高精度全压力全温度范围天然气偏差系数解析计算模型

A high-precision and whole pressure temperature range analytical calculation model of natural gas Z-factor

李相方 任美鹏 胥珍珍 徐大融 张兴全

LI Xiangfang REN Meipeng XU Zhenzhen XU Darong ZHANG Xingquan

中国石油大学石油天然气工程学院，北京　102249

Petroleum Gas Engineering in China University of Petroleum, Beijing 102249, China

天然气偏差系数是气藏储量计算和气藏动态分析中必不可少的基本参数。针对目前工程上利用的计算天然气偏差系数单个计算模型适用的压力范围很小、需要迭代才能计算、精度偏低情况，建立了一种高精度、全压力、全温度范围天然气偏差系数解析计算模型——LXF-RMP模型。该模型适合压力范围0~140 MPa，较其他计算模型计算方便，利于手工或计算机编程计算。相对误差大多在1%以下，由此分析得出，LXF-RMP模型在全压力、全温度范围的精度很高。

natural gas Z-factor is an important physical parameter in engineering calculation, and it is also a basic value in gas reserves calculation and dynamic analysis. Aimed at the current engineering calculations using a single computational model of natural gas deviation factor, whose pressure range is small and precision is low, and iterative calculations is needed, a high-precision analytical calculation model of natural gas Z-factor with whole pressure and temperature range have been set up. This model is suitable for pressure of 0~140 MPa and easier to be calculated by hand or computer. Difference and error analysis shows that, in most cases, the relative error is below 1%, thus LXF-RMP model is more precise in whole pressure and whole temperature range.