Seismogeological Criteria for the Gas Potential of Aptian–Cenomanian Sediments in the North of West Siberia (by the Example of the Yubileinoe Field)1

Abstract

Abstract —Seismogeological criteria for the gas potential of the Aptian–Cenomanian sediments of West Siberia are substantiated. The research was carried out by the method of integrated interpretation of seismic materials, well logs, well test results, and petrophysical studies. As a reference object we used the Yubileinoe oil and gas condensate field located in the Nadym–Pur interfluve, in which a unique gas deposit is concentrated in the Cenomanian reservoir PK1 and the Albian sand bed PK18. Based on the research results, seismogeologic criteria for gas prediction have been formulated. Massive Cenomanian gas pools are displayed in wave seismic fields by: (1) the presence of reflectors formed at the gas–water contacts in time sections and a decrease in the amplitude parameters of the reflector G confined to the roof of Cenomanian sequence; (2) an increase in the time thickness (ΔT), a decrease in the interval velocities (Vint), and a decrease in the amplitude–energy parameters of the seismic record in the Aptian–Cenomanian sequence. Aptian–Albian sheet gas pools are displayed in the wave fields by a sharp increase in the amplitudes of the seismic record, forming “bright spot” anomalies in the time sections.