RESURVEY ANALYSIS BASED ON ELECTROMAGNETIC EXPLORATION DATA Russian patent published in 2011 - IPC G01V3/12 

FIELD: physics.

SUBSTANCE: electromagnetic exploration data are obtained on the line of motion of the source, as well as data outside the line of motion of the source. The data contain at least one electromagnetic field component which is primarily sensitive to vertical resistivity and another component which is primarily sensitive to horizontal resistivity. When using a source in form of a horizontal electric dipole, measurements of components E_z on the line of motion of the source and components H_z outside the line of motion of the source are preferred. For a source in form of a horizontal magnetic dipole, data on component H_z on the line of motion of the source and data on component E_z outside the line of motion of the source are preferred. Maxwell equations are solved by solving the direct problem or inverse problem using underground layer resistivity models which are either isotropic or anisotropic. Fluid saturation is determined from values of vertical resistivity and horizontal resistivity using empirical relationships or models of physical properties of the rock.

EFFECT: possibility of evaluating and monitoring oil and gas saturation in three-dimensional space based on electrical anisotropy.

26 cl, 6 dwg