Interpretation of 3D multicomponent seismic data for investigating natural fractures in the Horn River Basin, northeast British Columbia

Abdallah A. Al-Zahrani, Donald C. Lawton

A 3D multicomponent seismic dataset from the Horn River Basin was assessed for mapping fractures. The data had good fold, offset and azimuth distributions and several approaches were used to interpret the distribution of natural fractures. In addition to amplitude mapping, PP and PS curvature maps enhanced the structural interpretation of the data and enabled the lateral continuity of faults and fractures to be mapped across the area of the seismic survey. Both horizon and volume based most negative curvature were effective in mapping fault and fracture trends within both Exshaw and Muskwa shale gas targets. At the Exshaw level, the curvature shows two main fault trends: northwestsoutheast trending normal faults that dip toward the southwest, as well as northeastsouthwest strike-slip faults. At the Muskwa level, the curvature image shows different major fault trends, namely north, northeast-south, southwest (normal and reverse faults), and northwest-southeast faults. Fractures interpreted using curvature attributes are close to the major faults and their dominant trends are generally parallel to the major faults in the area.