Allen, Mark¹, Eric Blanc², Clare Davies², Adrian Heafford³, Robert Scott², Stephen Vincent², Larisa Voronova²
(1) CASP, Cambridge University, Cambridge, England
(2) CASP,
(3) Jebco, Cheam, England

ABSTRACT: Neotectonic Deformation and Hydrocarbon Accumulation in Russia

Neotectonic deformation is important in controlling hydrocarbon distribution in Russia. Many of Russia’s proven and potential hydrocarbon reserves are in traps that are young and even tectonically active, reflecting the deformation of Eurasia in response to the India-Eurasia and Arabia-Eurasia collisions, subduction of Pacific ocean crust at the east Asian margin, and interactions of the Gakkel oceanic spreading centre with the Arctic Shelf.
Examples include Sakhalin, where traps are Late Cenozoic folds, interpreted to result from oblique convergence across this area. Convergence is probably caused by stresses arising at the Pacific plate margin. Deformation also influenced sediment distribution from the Palaeo-Amur river, which supplied reservoir quality sands to fields in Sakhalin and adjacent offshore areas. Many anticlines are weakly active in the West Siberian Basin, demonstrated by drainage shifts and late Cenozoic stratigraphic pinchouts on fold crests. This folding is a key factor for trap creation. Deformation may result from far-field stresses arising from the India-Eurasia collision, although the area is relatively close to the Eurasia Basin, where the active Gakkel ridge intersects the northern margin of Eurasia. Rifting associated with this spreading centre has also created potential traps on the Laptev Shelf. Active shortening in the Greater Caucasus results from the Arabia-Eurasia collision. This has created anticlinal traps in the northern Caucasus foothills; similar targets occur in undrilled offshore folds in the eastern Black Sea. Like Sakhalin, a key issue is clastic reservoir provenance, particularly how drainage of the major rivers flowing from the Russian Platform evolved through time.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004