温度和压力对气水相对渗透率的影响

气水相对渗透率是气藏开发方案设计与开发动态指标预测、动态分析和气水分布关系研究最重要的基础参数。实验室现有的气水相对渗透率测试条件与实际地层高温高压渗流条件存在着较大差异,这可能造成测试结果不能真实地反映地下渗流特征。目前在实验温度和压力对气水相对渗透率的影响研究国内外尚存在分歧。为此,在实验室常温、较低压力条件下,测试了12块岩样气水相对渗透率曲线,并进行归一化处理;从理论上建立了实验室条件与地层条件相对渗透率曲线转换关系;并以某高温高压井为例,模拟计算了不同温度、压力对气水相对渗透率的影响。结果表明:实验温度和压力不会对水相相对渗透率曲线造成影响,而对气相相对渗透率却有很大影响,在高温、高压条件下甚至能相差超过10倍。结论指出,应谨慎考虑使用实验室条件测试的气水相对渗透率来预测地层高温高压条件的开发动态指标。

Can gas water relative permeability measured under experiment conditions be reliable for the development guidance of a real HPHT reservoir?

Gas water relative permeability is a critical parameter in the research of gas reservoir development plan design, dynamic development index prediction, dynamic analysis, and the study of gas water distribution relationship. There is a big difference between experimental conditions and actual high pressure and high temperature reservoir conditions, so the experimental results of gas water relative permeability fail to accurately reflect underground flow characteristics. There are divergent views on the effects of experimental conditions like temperature and pressure on gas water relative permeability. In this paper, gas water relative permeability curves of 12 cores were measured at room temperature and lower pressure in the laboratory and were normalized to be taken as the basic relative permeability. Moreover, a theoretical conversion model was established to transfer gas water relative permeability from experimental conditions to reservoir conditions. A high pressure and high temperature well was taken as an example to simulate and calculate the effects of different temperatures and pressures on gas water relative permeability. The results indicated that experimental temperature and pressure exert an effect on gas relative permeability instead of water relative permeability, particularly when gas relative permeability at experimental room temperature and lower pressure is 10 times higher than that at high temperature and high pressure. In conclusion, it is unadvisable to predict the reservoir development indexes at high temperature and high pressure by using gas water relative permeability figured out under experimental conditions.