Patent RU-2751301-C1 (RU)
Title: Cell for study of phase equilibrium in gas-liquid system (variants)
Inventor: GABITOV FARIZAN RAKIBOVICH
IPC: E21C39/00
Filed: 2020-12-01
Granted: 2021-07-13
Abstract: FIELD: oil industry. 
     SUBSTANCE: invention relates to the study of properties that characterize the thermodynamic phase equilibrium in gas-liquid systems, including at high pressures and temperatures, and in a supercritical fluid state, and can be used in the oil and gas industry to study the physical properties of reservoir fluids (oil - associated gas) in the wellhead and pipelines. According to the first variant, the cell for studying the phase equilibrium in the gas-liquid system contains a horizontally arranged cylindrical high-pressure chamber with grooves for sealing and threaded ends at each end. The sealing grooves are provided with sealing rings, for example, made of soft metal, elastomer, rubber, to which two fixed optical windows made of sapphire, quartz or other transparent material are installed using threaded bushings screwed into the threaded ends. In the wall of the cell chamber between the optical windows, there are radial threaded holes with temperature and pressure sensors installed in them and valves for the input and output of the medium. The cell chamber between two fixed optical windows contains a movable optical window enclosed in a sleeve and installed in the housing through an internal O-ring and pressed to the housing through a threaded connection by a lid equipped with an external O-ring. A movable optical window divides the volume of the cell into a chamber for the medium under study and a chamber for hydraulic fluid. Moreover, radially arranged through holes with threads in the wall of the cell chamber, with temperature and pressure sensors installed in them and valves for the input and output of media, have both a chamber for the medium under study and a chamber for hydraulic fluid, and are as close as possible to fixed optical windows. The medium inlet valve in the chamber for the test medium is connected to the container with the test medium. The medium outlet valve in the hydraulic fluid chamber is connected to the hydraulic fluid collection tank. The cell for studying the phase equilibrium in the gas-liquid system, according to the second variant, contains a hinge inside the chamber for hydraulic fluid, a cylindrical spring is installed coaxially with the axis of which, and one of the free ends of the hinge is inserted into a vertical groove in the body of the movable optical window, the other free end of the hinge is installed at the base of the fixed optical window. In this case, the medium inlet valve in the chamber for the medium under study is connected to the tank with the medium under study, and the medium outlet valve in the chamber for hydraulic fluid is connected to the atmosphere.  
     EFFECT: invention makes it possible to increase the information content and reduce the uncertainty of measurements of properties that characterize the thermodynamic phase equilibrium in gas-liquid systems, including at high pressures and temperatures in a supercritical fluid state.  
     2 cl, 3 dwg, 6 tbl, 2 ex