Studies of possibility for search of gas condensates in promising marine anticline structure by low-frequency electromagnetic survey method by an example of Shtokman deposit in the Barents Sea
© E.P. Velikhov, M.S. Zhdanov, M.S. Kruglyakov, S.M. Korotayev,
D.A. Orekhova, Yu.G. Shchors
Opportunities of the low-frequency electromagnetic survey for search of deposits of hydrocarbons in perspective anticline structures were studied by an example of well studied Shtokman gas condensate deposit. The problem was solved using three-dimensional mathematical modeling by the integral equation method. In the points located at the bottom of the sea on the area above the anticline, all six components of the electromagnetic field were calculated for various ways of inducing primary field by artificial controlled electric source on various frequencies in the range 0,01-10 Hz in two cases: presence and absence of hydrocarbons in the collector. It was required to establish, whether there is enough distinction in resistance of rather thin hydrocarbon layer and the host rock to diagnose the presence of a deposit, and if yes, what are the most informative components of the field and parameters of the source (orientation, frequency, distance). A horizontal arrangement of the source with direction of the axis of the source to the center of the deposit and measurement of the vertical electric component of the field has appeared to be the most effective.