The correlation between fluid-dynamic process and petroleum potential of deep horizons in the North of Western Siberia

The article describes the results of the analysis of borehole and seismic information about the abnormally high formation pressure in the Achimov and Tyumen formations in the territory of the activities of “Gazprom” in Western Siberia. The evidence to prove that the “inversion ring structures” are kinematic anomaliesof the seismic records that related tothe processes of jet vertical migration of fluids is given. The connection between the value of the reservoir pressure,the activity of the processes of vertical migration of deep hydrocarbon gases, the tectonic structure of basin and petroleum potential is shown. High prospects to increase hydrocarbon reserves with the wide distribution of the reservoirs with abnormal high pressure, petroleum potential of which is not controlled by the structural plan are shown.
Materials and methods
Analysis of well-testing data, geophysical research wells data (349 wells) and CDP- seismic data (3D, 2D) on license blocks of“Gazprom” in the Yamal-Nenets Autonomous district and adjacent areas.
Results
The analysis of borehole and seismic data about the abnormally high formation pressure in the Achimov and Tyumen formations at the license areas of “Gazprom” in the Yamal-Nenets Autonomous district. Scientific and practical insights are done.
Сonclusions
1. “Inversion ring structures” are kinematic anomalies of the seismic records associated with channels of jet vertical migration of hydrocarbon gases and Abnormally high formation pressure. Such objects are accompanied by amulti-Deposit formations deposits of hydrocarbons ("shashlyk" - type deposits) in upper Cretaceous, lower Cretaceousand Jurassic sediments, but, on the other hand, “Inversion ring structures” are zones technological risk during drilling.
2. The main features of fluid pressure distribution are found: the increase of pressure with depth in well cross-section,the regional increase of pressure to the arched parts of the pool, a local increase in of pressure to the vaults anticlinal uplifts.
3. The connection of abnormally high pressure in the Northern region with the tectonic of the basin, and petroleum potential is found (active subsidence in the Mesozoic, intense neotectonic uplift, gas content).
4. The area of abnormally high pressure in the Northern and Arctic regions of Western Siberia linked to the activity of fluid-dynamic processes. It controls the oil and gas content of lenticular reservoirs of Achimov and Tyumen formations, outside the strict according to their hypsometric position. This fact increases the prospects of finding new, large and giant deposits of hydrocarbons in these sediments.