| Popis: |
This paper summarizes recent progress towards the goal of identifying productive vertically aligned fractures, cracks or micro-cracks in gas reservoirs using surface seismic data. Our results demonstrate that identification and interpretation of fracture trends can be more accurate by exploiting a new seismic attribute, the envelope of the anisotropic gradient, in an integrated interpretation approach. The method was applied to the Narraway gas field located on the leading edge of the Foothills Disturbed Belt in Northwest Alberta, where intersecting the fracture trends with the borehole is key to achieving a commercial well. The data are analysed to test for a relationship between the fracture density and orientation as indicated by the attribute and the actual well performance, core and logs. Commercial wells were drilled based on the results of this work, thereby validating the applied methodology. |
