超高温高压含CO2天然气偏差因子预测模型

在超高温高压条件下,含CO2天然气相态实验开展困难,偏差因子的变化规律认识不清,导致现有天然气偏差因子预测模型适用性不明确.通过测定不同CO2含量的天然气偏差因子,分析超高温高压条件下CO2对天然气偏差因子的影响程度,发现CO2含量的增加显著加强了含CO2天然气的可压缩性.基于实验数据,分析传统偏差因子预测模型的适用性,并通过拟合建立针对海上乐东气藏新的偏差因子经验预测模型.该模型具有可解析、精度高的优点.

Prediction Model of Deviation Factor for Natural Gas with High CO2 Content under High Temperature and Ultra-high Pressure Conditions

Under the conditions of high temperature and ultra-high pressure, it is difficult to carry out the phase behavior experiment of natural gas containing CO2, and the changing law of the deviation factor is not well understood, which will lead to the unclear applicability of the existing natural gas deviation factor prediction model. In this paper, the deviation factors of natural gas with different CO2 content are measured, and the influence of CO2 on the deviation factor of natural gas under high temperature and ultra-high pressure conditions is analyzed. It is found that the increase of CO2 content significantly enhances the compressibility of natural gas containing CO2. Based on the experimental data, the applicability of the traditional bias factor prediction model is analyzed, and a new bias factor empirical prediction model for offshore Ledong gas reservoirs is established through fitting. The model has the characteristics of resolvability and high accuracy.