METHOD FOR PREPARING MODEL OF FORMATION WATER Russian patent published in 2023 - IPC C09K8/00 G01N33/24 G06T7/00 

FIELD: oil production.

SUBSTANCE: methods for preparing aqueous solutions of mineral salts. In the method for preparing a model of formation water, based on the assumption that after the evaporation of formation water - the solution with which the core - rock sample was initially saturated in the formation, all the mineral components included in this solution settle in the pores of the rock, a rock sample containing soluble minerals of the solid matrix and/or salt deposits in the pore space, which was initially saturated with formation water and contains at least one area not exposed to the drilling fluid, determine the amount and composition of soluble sediments in the sample and the water saturation of the sample under formation conditions. Select at least one internal area in the sample that was not exposed to the drilling fluid; the criterion for selecting this area is the absence of mechanical disturbances that could potentially lead to penetration of the drilling fluid filtrate and an irreversible change in the composition of the formation water-solution with which the core was initially saturated in the formation. A three-dimensional digital model of the selected area is constructed, reflecting the pore structure and spatial arrangement of evaporites and salt deposits within the selected area. Specify water dissolution chemistry reactions for all water-soluble minerals found in the sample. Numerical modeling of the initial saturation of the test sample with water is carried out, taking into account the dissolution of the minerals included in the sample at the required temperature and pressure until equilibrium is achieved. The final ionic composition of the aqueous solution saturating the pore space of the digital model after reaching equilibrium is determined. Prepare a solution by dissolving the calculated amount of salts in the calculated amount of water with stirring. The resulting salt solution is brought to the required thermobaric conditions.

EFFECT: obtaining a model of formation water with a composition closest to real formation water, without the need to take water samples at the field, accelerating the production and improving the quality of model formation water samples necessary for core studies.

4 cl, 1 dwg, 3 tbl