The gravity interpretation of sedimentary basins is of utmost importance in hydrocarbon
prospecting. The increasing demand of detailed interpretations using a huge number of
observations and parameters to be estimated has compelled the development of
efficient gravity inversion methods applied to this sort of geological environment. We
present a new gravity inversion method applicable to the estimation of the basement
relief of a sedimentary basin based on the linear approximation between the gravity
anomaly and the thickness of the horizontal ribbon model. The observations are
modeled by a set of juxtaposed horizontal ribbons, whose thicknesses are the
parameters to be estimated. Each observation is modeled by a set of ribbons located at
a given depth. The observations displaying smaller amplitude in absolute value are
associated with shallower sets of ribbons. This procedure enhances the estimates of
very deep basement features, which usually is not possible using the available methods
based on linear approximations. The estimates, stabilized by the first-order Tikhonov
stabilizing functional, retrieve the basement relief shape, but in a different scale from the
true relief. The knowledge of the basement depth at a single point of the basement is
then used to bring the estimated relief to the correct scale. The proposed method has
been tested on synthetic and real gravity data, and produced always similar results as
compared with the more precise nonlinear method. The proposed method, however,
required less computational time. The difference between the required computer times
increases with the number of observations and parameters.
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