Process for direct measurement of the orientation of hydraulic fractures

A method for directly measuring, from ground stress changes, the orientation of fractures induced into a formation surrounding a well bore comprising the steps of:

• Packing off, at a desired depth, a portion of a well bore wherein fracturing of the formation surrounding said well bore will be undertaken,
• positioning a plurality of stress meters around said well bore, each such stress meter being capable of and arranged to sense ground surface stress changes resultant from fracturing occuring within said well bore said ground surface stress changes being resolvable, as to magnitude and direction, into principal horizontal components of stress change at each stress meter location,
• fracturing said material around said well bore by introducing a pressure medium within the packed off area of said well bore, recording, with said stress meters, surface stress changes resultant from fracturing the material around said well bore,
• resolving said ground stress changes, as to magnitude and direction, into principal horizontal components of stress change at each stress meter location, and;
• determining from said resolved principal horizontal components of stress change the direction of the fracture.