Abstract.

Seismic stratigraphic analysis of petroliferous sedimentary basins established extensive development of noncompensated sedimentary sequences (NSS). The NSS of long-time development form only in areas of continental high-velocity earth's crust. An explanation is given of the NSS as confined to mediterranean marine paleobasins whose area1 extent is as large as 2 to 3 mln sq km and depths down to 2 km and which do not have actual analogies. Sedimentation in such basins took place on paleobasins and the basins were predominantly filled with clinoforms that extended for hundreds of kilometres along a paleoslope. The NSS are divided into embedding sequences (NSS-I) and filling sequences (NSS-2).

Three formations can be singled out in an NSS-1: delta front formation, reefal formation and condensed sheets; while in an NSS-2 atoll formations, evaporate formations and terrigenous clinoforms can be differentiated.

The last have especially extensive development. The paper considers seismic-stratigraphic indicators for various NSS and the role they play in the generation and migration of oil and in the formation of oil fields. A new type of sedimentary bodies has been identified whose formation proceeded in the course of lateral progradation of paleoslopes termed as lanarclines. The studies of the Neocomian oil-bearing sequences of West Siberia and the Maikop formations of Cis-Caucasus provided data on which basis the regularities in the formation of reservoirs in lanarclines are brought out. Standardized approaches to make seismic-stratigraphic analysis of lanarclines are proposed by studying the spatialtemporal process of specifically identified localities.

Résumé.

Les principes de distribution des zones de sédimentation non compensées (ZSNC) ont été établis par l'analyse sismo-stratigraphique des bassins sédimentaires d'URSS. Les ZSNC ayant eu un long développement sont limités aux lieux de dépôts des bassins sédimentaires dont les profondeurs de socle dépassent 5 km. Lorsque cette profondeur se trouve dans la fourchette 1-5 km, les ZSNC correspondent aux intervalles du niveau de la mer D3 - C, J3 - K, P2 - Ni. Le volume total des ZSNC est supérieur à la moitie de la section sedimentaire.

Les ZSNC représentent l'essentiel des ressources pétrolières.

On a identifié deux types de ZSNC qui comprennent les pièges à l'intérieur des

This content is only available via PDF.
You can access this article if you purchase or spend a download.