砂岩油藏不同温度下相渗曲线的转换方法研究

Transform methods of relative permeability curves under different temperature of sandstone reservoir

油水相渗曲线是多相渗流和驱替分析中核心内容之一,目前实验室常规的相渗曲线测试往往不能满足地层的温度压力条件,如何正确地获取代表实际储层温度条件下的相渗曲线仍存在很大争议。采用非稳态法测试和对比研究区块Y岩样不同温度条件下油水相渗曲线的变化特征。研究结果表明:随着温度的升高,岩样的束缚水饱和度呈线性增大,而残余油饱和度呈非线性减小趋势;相同含水饱和度下油相和水相相对渗透率均增大,油水两相等渗点右移,岩石的亲水性变强。因油水相渗曲线受温度影响显著,常温条件下测试的相渗曲线不能真实地反映储层的实际渗流特征。基于相渗曲线的经验公式提出一种新的方法,可将常温下的相渗数据转换成实际油藏温度下的相渗曲线,为测试油藏高温条件下相渗曲线提供了一种可借鉴的方法。

Oil and water permeability curve is important in the analysis of muhiphase percolation and displacement. At current, per- meability curve test can＇ t meet conditions of formation temperature and pressure, and how to correctly get permeability curve under actual reservoir temperature is a controversial issue. This paper adopts unsteady method to test and compare change characteristics of oil and water permeability curves of core sample Y. The results show that bound water saturation increases linearly with tempera- ture and residual oil saturation decreases nonlinearly, in addition, the permeability of oil phase and water phase increases with same water saturation, furthermore, isotonic points of oil and water two phase move to right and the hydrophilicity is strengthened. Due to the significant impacts of temperature on oil and water permeability curves, test permeability curves can＇ t really reflect real permeability characteristics of reservoir in normal temperature. Based on empirical formula of permeability curves, a new method is proposed, which can transform permeability data under normal temperature into permeability curves under real reservoir tempera- ture, thereby providing references for testing permeability curves under high temperature.