松辽盆地徐家围子断陷徐深气田流体相态及物理化学性质

Liquid phase and physico-chemical properties of fluids in the Xushen Gasfield,Xujiaweizi Fault-Depression of the Songliao Basin

通过实验测试并结合理论计算,本文确定了徐深气田典型区块和气层组的天然气偏差系数及PVT相态,发现天然气偏差系数受温度、压力和天然气组成的共同作用,天然气组份中CO_2含量大于80%的2口井的天然气偏差系数明显低于其它井。天然气中饱和水汽含量高低受储层温度、压力、气体组成和地层水含盐量等因素的综合影响。这为深入开展气藏储量评价、开发动态分析、气藏数值模拟和气井出水机理等研究提供了可靠的基础参数。

With variations of temperature and pressure during the processes of extraction and transportation,steam might be separated from the natural gas again, and form condensate water, thereby reduce gas well productivity and pipeline capacity. Water might be speed up corrosion of pipe, equipment and instrument done by natural gas containing HaS and CO2, affect the accuracy of gas measurement, do harm to safe production, transport and process. Moreover, the contents of saturated steam in natural gas was an important parameter to determine well producing water type. Deep burial depth of reservoir and edge-bottom water existed in lava gas reservoir of the Xushen Gasfield. The components of natural gas were complicated. With development and exploration of the reservoir, physical property parameters and their computational method of natural gas should be ascertained, so it was important to study the effect of saturated water vapor amount to the exploration, transportation and process of the natural gas. Through experimental study and theoretical calculation, the gas deviation factor, PVT phase of typical areas and gas layer of Xushen gas reservoirs were determined in this paper. The gas deviation factors were influenced by temperature, pressure and the gas constituent all together. The gas deviation factors of two wells with the CO2 contents being higher than 80% in constituent of natural gas were obviously lower than other wells. The contents of saturated steam in natural gas were affected by the reservoir temperature, pressure, the gas components and saturated water saliferous amount, which provided an assured basic parameters for the reserve estimation, dynamic system analysis, numerical simulation and water-producing mechanism of gas well.