2D and 3D seismic simulation for fault modeling: exploratory revision from the Gullfaks field

Abstract

2D and 3D seismic data have emerged as a key tool in the oil and gas industry to visualize and understand subsurface morphology and boundaries. In addition to providing excellent structural images, the dense sampling of 2D and 3D survey can sometimes make it possible to map reservoir quality and the distribution of hydrocarbon with well-marked limitations. Here we use 2D and 3D seismic data to map and interpret basic structures and fault lines to construct 2D and 3D base fault models of the Gullfaks field, while avoiding common pitfalls. This work also highlights important concepts and principles that allow selection, interpretation and simulation of particular areas containing hydrocarbon traps through the comparison of different maps such as time structure, amplitude and coherence. The field covers an area of approximately 50 km2 entirely confined within block 34/10 in the Norwegian sector of the North Sea. The area of the seismic lines extends to 4875 m laterally and vertically up to 4.5 s. Based on all the selected horizons, constructed maps and dominant fault construction models (2D and 3D), we show the presence of a major fault that cuts five horizons of the area of interest. The structural features include antiform and a set of extensional faults with master, antithetic and synthetic faults with opposite sense of shear (dip direction and angle ~60°). Ductile deformation at the bottom of seismic lines shows the fluctuation of amplitude of acoustic signals in seismic lines. Our results demonstrate uplift along the major fault during extension indicated by chaotic distortion at the bottom, which reveals a gas trap. In the Gullfaks field, termination of fault movement and subsequent deformation appears to have occurred for a long period of time. This illustrates the use of 2D and 3D visualization with horizon attributes that can conveniently provide massive amounts of data which elucidates the trapping mechanism of faults.