The hydrodynamic conditions of migration and accumulation of hydrocarbons are exemplified by the Pomorsko, Czerwiensk and Zarnowiec oil fields in Poland.
According to Hubbert, under hydrodynamic conditions a buoyancy force and moving water exert major control over the distribution of water, oil and gas in a reservoir, causing the oil/water and gas/water contact to be tilted.
In this paper, a modified theory is advanced to define more precisely the position of potential oil and gas traps. The theory introduced here is more universal than Hubbert's theory because it accepts not only the groundwater motion (dynamic effect), but also the variability of the oil, gas and water density (static effect) and heterogeneity of reservoir rocks (capillary effect).
According to the presented method, to determine potential hydrodynamic entrapment of hydrocarbon, it is necessary to construct potentiometric maps for groundwater in terms of fresh water, maps of differential energy of oil or gas with respect to groundwater and maps of differential energy of oil or gas caused by capillary forces and then to add them up by superimposition.
For determining hydrodynamic traps, Hubbert's potentiometric model of hydrocarbon accumulation is applied with its further modifications.
Potentiometric theory by M.K. Hubbert1 accounts for the influence of buoyancy force and hydrodynamic factor, related with the motion of groundwaters in a water-oil-gas bearing strata, on the locality of oil-water and gas-water contacts. M.K. Hubbert's theory disregards changes in the density of water, oil and gas, as well as the capillary pressure effect.
An original method of mapping hydrodynamic traps for oil is presented in the paper. It is a modification of the potentiometric theory by M.K. Hubbert.1 This novel approach accounts both for the influence of dynamics of groundwaters and also changes of reservoir fluids density values and the effect of capillary pressure values on the location of hydrodynamic traps. With this method it is possible to determine hydrodynamic traps location on a map, in 3D space, in the flowing water conditions.
