Abstract: Solid particles are colored with a cationic dye and at least three calibration standards having different known mass concentrations of the colored particles are prepared. A digital analysis of the images of the calibration standards is carried out based on an additive RGB color model and intensity distribution profiles of red, green and blue colors are obtained for each calibration standard. A single norm function is selected to characterize quantitatively changes in the red, green and blue colors in all calibration standards. A single calibration curve is obtained by comparing values of the selected norm function for each calibration standard with a known mass concentration of the colored particles in this calibration standard. A suspension of the colored solid particles is injected through a porous medium sample and the sample is split into two parts along a suspension flow direction.

Abstract: A suspension of a contaminant comprising at least one solid component and colored with at least one cationic dye is prepared. The suspension is injected through a sample of the porous medium and the sample is then split. A distribution and a profile of the contaminant in the sample is determined on the basis of a distribution and an intensity of the at least one cationic dye.

Abstract: A porous medium sample is initially saturated with a conductive fluid, or a conductive fluid and a non-conductive fluid at the same time, or a non-conductive fluid only. Measurements of electrical resistivity are taken in at least two places along the porous medium sample, and a flooding experiment is carried out with a contaminant solution injected through the porous medium sample. During or after the filtration experiment, second measurements of resistivity are carried out at the same places where the first measurement had been made. Measured data are used for computing a profile of rock saturation with filtrate and a ratio of a modified porosity to an initial porosity of the sample.

Abstract: A suspension of a contaminant comprising at least one solid component and colored with at least one cationic dye is prepared. The suspension is injected through a sample of the porous medium and the sample is then split. A distribution and a profile of the contaminant in the sample is determined on the basis of a distribution and an intensity of the at least one cationic dye.

Abstract: A core sample is taken from a wall of a borehole and at least one core fragment is cut from the core sample. The irradiation of the core fragments is carried out with longitudinal acoustic waves and a propagation velocity of the longitudinal acoustic waves in each of the core fragments is measured. An empirical relationship between a velocity of a longitudinal acoustic wave and a porosity for a given lithological type of the rock is selected. A porosity for each core fragment is determined using the measured velocities of the longitudinal acoustic wave and the selected empirical relationship. A value for porosity change is determined by comparing the determined porosity values for the core fragments and a value of a reference porosity typical for the given lithological type of the rock.

Abstract: A source and a receiver of acoustic waves are placed on opposite surfaces of a porous medium sample. A first irradiation of at least one part of the sample with longitudinal acoustic waves is carried out. A propagation velocity of the longitudinal acoustic waves is determined. An empirical relationship between a propagation velocity of a longitudinal acoustic wave and a porosity for a given type of the porous medium based on the porosity and a saturation behavior of the sample is selected. A filtration experiment by injecting a contaminant mud through the sample is carried out. A second irradiation of the same portion of the sample with longitudinal acoustic waves is performed and a propagation velocity of the longitudinal acoustic waves is measured. A porosity change in this part of the sample is determined based on the velocities of the longitudinal acoustic waves measured prior to and after the injection of the contaminant and using the selected empirical relationship.

Abstract: A polymer solution is dried until full evaporation of water. The polymer formed after drying the polymer solution is heated up and active degradation temperature range at a given heating rate and a degree of polymer degradation within this temperature range are determined. Then the solution is dried and a thermal analysis is conducted within the temperature range including the active degradation temperature range. A loss of mass of a portion of a sample of a porous medium is calculated and a loss of mass of similar sample of the porous medium sample after pumping the polymer solution injection is also determined. Based on the derived values, weight concentration of polymer penetrated into the porous medium is determined.

Abstract: A method for determination of a spatial distribution and concentration of contrast components in a porous sample comprises the steps of scanning a sample with X-ray and obtaining a computer tomographic image of the sample. Then an area of interest inside the obtained computer tomographic image is selected and a first cross-section of the computer tomographic image is defined. Spatial distribution and concentration of contrast components inside the area of interest are determined by analyzing histograms of grayness distribution in the cross-sections of the computer tomographic image starting with the reference cross-section.

Abstract: A method for determination of a spatial distribution and concentration of contrast components in a porous sample comprises the steps of scanning a sample with X-ray and obtaining a computer tomographic image of the sample. Then an area of interest inside the obtained computer tomographic image is selected and a first cross-section of the computer tomographic image is defined. Spatial distribution and concentration of contrast components inside the area of interest are determined by analyzing histograms of grayness distribution in the cross-sections of the computer tomographic image starting with the reference cross-section.