Patent ID: 7769546

Claim:
A computer-implemented method of determining a horizon volume of a subsurface volume, the method comprising: obtaining computer-readable seismic information related to a subsurface volume, the obtained seismic information having data points that represent geological formations within the subsurface volume at an array of locations within the subsurface volume, wherein the parameters of the obtained information include (i) a two-dimensional position in a surface plane of the subsurface volume, and (ii) a metric related to seismic depth of the subsurface volume, and wherein the data points in the obtained seismic information are spaced along the metric related to seismic depth according to a sampling interval for the metric related to seismic depth; and determining, with a computer, a horizon volume from the obtained seismic information, wherein the horizon volume maps the obtained seismic information onto a flattened volume such that in the flattened volume, horizons represented in the obtained seismic information are shifted to be substantially coplanar with a surface defined by the horizon volume as an estimate of a single chronostratigraphic time such that the parameters of the flattened volume include (i) a two-dimensional position in the surface plane, and (ii) a metric related to chronostratigraphic time, wherein determining the horizon volume comprises: analyzing, with the computer, the obtained seismic information to identify horizons in the subsurface volume that are represented in the obtained seismic data; creating, with the computer, an initial horizon volume that orders the identified horizons by chronostratigraphic time and that associates positions within an initial flattened volume with data points included in the obtained seismic information; analyzing, with the computer, the initial horizon volume to determine whether mapping the obtained seismic information into the initial flattened volume according to the initial horizon volume would compress the obtained seismic information by more than a predetermined amount, wherein compression occurs if two data points in the obtained seismic information (i) have the same two-dimensional position in the surface plane, (ii) are mapped by the initial horizon volume into the initial flattened volume at directly adjacent positions, and (iii) have a difference in the metric related to seismic depth that is greater than the sampling interval for the metric related to seismic depth; and adjusting, with the computer, the initial horizon volume if the mapping the obtained seismic information into the initial flattened volume according to the initial horizon volume compresses the obtained seismic information by more than a predetermined amount such that mapping the obtained seismic information into an adjusted flattened volume according to the adjusted horizon volume does not compress the obtained seismic information by more than the allowable amount.