深地/深海探测中强电流激发下可控源电磁法激电效应机理研究及应用

With the implementation of deep underground/sea exploration strategy in China, new requirements for electromagnetic exploration technology have been put forward. Currently, the controllable-source electromagnetic（CSEM） method applied to deep targets for oil and gas exploration focuses on resistivity anomalies, but the induced polarization (IP) effect is often “abandoned”, which could detect reservoirs and improve detecting precision. Therefore, it is necessary to focus on the two basic scientific problems that are the IP effect of the equivalent model of multiphase porous medium with complex resistivity which are excited by high-power strong current and the theory of CSEM exploration of oil and gas detection. We plan to use a series of effective methods, which include mechanism research, experimental test and analysis, model iteration and simulation calculation, and so on, to supplement the CSEM theoretical method which adapted to the complex resistivity of deep target rate of oil and gas detection, also, to analysis of CSEM response characteristics based on integrated equivalent model. It is very important to understand the IP mechanism of CSEM method and to perfect relevant theories.

随着我国深地深海探测战略的实施,对电磁勘探技术提出了新要求。但是,目前可控源电磁法主要研究电阻率率异常,而激发极化效应(IP效应)常常被“遗弃”,这类IP效应识别出来可以检测油气藏并提高探测精度。因此，针对大功率强电流激发下多相孔隙介质激发极化机理和可控源电磁勘探油气检测理论等两个基础科学问题，我们拟采用机理研究、实验测试分析、模型迭代及模拟计算等方法，补充完善适应于深层目标的深地深海可控源电磁法复电阻率油气检测理论方法，分析基于一体化等效模型的电磁响应特征。这对搞清可控源电磁法激发极化机理及完善相关探测理论都有十分重要的科学意义和实用价值。

随着我国深地深海探测战略的实施,对大功率可控源电磁法提出了新要求。但是,目前可控源电磁法中激发极化效应没有充分利用并发挥作用。因此，本项目主要针对多相孔隙介质激发极化的机理、表征和应用等开展研究。.通过对孔隙介质频散测试及模拟分析，发现电阻率、极化率随含油饱和度的变化呈现分段的线性特征，低饱和度区呈现平缓线性特征，而高饱和度区呈现陡立变化特征。基于此，创新提出采用分段函数来表征含油饱和度与复电阻率关系，应用表明能够提高电磁法对储层含油气识别精度。 .创新提出考虑激电效应的电磁法储层饱和度评价方法。储层岩石孔隙介质含油气后会产生激发极化效应，通过模拟测试建立了岩石复电阻率与含油饱和度的确切关系。创新提出采用多种组合的复电阻率等效模型来表征岩矿石电磁频散效应特征，为更精确模拟岩矿石激发极化效应提供了一种新思路。应用实例效果表明该做法能够有助于提高电磁方法含油储层评价精度。.创新提出考虑海底储层岩石孔隙度、海水分层特征以及激发极化效应的多信息海洋可控源电磁三维建模方法。创新复电阻率分步约束反演方法，实现电阻率和极化率的分步反演和激电信息提取。为大功率可控源电磁法激电效应定量提取及储层评价奠定了基础。.首次提出了电磁属性的概念，对可控源电磁勘探电性参数按属性进行了归类，明确了时频电磁法识别油、气、水的电磁属性因子，创新提出电阻率-极化率联合的油气目标勘探思路，对推动大功率可控源电磁油气勘探应用具有重要意义。.通过模拟证明双频激电信息在海洋储层油气检测及评价中的有效性，双频激电相位解耦技术是识别薄层油气储层的有效方法，这为海洋可控源电磁提高薄层探测精度，具有一定的实用价值。.将大功率可控源电磁法激电效应的应用进一步推广到井地电磁法油气开发和重金属污染监测，通过应用表明激电效应信息能够为油田开发和环境监测发挥作用，具有重要的意义。