Continuous TDEM for monitoring shale hydraulic fracturing

A Feasibility Study of Land CSEM Surveys With a Near-Casing Source for Hydraulic Fracturing Monitoring

“…= KE b (8) where 𝑬𝑬 is a vector representing the discrete electric field values on the mesh edges, 𝒃𝒃 is the discretized right-hand side, and 𝑲𝑲 is the coefficient matrix. We employed the direct solver PARDISO to solve (8), enabling us to obtain the electric field values on the edges of the grid.…”

“…With the widening application of hydraulic fracturing technology, the exploration of new methods for dynamic hydraulic fracturing monitoring has become a research focus. Time-lapse geophysical methods, as effective approaches for dynamic hydraulic fracturing monitoring, are gradually finding applications and demonstrating promising outcomes [6], [7], [8]. Seismic technology, the most developed time-lapse geophysical method [9], [10], faces challenges in hydraulic fracturing scenarios owing to the minimal impedance differences caused by fluid displacement, making data interpretation difficult.…”

Development and Consideration of 3D Transient Electromagnetic Forward Modelling for the Hydraulic Fracturing Monitoring

“…The highpower TEM method with a long wire source has the distinct advantages of high signal-to-noise ratio, considerable depth of exploration, and low cost, and it has gradually become the focus of research for deep mineral and unconventional oil and gas exploration (Di et al, 2019). Yan et al (2018) successfully applied the long-wire source TEM method to the dynamic monitoring of hydraulic fracturing in shale gas development in southern China. They captured electromagnetic signals from a depth of 3 km caused by the fracturing of a target reservoir.…”

Mechanism of Forming Low Resistivity in Shale Reservoirs

“…Fluid saturation is one of the vital factors on the gas reserves in shale [15,16], and resistivity is one of the crucial parameters for saturation evaluation during well logging, reservoir classification, and reserve calculation [17][18][19]. Oil and gas reservoirs are often characterized by high resistivity whereas water layers by low resistivity.…”