Density modelling of sedimentary cover, upper part of the basement using GIS Integro technologies: Sredny and Nizhnevolzhsky petroleum regions and neighbouring areas

The paper discussed density modelling of the Sredne-Nizhnevolzhsky Petroleum Region and its neighbouring areas on the basis of the GIS INTEGRO technologies. Integrated approach to density modelling comprising the sequential realization of two models as follows: Earth’s crust and upper part of the mantle up to the depth of 70 km; sedimentary cover and upper part of the crystalline Basement up to the depth of 10 km. Gravity response from the first model matches the observed gravity field. During the course of this model creation, the main structural constituents of consolidated crust and sedimentary cover, which the meaningful jump of physical properties (density, velocity, magnetisation, etc.) occurs at, were revised. Gravity field reduction conducted on the basis of the first model allowed selecting densities for the model of sedimentary cover. The authors show that the range of the reduced gravity field over the Sredne-Nizhnevolzhsky Petroleum Region is one and a half times greater than the observed range. In the sections of the density model of sedimentary cover, density distribution was compared with the spatial position of hydrocarbon field known in the region. Structural and density-related criteria, which can be used as complementary in regional prediction of hydrocarbons are determined.