MODERNIZATION OF THE METHOD FOR DETERMINING CAPILLARY PRESSURE AND PERMEABILITY USING AN EXPERIMENTAL LABORATORY BENCH

Abstract

This work is devoted to an experimental study of determining the value of capillary pressure in rock samples of various sizes and properties and its relationship with rock permeability. The relationship between permeability and capillary pressure has always been an important issue in rock mechanics and petroleum engineering. In the oil and gas industry, for hydrocarbon recovery, permeability and capillary pressure are two of the most important properties that dominate the production process. Permeability estimation reflects reservoir characteristics, oil and gas production, and field development design. The proposed mathematical model shows the relationship between capillary pressure and permeability, and from this we can predict the value of capillary pressure from the range of permeability values and other petrophysical parameters. The experiment was conducted as follows. First, the bottom of the cylinder was sealed with two layers of rubber ring, one clamp, and then, attaching a tube at the ends of the wetting phase, the mass of sand was measured and the porosity was calculated, assuming a grain density of 2650 kg/m3. Then the copper sheet was rolled up and placed tightly inside the container, with the bottom rubber sealing ring on top. Subsequently, water was injected into the burette until the surface of the water met the top of the rubber sealing ring; then the filter and the top rubber sealing ring were placed on top. Next, the valve between the tube container and the burette was closed to prevent air from displacing the water. A sand sample was then added over the membrane. Finally, all valves were opened, and when the water level in the burette equilibrated to the height of the top of the sand, oil was slowly added to the container to increase the pressure at the sand/oil/water interface. gradually adding oil to the container so that the water level in the burette rose. The capillary pressure was calculated from the measured height of the water in the burette. Using the Cozeney-Karman equation, the internal permeability can be calculated from the particle radius and porosity of the sand sample. This experiment was repeated twelve times with grain diameters ranging from 50 to 120 microns.