FIELD: physics.
SUBSTANCE: electromagnetic survey is carried out with a controlled source outside a region of interest which has a pre-identified geological structure suitable for containing hydrocarbons, for the range of alignment and source-receiver displacements and a first set of electromagnetic survey data is obtained. Electromagnetic survey is carried out with a controlled source inside a region of interest for the range of source-receiver displacements and a second set of electromagnetic survey data is obtained. Mathematical inversion is performed on the first set of survey data to obtain a model of underground layers outside the region of interest. The second set of survey data is processed to obtain a model of underground layers in the region of interest. During processing, the model of underground layers outside the region of interest is taken account of.
EFFECT: reduced probability of ambiguous interpretation of electromagnetic survey data.
21 cl, 14 dwg
