做了速度分析、全三维解释、深度校正等研究 ,基本上解决了地层层位的落实和断层识别这 2个在复杂断块区地震资料解释中所要解决的主要问题。通过对塔北低信噪比复杂断块区的地震资料解释 ,落实了塔 8反向断鼻构造 ,并通过了井位论证 ,实钻 ,塔x8井在E1 f2 地层见良好油气显示。

The low SNR of seismic data is one of the main factors that work on the reliability of seismic interpretation. The complicated fault block area with low SNR in Tabei region of the Subei Basin is a good example to study and sum up the interpreting methods in the complicated fault block area. The feature of Tabei region of the Subei Basin includes underground rock disintegration, complicated fault block, the general low SNR. There comes forth four obvious problems when carrying out seismic interpretation:1.the discontinuity and the weak energy of seismic reflection;2. the bad comparability of the T 1 3 reflectance signature and transverse variety of T 3 3 reflectance signature;3.the unclarity of fault surface and breakpoint;4.the disturbance of multi-attitude. Aiming at the above problems, applying the corresponding countermeasures such as velocity analysis, full 3-D interpretation and depth correction, the two basic questions of the identification of stratigraphic horizons and the detection of faults were basically solved. Both questions are the main tough problems during the seismic data interpretation. After the seismic interpretation of low SNR complicated fault block area in Tabei region of the Subei Basin, the Ta-8 reverse nose structure was identified and well location demonstration was passed. And the real drilling illustrates the favorable evidences of oil and gas in the E 1 f 2 layer of well Ta-8.