Patent ID: 7677306
Filing Date: 2010-03-16
Classification: E21B

Abstract:
1. A method for estimating a fluid driven fracture volume during hydraulic fracturing treatment of a ground formation, comprising: positioning a series of tiltmeters at spaced apart tiltmeter stations at which tilt changes due the hydraulic fracturing treatment are measurable by those tiltmeters; obtaining from the tiltmeters tilt measurements at progressive times during the fracturing treatment; and deriving from the tilt measurements at each of said times an estimate of the fluid driven fracture volume and fracture orientation at that time by performing an analysis based on minimisation of misfit between the tilt measurements at each of said times and tilts predicted by a fracture model to produce estimates of the fluid driven fracture volume and fracture orientation at each of said times as the treatment is in progress; wherein the tiltmeter stations are located sufficiently far from the fracture that only the volume and orientation of the fracture have significant effect on the tilt fields; and wherein the fracture model used to derive the fracture volume and fracture orientations at each of said times is a displacement discontinuity singularity with an intensity equal to the volume of the simulated fracture.