Johnson Jr. R.L.,ASTO Geophysical Consulting |
Scott M.P.,ASTO Geophysical Consulting |
Jeffrey R.G.,ASTO Geophysical Consulting |
Chen Z.,ASTO Geophysical Consulting |
And 3 more authors.
JPT, Journal of Petroleum Technology | Year: 2011
The hydraulic-fracture effectiveness in a coal-seam-gas reservoir from surface tiltmeter and microseismic monitoring was evaluated. Surface tiltmeters were deployed around the center of the Ridgewood fracture wells to ascertain the azimuth, dip, and volume of the created hydraulic fractures. Their positioning allowed monitoring of both horizontal- and vertical-fracture orientations, and they were arrayed around the wells to account for the expected vertical fracture direction. The estimated static rock-mechanical and derived stress properties were entered directly from the 1D mechanical Earth model (MEM), and permeability was used as a pressure history-matching parameter. The principal stresses determined by constructing the 1D MEM were very close to one another in magnitude, which suggested that hydraulic fractures may not be guided strongly in the maximum-stress direction and could follow a natural-fracture system.