Determination method of throttle temperature and vapor-liquid ratio of high-temperature and high-pressure complex natural gas

Abstract

The invention discloses a determination method of throttle temperature and a vapor-liquid mass ratio of high-temperature and high-pressure complex natural gas. The deviation of an existing method and existing software is over 8 DEG C when the throttled temperature of the complex natural gas containing hydrogen sulfide, carbon dioxide, condensate gas and the like with the pressure higher than 20 MPa and the temperature higher than 60 DEG C is calculated. The temperature and the vapor-liquid mass ratio after throttling can be obtained accurately according to the proposed measuring and proposed theory computing method, the deviation of the temperature is less than 3 DEG C, and the problems are solved. The procedure includes: analyzing gas component, liquid component and yield of the natural gas in a separator behind the throttle valve; measuring the pressure and the temperature before the throttling and the pressure after the throttling; obtaining basic physical property parameters of each component; and confirming the virtual critical temperature and the critical pressure of the natural gas by the adoption of improved Wong-Sandler or Lee-Kesler mixing rules, solving state equations and an isentropic throttling model, and the temperature and the vapor-liquid mass ratio after the throttling are obtained.

Description

technical field [0001] The invention relates to a high-temperature and high-pressure, H-containing 2 S, CO 2 The method for measuring and calculating the throttling temperature and gas-liquid ratio of complex natural gas, condensate gas, etc. relates to the technical field of natural gas development and utilization. It is especially suitable for the measurement and calculation of complex natural gas surface throttling temperature and gas-liquid ratio with pressure higher than 20MPa and temperature higher than 60°C. Background technique [0002] As my country's economic and social development continues to increase the demand for natural gas resources, the development of high-temperature and high-pressure gas containing H 2 S, CO 2 Complex natural gas resources such as acidic media and condensate gas have become an important direction for the development and utilization of oil and natural gas in my country. In recent years, some complex natural gas reservoirs with high tem...

AI Technical Summary

Problems solved by technology

However, the intermolecular interaction force of natural gas under high temperature and pressure is mainly repulsive force, which is obviously different from that under lower pressure; 2 S, CO 2 、H 2 For acidic or polar components such as O, these components will also have an impact on the interaction force of the hydrocarbon system (non-polar system); the combined effect of these factors leads to high temperature and high pressure, H 2 S, CO 2 、H 2 The gas-liquid phase state change, density, compressibility factor, enthalpy value and other basic physical parameters of complex natural gas are quite different from those of conventional natural gas, which are closely related to the calculation of throttling temperature.

A large number of engineering practices have shown that when the pressure is higher than 20MPa, the deviation between the temperature of high-temperature, high-pressure and complex natural gas after throttling calculated by internationally used software such as HYSYS, PIPEPHASE, and OLGA and the measured value is greater than 8°C. Based on the obtained temperature There is also a large deviation between the calculated gas-liquid ratio and the measured value

These software cannot accurately calculate the temperature and gas-liquid ratio after throttling

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