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本文提供了一种电磁方法作为地震方法的补充,用于类盆岭地质构造填图的史例。沿地震测线完成了366个五分量大地电磁(MT)测深点和331个时间域电磁测深点(TDEM)。由于构造的高度复杂性,地震方法暴露出许多局限性。由于同样的原因,MT方法也受到了很大干扰,因此综合采用以下三种具体的解释方法: (1)利用TDEM对资料进行传统方法静校正,以确定高频非畸变的视电阻率,从而获得校正后的阻抗张量。 (2)与静效应原理相同的区域校正方法。通过对2-DH极化建立诺谟图,将由于地垒/地堑情况下畸变的电阻率曲线转换为可用的1-D曲线。 (3)剥层法。应用该方法可以勾绘出3km深处碳酸盐岩层下的低阻中生界页岩区。在得到沿每条测线的最佳MT解释后,我们将解释结果与地震资料以及两口井的资料进行综合,确立了电阻率和声速之间的经验关系,并在时间地震剖面上绘出MT层位。毫无疑问,对于勘探工作者来说,最终获得的综合解释剖面远比单独的原始地震剖面以及精确预测的两口井更有价值。
This article provides an example of the electromagnetic method as a supplement to the seismic method for mapping geologic structures in the basin-like ridge. 366 five-component MT measurements and 331 time-domain electromagnetic soundings (TDEMs) were completed along the seismic line. Seismic methods expose many limitations due to the high complexity of the structure. For the same reason, the MT method has been greatly disturbed. Therefore, the following three specific explanations are used in combination: (1) TDMC is used to statically correct the data to determine the apparent resistivity at high frequency and without distortion The corrected impedance tensor is obtained. (2) The same area correction method as the static effect principle. By establishing a nomogram for 2-DH polarization, the resistivity curve that is distorted as a result of a barrier / grab cut is converted to an available 1-D curve. (3) Peeling method. Using this method, we can draw a low resistance Mesozoic shale area under the carbonate rock layer 3 km deep. After obtaining the best MT interpretation along each survey line, we synthesize the interpretation results with the seismic data and the data from the two wells to establish the empirical relationship between resistivity and sound velocity and plot the MT Horizons. There is no doubt that the resulting comprehensive interpretation profile for exploration workers is far more valuable than the original seismic profile alone and precisely predicted for the two wells.