Characterization of Fractured Reservoirs Using a Combination of Downhole Pressure and Self-Potential Transient Data

Figure 12

A conceptual model for different behaviors of SP changes at the country rock (A) and fractured rock (B) regions, and on the tunnel wall/floor (C). The drag current (solid line) flows only through the fracture (F) region at early times and through both of the fracture (F) and matrix (M) regions at later times than the time required for pressure equilibrium between the fracture and matrix regions. The conduction current (broken line) flows to compensate the resulting charge separation. The model is drawn for a case that KF-3 and KF-1 are observation and flowing wells, respectively; but the model is also applicable to a case that KF-1 and KF-3 are observation and flowing wells, respectively.