Abstract
An infill drilling pilot test in the Lewis, Mesaverde and Dakota formations of the San Juan Basin, New Mexico, included microseismic and tiltmeter monitoring of fracture stimulations. This study looks at microseisms from eight stages in two wells using an 18-tool stacked toolstring and surface tiltmeter measurements of 23 stages in six wells, (including the microseismic wells), using a 63-site tiltmeter array. A pressure observation well also situated within the pilot area, provided key information to the interpretation of data from the Lewis fracture stages. Complex (dendritic) fracture growth observed in the Lewis formation may be controllable through modification of the injection rate. Lower injection rates encourage simple planar growth and control fracture-height growth. Shorter fracture half-lengths were observed in the lower Mesaverde stages, leading to a redesign that is currently being tested in the field. The average fracture azimuth measured in this project, N21°E, confirmed the current understanding of the stress orientation in this part of the San Juan Basin and provided confidence regarding additional infill well placement.
