AUTHOR=Zhang Weihao , Xie Xingbing , Zhou Lei , Wang Xinyu , Yan Liangjun 

TITLE=3-D forward modeling of shale gas fracturing dynamic monitoring using the borehole-to-ground transient electromagnetic method

JOURNAL=Frontiers in Earth Science

VOLUME=Volume 12 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2024.1394094

DOI=10.3389/feart.2024.1394094

ISSN=2296-6463

ABSTRACT=Electromagnetic methods play a crucial role in the exploration and development of unconventional oil and gas resources, with ground electromagnetic methods having been successfully employed in the dynamic monitoring of shallow to intermediate unconventional oil and gas. However, as energy development extends towards deeper layers, traditional ground-based methods face challenges. The borehole transient electromagnetic method can stimulate the underground target at a short distance by placing the emitter in the well, so as to expand the detection range and improve the resolution. In this study, a non-structured vector finite element method combined with a second-order backward Euler variable step-size difference format and the MUMPS solver are adopted to realize the threedimensional forward modeling of the transient electromagnetic fields of borehole electrical sources. Validation against finite element solutions for borehole uniform half-space, numerical solutions from COMSOL, and surface three-dimensional model confirms the correctness and accuracy of this method. The radial electric field response characteristics of downhole transient electromagnetic shale gas fracturing dynamic monitoring model are analyzed by using this algorithm, and the effectiveness of downhole transient electromagnetic method in dynamic monitoring is evaluated. The results indicate its capability to meet the geological requirements of three-dimensional model dynamic monitoring, demonstrating promising application prospects.