Impacts of complex geological structures on marine controlled-source electromagnetic responses
Impacts of complex geological structures on marine controlled-source electromagnetic responses
复制标题
复杂地质结构对海洋受控源电磁响应的影响
DOI：
10.1016/j.jappgeo.2020.104126
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发表时间：
2020-09
影响因子：
2
通讯作者：
Jie Lu
中科院分区：
文献类型：
--
作者：
Jiankai Li;Ying Liu;Bo Han;Jie Lu
褶皱和断裂是地质构造中最常见的基本构造类型。海洋可控源电磁（CSEM）数据受到海底地质环境中褶皱、断层和其他复杂不规则地质构造的强烈影响，因为它们的电性各向异性以及这些构造产生的测深特性。在这项工作中，我们研究了两种典型的地质构造，褶皱和断层，对海洋CSEM响应的影响，采用自适应有限元建模方法。在我们的代码中采用非结构化的四面体网格，可以轻松地包含复杂的模型几何形状，从而可以将自然环境真实地映射到模型中。在褶皱模式上，研究了背斜、向斜和混合背斜-向斜型构造的影响；数值计算结果表明，背斜和向斜都会产生相当大的负电磁异常，这些负电磁异常可在一定程度上被高阻目标储层的正电磁异常抵消。向斜的响应曲线呈“W”形，其中心部分为上升的正异常，在解释CSEM数据时可能被误认为是高阻储层的响应。背斜/向斜引起的负异常随背斜/向斜肢体倾角的增大而增大。对于断层模型，我们研究了断层断层和地堑对海洋CSEM响应的影响，结果表明断层断层/地堑的响应可以大到足以掩盖目标储层的响应。我们的结论是，褶皱和断层显然必须被考虑在内，以避免对海洋CSEM数据的误解。
Abstract Folds and faults are the most common types of basic structures in geological formations. Marine controlled-source electromagnetic (CSEM) data are strongly affected by folds, faults and other complex irregular geological structures in subsea geo-environments because of their electrical anisotropy and the bathymetry generated by these types of structures. In this work, we investigate the effects of two typical geological structures, folds and faults, on marine CSEM responses by using an adaptive finite-element modeling approach. The adoption of unstructured tetrahedral grids in our code easily allows the inclusion of complex model geometries so that natural environments can be mapped into the model realistically. For the fold models, we investigate the impacts of anticlines, synclines and mixed anticline-syncline-type structures; numerical results indicate that both anticlines and synclines can produce considerable negative electromagnetic anomalies, which may be neutralized to a certain extent by the positive electromagnetic anomalies of a highly resistive target reservoir. The response curve of a syncline displays a “W” shape whose central part consisting of rising positive anomalies may be mistaken as the response of a highly resistive reservoir when interpreting CSEM data. Furthermore, the negative anomalies caused by the anticlines/synclines increase with the increasing inclination of their limbs. For the fault models, we investigate the effects of horsts and grabens on marine CSEM responses and results show that the responses of horsts/grabens can be large enough to mask the target reservoir's response. We conclude that folds and faults clearly have to be taken into account to avoid the misinterpretation of marine CSEM data.
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DOI：
--
发表时间：
2007
期刊：
--
影响因子：
--
作者：
M. Darnet;M. Choo;R. Plessix;M. Rosenquist;Kok Yip-Cheong;Eldon Sims;John W. K. Voon
通讯作者：
M. Darnet;M. Choo;R. Plessix;M. Rosenquist;Kok Yip-Cheong;Eldon Sims;John W. K. Voon
影响因子：
3.3
作者：
S. Davydycheva;M. Frenkel
通讯作者：
S. Davydycheva;M. Frenkel
影响因子：
3.3
作者：
Constable, Steven
通讯作者：
Constable, Steven
DOI：
10.1190/1.3255845
发表时间：
2009
期刊：
Seg Technical Program Expanded Abstracts
影响因子：
--
作者：
C. Schwarzbach;Ralph-Uwe Börner;K. Spitzer
通讯作者：
C. Schwarzbach;Ralph-Uwe Börner;K. Spitzer
DOI：
--
发表时间：
2007
期刊：
--
影响因子：
--
作者：
S. Constable;L. Srnka
通讯作者：
S. Constable;L. Srnka