Features of the Earth’s Crust Structure of Oil and Gas Pools of the North Sea on the Base of Magnetic Data

Now the experience in developing the geophysical model of the Earth’s crust structure is gained on the base of seismic and gravity data. It was obtained that oil-gas pools are characterized by a lithosphere horizontal lamination and the existence of intracrust layers with density and seismic wave velocity reduced. This paper is to study a deep structure specific of an oil-gas-bearing province on the base of magnetic data. Technique of the spectral-spatial analyze (SPAN) is used to differentiate weakly magnetic sedimentary rocks and to chart out basement heterogeneities. SPAN proved itself during oil-and-gas exploring in Volga-Urals, the Caspian, Siberia, the Barents and other regions. In this work the North Sea was chosen as an investigation subject. Results of systematic magnetic surveys, which were carried out by the schooner “Zarya” in 1964-1980, were used as the source data. SPAN technique was applied to analyze extended profiles intersecting 14 known oil-gas fields. Sections were constructed in the depth range from 1 to 30km. This allowed studying the magnetization distribution features of the basement and cover rocks which are characteristic for oil-gas bearing zones. Specific permeable areas stretching under oil-gas-bearing zones are revealed in the depth range from 8 to 28km.