Abstract Hydraulic fracturing in multi-branch wells is increasingly common in unconventional reservoir development, promoting resource sharing, cost reduction, and enhanced production efficiency. Accurately determining the status of hydraulic fractures is crucial for evaluating the effectiveness of oil and gas production enhancement. However, the complex structures of wells and reservoirs complicate electromagnetic wave propagation, making long-distance electromagnetic fracture detection challenging and still insufficiently studied. To address these technical challenges, a three-dimensional numerical model for electromagnetic detection of horizontal cross-well hydraulic fractures was developed based on the finite element method (FEM) coupled with transitional boundary conditions (TBC). The conventional induction logging tool was reconfigured by incorporating a semi-arc hybrid magnetoelectric dipole as the receiving element, while the coaxial dual-coil system was arranged for radial traverse measurements. The sensitivity of electromagnetic monitoring data to fracture geometry and strike azimuth was systematically investigated for conductive-proppant-filled hydraulic fractures. Numerical results demonstrate that, under identical conditions, the novel tool configuration generates electric signal amplitudes at least two orders of magnitude higher than those of conventional counterparts, achieving a detection range of 80 m. The received signals are more sensitive to vertical fracture propagation than to lateral propagation and exhibit high sensitivity to minor variations in fracture dip and azimuthal strike, enabling precise determination of fracture-wellbore spatial configurations. Systematic electromagnetic responses to fracture geometric attributes (e.g. height and length) and orientation permit quantitative cross-well electromagnetic imaging of fracture morphology. This technology provides practical diagnostic support for optimizing multi-well stimulation strategies.
Meng et al. (Tue,) studied this question.