METHOD TO DETERMINE PERMEABILITY AND POROSITY OF OIL-SATURATED RESERVOIRS Russian patent published in 2008 - IPC E21B47/10 

FIELD: oil and gas production, particularly to investigate collecting properties of productive reservoirs to determine available reservoir porosity and permeability values at all oil and gas field development stages, for instance during selecting and usage of oil-extraction methods, oil resource calculation and so on.

SUBSTANCE: method involves operating injection and producing wells; performing petrophysical core investigations, as well as geophysical and hydrodynamic well survey; plotting correlative dependences of corresponding parameters from said survey; carrying out well interference testing; determining optimal well operation regimes and operating oil-and gas-saturated thicknesses involved in filtration. Hydrodynamic well survey is performed at steady or unsteady filtering regimes. Basic permeability and porosity reservoir parameters are determined and optimal bottom-hole pressure values are set for current deposit during product extraction and reagent injection. Wells are shifted into operation regime with optimal bottom-hole pressure values. After that well interference testing is carried-out at optimal bottom-hole pressure and reservoir thickness involved in filtration between exciting and observing wells is determined from a given mathematical relationship. Threshold permeability value providing right equation side equality or near equality to left equation side corresponding to reservoir thickness operating during survey between exciting and observing wells is calculated beginning from minimal thickness values in ascending order by serially subtracting calculated thickness from total oil- and gas-saturated reservoir thickness between wells under survey. Finally threshold porosity value corresponding to said threshold permeability value is determined from test porosity-permeability correlation dependence.

EFFECT: increased accuracy of determination of operating reservoir thickness involves in filtering in crosswell areas with filtration regimes optimal for said parameters, possibility to determine minimal available reservoir porosity and permeability values corresponding to said operating reservoir thickness.

7 cl, 3 tbl