Magnetic and gravity anomaly patterns related to hydrocarbon fields in northern West Siberia

Abstract

A study of the features of gravity and magnetic fields in the vicinity of oil and gas reservoirs in West Siberia demonstrated a spatial relationship with the hydrocarbon deposits. The relevant magnetic and gravity anomalies cover approximately [Formula: see text] in northern West Siberia. Amplitude and frequency were investigated initially using double Fourier spectrum (DFS) analysis. This was followed by (1) application of transformations, filtering, and “moving windows” analysis; (2) compilation of maps of regional and local anomalies, and potential field derivatives; and (3) investigation of the distribution of parameters in areas of known deposits. Hydrocarbon deposits are located mostly at the slopes of positive regional gravity and magnetic anomalies which are interpreted as relating to deep riftogenic structures. At the same time, it is established that the location of hydrocarbon depositions coincides commonly with local gravity and magnetic minima generated by lows in basement density and magnetization. All known hydrocarbon deposits in northern West Siberia are in areas characterized by comparatively high gradients of constituent of gravity anomalies with a wavelength of about 90–100 km. These newly revealed links between reservoirs and potential field parameters may be a means to predict new discoveries in poorly explored territories and seas, primarily in Russia's Arctic shelf.