电磁阵列剖面法在六盘山盆地的应用效果
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摘要
六盘山盆地具有良好的石油地质基础条件，工区内的下第三系和上古生界地层为两套低阻标志层，下古生界和元古界地层构成高阻层基底。这种电性组合特征为利用EMAP法研究深层电性特征提供了前提。野外采集采用8道，观测频率选用0．001～344Hz。在资料处理中，主要采用低通空间滤波和相关技术压制高频静态位移和噪声，以增强有效信号。资料解释采用二维有限元反演、二维层状介质反演和电性界面成像技术等方法，可以分别得到相应的反演剖面和电性界面。将这些电性资料和其它有关的地质、钻井、地震和重力等资料结合在一起进行分析，便可描述断层、基底结构、局部构造，以及主要生油层特征，为进一步的勘探工作提供依据。由于EMAP法具有探测深度大，不受高阻层屏蔽的影响，对低阻层反应灵敏、施工简单灵活、成本低、见效快等特点，因此此法有可能弥补地震勘探的不足，成为六盘山盆地油气勘探中一种重要的物探方法。
Liupan Mountain basin has good petrogeologic conditions. In the explorationarea, Paleogene system and upper Palaeozoic group are two sets of low--resistivitymarker formations, and the low Palaeozoic and Proterozoic groups compose thehigh resistivity basement. This kind of electric characteristic combination offersprerequisite for studying deep electric characteristics by use of EMAP. 8 channelswill be used in field acquisition with the frequency of 0. 001--344Hi for receiving.In data processing, low--pass spatial filtering and correlation technique are used tosuppress high--frequency static displacement and noises to enhance useful signals. 2D finite element inversion, 2--D layered medium inversion and electric interfaceimaging are used in data interpretation so as to respectively obtain corresponding inversion section and electric interface. In combination with geological, drilling, seismic and gravity data, the electric data will be analysed to describe fault, basementstructure, local structure and main source bed feature, thus providing the evidencebasis for further exploration. As EMAP technique has many advantages (such asdeeper exploring depth, no shield effect from high--resistivity layer, good sensibilityto low resistivity zone, easy operation, low cost and quick returns, etc. ), thistechnique can counteract the weakness of seismic exploration and become a very important prospecting technique in hydrocarbon exploration of Liupan Mountainbasin.
Liupan Mountain basin has good petrogeologic conditions. In the explorationarea, Paleogene system and upper Palaeozoic group are two sets of low--resistivitymarker formations, and the low Palaeozoic and Proterozoic groups compose thehigh resistivity basement. This kind of electric characteristic combination offersprerequisite for studying deep electric characteristics by use of EMAP. 8 channelswill be used in field acquisition with the frequency of 0. 001--344Hi for receiving.In data processing, low--pass spatial filtering and correlation technique are used tosuppress high--frequency static displacement and noises to enhance useful signals. 2D finite element inversion, 2--D layered medium inversion and electric interfaceimaging are used in data interpretation so as to respectively obtain corresponding inversion section and electric interface. In combination with geological, drilling, seismic and gravity data, the electric data will be analysed to describe fault, basementstructure, local structure and main source bed feature, thus providing the evidencebasis for further exploration. As EMAP technique has many advantages (such asdeeper exploring depth, no shield effect from high--resistivity layer, good sensibilityto low resistivity zone, easy operation, low cost and quick returns, etc. ), thistechnique can counteract the weakness of seismic exploration and become a very important prospecting technique in hydrocarbon exploration of Liupan Mountainbasin.
引文
1Bostick F X. Electro-magnetic array profiling(EMAP). Presented at the 56th SEG Mtg, 1986
2王家映.大地电磁拟地震解释法,石油工业出版社,1995
3杨福忠等.六盘山盆地构造特征及勘探方向.勘探家(石油与天然气),1997,2(4):2～7
2王家映.大地电磁拟地震解释法,石油工业出版社,1995
3杨福忠等.六盘山盆地构造特征及勘探方向.勘探家(石油与天然气),1997,2(4):2～7
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