The use of an integrated, real-time fracture-diagnostic instrumentation system for the control of the fracturing treatment during massive hydraulic fracturing is proposed. The use of an integrated, real-time fracture-diagnostics instrumentation system for the control of the fracturing treatment during massive hydraulic fracturing is proposed. The proposed system consists of four subsystems: an internal fracture- pressure measurement system, a fluid-flow measurement system, a borehole seismic system, and a surface-e1ectricpotential measurement system. This use of borehole seismic and surface-electric potential measurements, which are essentially away-from-the-wellbore measurements in conjunction with the use of the more commonly used types of measurements, i.e., at-the-well bore pressure and fluid flow measurements, is a distinctive feature of the composite real-time diagnostics system. Currently, the real-time capabilities of the individual subsystems are being developed, and the problems associated with their integration into a complete, computer-linked instrumentation system are being addressed.