How to constrain 3-D fault continuity and linkage using reflection seismicdata: A geomechanical approach

Spatial continuity and linkage of faults may substantially affect fluid flo w either by compartmentalizing the reservoir or by increasing the tortuosit y of flow pathways, whether the faults act as seals or conduits; therefore, understanding fault linkage geometry should improve reservoir flow simulat ion models and, in turn, significantly reduce the number of wells required to drain reserves. A method has been developed to infer, in three dimensions, the fault tip-li ne geometry below the seismic resolution, as well as potential fault linkag e using 3-D (three-dimensional) seismic data and geomechanical models based on elastic dislocation, A 3-D numerical model of the faulted reservoir and its surroundings is constructed using seismic interpretation, Such a model , combined With an appropriate set of boundary conditions, is used to compu te the fault slip distribution, as well as vertical displacement field. By comparing the interpreted fault slip distribution to the computed slip dist ribution adjacent to potential intersection lines, the geomechanical models can constrain the geometry of the faults and the location of the intersect ion line beta een faults, The interpreted structure contour map and theoret ical displacement field also are compared to constrain the fault geometry. Two subsurface examples from the Oseberg Syd oil field, northern North Sea, illustrate how such geomechanical analyses can increase confidence in seis mic interpretation to refine fault connectivity and reservoir compartmental ization.