Abstract
<jats:p>Previously, a method was proposed by the author and colleagues for estimating the total thickness of productive intervals based on seismic background dynamics characteristics using the thermodynamic indicator TI, a measure of the degree of geoenvironmental nonequilibrium. A near-linear empirical relationship was established between TI values and the total thickness of productive intervals measured in exploratory wells using standard well logging. This relationship is observed only within a specific frequency range. Bispectral analysis of the fine structure of seismic background records allowed us to develop a method for estimating the useful frequency range and to construct the SI(f) functional, a simple indicator of the reservoir fluid saturation type (oil/water). In this paper, we propose a new method for the local estimation of productive interval thickness based on SI(f). We analyzed the same test dataset and demonstrated that the use of nonlinear seismic background characteristics also leads to a linear relationship between the total thickness of productive intervals and the reservoir saturation type indicator, averaged over the specific frequency range (SIH). A good positive correlation is observed between productivity estimates obtained by two physically independent methods, which increases the reliability of results in geological exploration, in mapping the total thickness of productive intervals, and selecting promising drilling sites. In areas without existing wells, the thickness of productive intervals is calculated in arbitrary units, and promising drilling sites are selected based on the extremes of the SIH value field. If thickness data from at least a few wells are available, the linear regression coefficient can be used to easily convert the arbitrary units into units of length.</jats:p>