The Hydrocarbon Genesis of pre-Jurassic Complex of Khanty-Mansiyskoe Oil Field

Abstract

The origin of hydrocarbon deposits in Jurassic and pre-Jurassic complexes of the Khanty-Mansiysk area, located within the Frolov depression, in the local compression zone of the West Siberian plate — the suture zone, is established. The core and crude oil of Jurassic and pre-Jurassic complexes from prospecting wells of the Khanty-Mansiyskoe field is studied. The content and molecular mass distribution of hydrocarbons, including n-alkanes, n-alkylbenzenes, naphthalene’s and phenanthrenes, is determined in bitumen of rocks and oils by chromatography-mass spectrometry. Lithological and petrographic characteristics of rocks is determined by optical microscopy. For oil deposits of the pre-Jurassic complex “source of hydrocarbons” is not reliably established, the parent rocks were not clearly identified in this research. In the lower horizons of the Jurassic section, there is a layer of highly permeable gritstone of the Gorely formation, in which organic matter is localized, presumably making the main contribution to the hydrocarbon deposits of the lower Jurassic and pre-Jurassic complexes. As a possible “source of Paleozoic oil”, it is proposed to collect hydrocarbons from scattered organic matter of Paleozoic rocks at a significant depth (not covered by core drilling) in the areas of tectonic block crushing of foundation.