川东北高含硫气田天然气偏差系数变化规律

The change law of gas deviation factors of high sulfur gas fields in Northeastern Sichuan

为解决高含硫气田气体偏差系数计算公式所需基础数据较多、计算过程复杂、可靠性差等问题,对川东北地区高含硫气田具有代表性的5口气井共9个层段的实际气样进行了高压物性测试,得到了不同温度和压力下的偏差系数,并对实验结果进行了分析;选用常用的偏差系数经验公式进行了对比计算,评价了经验公式对川东北高含硫气田的适应程度。结果表明:川东北高含硫气田原始条件下的气体偏差系数与气井深度正相关;当压力大于30 MPa时,高含硫气田偏差系数与压力成线性关系;与实验结果对比,DAK计算模型平均相对误差最小,HY计算模型平均相对误差最大。

At present, there are too much basic data for the calculation formula of gas deviation factors of high sulfur gas fields, also the calculating process is too complicated with low reliability. Through the high-pressure property test of actual gas sample of nine members of five representative gas wells in the high sulfur gas fields in northeastern Sichuan, deviation factors under different temperature and pressure are obtained. Experimental results are analyzed. Comparative calculation is conducted by using the commonly used empirical formula of deviation factors. The adapt degree of the empirical formula to the high sulfur gas fields in northeastern Sichuan is evaluated. Results show that the there is positive correlation between the gas deviation factor and the gas well depth under original conditions of the high sulfur gas fields. When the pressure is higher than 30 MPa, there is linear relationship between the deviation factor and the pressure. Compared with the experimental result, the average relative error of DAK model is relatively small, while that of HY model is big.