7 results about "Equilibrium constant" patented technology

This invention discloses a method, apparatus, equipment, and medium for predicting the dew point pressure of condensate gas. The method includes: inputting basic data of a condensate gas sample and initializing the dew point pressure value; using the 4CM splitting method to split and characterize the C7+ component in the condensate gas; estimating the gas-liquid phase equilibrium constant and the mole fraction of each component in the liquid phase based on the mole fraction of each component after splitting; calculating the gas-liquid phase compressibility factor using the improved equation of state (MPR) based on the gas-liquid phase equilibrium constant, the mole fraction of each component in the liquid phase, and the relevant data after characterization; determining whether the absolute value of the difference between the gas and liquid phase fugacity satisfies the equilibrium condition and whether the sum of the mole fractions of each component in the liquid phase satisfies the preset convergence condition; and finally outputting the calculated dew point pressure. This invention utilizes an integrated and innovative method for thermodynamic model construction, resulting in high accuracy and low calculation error in predicting the dew point pressure of condensate gas.

The embodiment of the invention provides a component phase state determination method and a component phase state determination system of a three-phase system, and belongs to the field of component numerical simulation. The method comprises the following steps: determining a gas-water initial phase equilibrium constant of each component according to a gas-oil initial phase equilibrium constant of each component in a three-phase system and a Henry law constant of a water phase; according to the physical property parameters of the three-phase system, the gas-oil phase equilibrium constant of each component and the gas-water phase equilibrium constant of each component, the phase equilibrium state of the three-phase system is determined; and under the condition that the three-phase system reaches phase equilibrium, according to the gas-oil phase equilibrium constant of each component and the gas-water phase equilibrium constant of each component, determining the molar percentage content of each component in the oil phase, the gas phase and the water phase. The component phase state determination method not only can calculate the molar percentage content of each component in an oil phase, a gas phase and a water phase, but also can simulate the influence of NaCl on the phase state and the disappearance process of the water phase.

The invention relates to the technical field of chemical process simulation, in particular to a gas-liquid flash calculation method and device, a medium and a product. The method comprises the following steps: acquiring initial parameters of a multi-component system, performing composition estimation on the multi-component system based on a preset thermodynamic equation, determining a liquid phase fugacity coefficient and a gas phase fugacity coefficient of each component, performing lower limit constraint on the fugacity coefficients, and determining a phase equilibrium constant of each component based on the constrained fugacity coefficients. The method comprises the following steps: constructing a gas phase fraction solving equation through a phase equilibrium constant and a feeding molar fraction, and determining a target expression corresponding to the gas phase fraction solving equation based on a relative size between a current gas phase fraction and a preset threshold value, so as to iteratively carry out mixed solving on the target expression to update the gas phase fraction until the gas phase fraction meets a preset convergence condition, the gas-liquid flash calculation result representing that the current phase composition of the multi-component system meets the gas-liquid two-phase equilibrium condition is obtained, so that the efficiency and the accuracy of gas-liquid flash calculation are improved.

The invention relates to the technical field of CO2 capture, and discloses a CO2 load calculation and prediction method of an amino absorbent, which comprises the following steps: constructing an amino absorbent and CO2 reaction thermodynamic model, comprising equilibrium constant expressions of all possible chemical reactions, equilibrium constants under standard temperature and pressure, a Van der Hough equation, a solution ion strength calculation formula, an H + activity coefficient calculation formula, a pH value calculation formula under an equilibrium state and a CO2 load calculation formula. The method comprises the following steps: acquiring initial parameters of an amino absorbent solution in a carbon capture system, inputting the initial parameters into a thermodynamic model, iteratively solving the change trend of the pH along with the CO2 load in the CO2 absorption process of the absorbent through an equation set, and substituting the change trend into the to-be-measured pH to obtain the CO2 load of a target amino absorbent under the to-be-measured pH. With the adoption of the method, the CO2 load can be accurately and quickly obtained only by arranging a pH probe in the carbon capture system without sampling or using dangerous chemicals, so that the method has relatively high safety and convenience, and operation errors are not easy to occur.

The present application relates to the field of oil and gas exploitation, and in particular, to a method for obtaining electrochemical properties in the process of oil and gas exploitation, comprising: constructing a chemical reaction network between shale and external fluid; constructing a surface complexation model and a diffusion double layer model, setting initial values of thermodynamic equilibrium constant and initial values of charge density of shale; obtaining theoretical values of Zeta potential through the surface complexation model and the diffusion double layer model; when the theoretical values of Zeta potential and actual values of Zeta potential meet the convergence condition, obtaining electrochemical properties of shale after contacting with external fluid; wherein the actual values of Zeta potential are measured through laboratory experiments. The theoretical values of Zeta potential obtained by the above method are relatively accurate, and multiple electrochemical properties of shale after contacting with external fluid can be efficiently and conveniently obtained based on the theoretical values of Zeta potential, which provides analysis data and scientific guidance for subsequent efficient development of shale oil reservoirs.

The invention provides a multi-dimensional attribute synchronous carbon sequestration and heavy metal stabilization effect evaluation method. In order to solve the problems of insufficient systematicness, poor timeliness and the like caused by dependence on a complex equilibrium constant or long-term observation in the prior art, a multi-parameter system covering dynamic, static and quasi-static attributes of a complex is constructed, and the active degree, the hiding capability, the movement performance and the constant performance are systematically quantified; the chemical resistance, the physical resistance, the diffusivity and the stable transformation potential of the complex are comprehensively described. The evaluation result is dynamically corrected based on the temperature fluctuation index, and the temperature sensitivity of organic matter and microbial activity in the natural environment is fully considered, so that the method better fits the actual environment change. The method is simple to operate and low in data demand, parameters can be quickly adjusted, results can be updated in real time, the response speed and precision are improved, the method is suitable for monitoring and decision making in complex and extreme environments, resource waste can be avoided, and the pertinence and timeliness of treatment measures are improved.

A method for measuring the thermodynamic parameters of corrosion products under zinc injection conditions is disclosed. This method involves detecting the characteristic peak positions of the corrosion products using Raman spectroscopy, comparing them with a standard Raman spectroscopy database to obtain the chemical structure of the corrosion products, and calibrating the peak intensities of standard samples. The concentration of the corrosion products is then obtained based on the relationship between the peak intensities and concentrations of the standard samples. AC conductivity is used to detect the conductivity of the coolant containing the corrosion products, and combined with the concentration information provided by Raman spectroscopy, the ionization constant of the corrosion products is obtained. This invention enables in-situ measurement of the thermodynamic parameters of corrosion products under zinc injection water chemistry conditions, including the chemical structure, concentration, and equilibrium constant of the corrosion products. It solves the problem of missing thermodynamic parameters of corrosion products under current zinc injection water chemistry conditions, laying the foundation for accurately predicting the deposition patterns of corrosion products under these conditions and for model development.