Patent ID: 7819181
Filing Date: 2010-10-26
Classification: E21B,G01V

Abstract:
1. A method of evaluating a geometry of a hydraulic fracture in a rock formation penetrated by a borehole, comprising the steps of: placing a number of electric field sensors or magnetic field sensors or both electric and magnetic field sensors inside or around the borehole; injecting into the borehole an electrolyte-based fracturing fluid at a pressure high enough to allow the fluid to create the fracture in the formation penetrated by the borehole and to flow from the borehole into the fracture and from the fracture into the formation, and having a fluid resistivity and a pH high enough to ensure that a detectable electromagnetic field is generated by the flow of the fracturing fluid due to the electrokinetic effect; measuring the values of electric or magnetic fields, or both electric and magnetic fields generated by the flow of the fracturing fluid from the borehole into the fracture and from the fracture into the formation due to the electrokinetic effect; and determining the geometry of the fracture from the measured values.