摘要
本文主要基于频率域理论分析了激电效应与电磁感应的分离方法及相关施工方法技术,但相关理论及方法技术同样适用于时间域电磁相关问题。电磁法在识别深部目标是否含流体方面具有天然优势,研究高精度储层流体电磁检测技术对油气田勘探开发具有重要意义。基于毛管模型与电化学理论,认为极化电场与流体浓度以及微观电荷迁移和积累密切相关,且具有时间依赖性和频率依赖性。通过电扩散假说和薄膜极化理论,可以解释极化效应的本质。基于麦克斯韦方程组和等效复电阻率模型,导出电磁油气检测的基本公式,进一步分析了相关参数对准确表征油气储层的电性异常,特别是与储层含油气相关的激发极化效应在电磁场振幅和相位曲线的表现。实际工作中需要通过优化收发距、频率等施工参数,有效提取激发极化效应,从而识别油气储层的分布。通过数值模拟分析了激发极化效应在电磁场相位及微分曲线上的特征,与理论数学表征相呼应,提出了适用于储层激发极化效应的数据采集有效参数和临界频率的计算方法。最后,讨论了该方法在流体检测中的适用性,提出了基于特征曲线的施工方法和技术,为电磁法油气检测的实际应用提供了理论支持。
Electromagnetic methods are naturally superior in identifying whether deep targets contain fluids.It is of great significance for oil and gas field exploration and development to study high-precision electromagnetic detection technology for reservoir fluids.Based on the capillary model and electrochemical theory,we consider that the polarized electric field is closely related to fluid concentration,microscopic charge migration,and accu-mulation,and has time and frequency dependencies.The essence of polarization effects can be explained through the electric diffusion hypothesis and thin film polarization theory.Based on Maxwell’s equations and the equivalent complex resistivity model,we derive the basic formula for electromagnetic hydrocarbon detec-tion.The accurate characterization of electrical anomalies in oil and gas reservoirs by relevant parameters is fur-ther analyzed,especially the performance of induced polarization effects related to oil and gas content in electro-magnetic field amplitude and phase curves.In practice,the induced polarization effect can be effectively ex-tracted and the distribution of oil and gas reservoirs can be identified only by optimizing parameters such as trans-mission and reception distance and frequency.At last,we analyze the characteristics of the induced polarization effect on electromagnetic field phase and differential curves through numerical simulation,which is consistent with theoretical mathematical characterization.We clarify the effective parameters and critical frequency for data acquisition of the induced polarization effect in reservoirs.Finally,we discuss the applicability of this method in fluid detection and propose a construction method technology based on characteristic curves,provi-ding theoretical support for the practical application of electromagnetic hydrocarbon detection.
作者
何展翔
陈涛
陈本池
石艳玲
刘雪军
陈晓非
HE Zhanxiang;CHEN Tao;CHEN Benchi;SHI Yanling;LIU Xuejun;CHEN Xiaofei(Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,Guangdong 518055,China;College of Geophysics,China University of Petroleum(Beijing),Beijing 102249,China;Department of Science and Technology,SINOPEC,Beijing 100728,China;GME&Geochemical Surveys Management,BGP,CNPC,Zhuozhou,Hebei 072751,China)
出处
《石油地球物理勘探》
北大核心
2025年第4期1032-1045,共14页
Oil Geophysical Prospecting
基金
国家自然科学基金项目“海域可燃冰储层激电效应及可控源电磁数据的反演提取”(42474108)
广东省地球物理高精度成像技术重点实验室(2022B1212010002)
深圳市深远海油气勘探技术重点实验室(ZDSYS20190902093007855)联合资助。
关键词
时频电磁法
油气检测
参数优化
激发极化效应
双电层效应
time-frequency electromagnetic method
hydrocarbon detection
parameter optimization
induced po-larization effect
electrical double-layer effect
