Литосфера (Nov 2019)
Development of a fluid-dynamical model (DFM) of the Yamal Novoportovsky oiland gas-condensing deposit (based on DFM seismic data interpretation)
Abstract
Research subject. The idea of forecasting fluid-dynamical parameters is based on the views connecting the processes of sedimentation, tectonogenesis and fluid flows into an active fluid-dynamical model of the “sedimentary cover–basement” system. In such models, main fluid-dynamical parameters of oil and gas collectors, i.e. penetration and the vector of the fluid flow, are functionally connected with the components of the current state of the rock massif having a discrete (block) structure. These parameters can be calculated using DFM-interpretation technology developed by the authors in their previous works.Materials and methods. For the first time, DFM results are provided for the Yamal Novoportovsky oiland gas-condensing deposit. Here, the paleozoic basement stripped at a depth of 2700–3200 m is largely represented by metamorphic schists and marbled limestones. The basement has been covered by sediments and a platform cover since the early Jurassic age. The forecast of parameters describing modern geodynamical processes was performed on the basis of a comprehensive tectonophysical analysis of major geological and geophysical data.Results. The main axes of the neo-tectonic activity of the plate complex break the area under study into a quite regular block system that reflects a right-sided shift of fundamental blocks, that, in its turn predetermines the block shift in plate complex with the turn of the shift axis by 30 degrees. The most significant oil and gas holes in terms of influx demonstrate a connection with the described scheme of block activity. Thus, practically all high-debit boreholes were drilled in active axial zones.Conclusion. The proposed scheme of block activity satisfies the general principles of geodynamics. The developed model of abnormal pressure estimations by main productive intervals shows a good agreement with the distribution oiland gas boreholes in terms of productivity. Contact zones of active blocks present a particular interest from the standpoint of selecting the location of high-debit boreholes. These zones should be taken into account when developing new oil and gas deposits.
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