用界面张力法测定CO_2与原油的最小混相压力  

Determination of the minimum miscibility pressure of CO-2 and crude oil system by vanishing interfacial tension method

作　　者：彭宝仔[1] 罗虎[1] 陈光进[1] 孙长宇[1] 

机构地区：[1]中国石油大学重质油国家重点实验室,北京102249

出　　处：《石油学报》2007年第3期93-95,共3页Acta Petrolei Sinica

基　　金：国家自然科学基金项目(No.20490207);教育部科学技术研究重点项目(105107)部分成果

摘　　要：采用悬滴法，测定了在模拟地层温度为356．5K、压力为8．54～23．43MPa时的CO2与原油间的界面张力。实验发现，CO2与原油间的界面张力随压力的增加近似呈线性下降趋势。对该数据进行了线性回归，并用外推法计算出当界面张力为零时的最小混相压力为24．17MPa，与实验观测达到一次接触混相状态时的压力（23．43MPa）相比，相对误差为3．16％。采用界面张力确定CO2与原油间的最小混相压力，既可通过直接观测接触混相状态确定，也可利用所测界面张力数据进行估算，操作简单易行，且耗时少。The interracial tension data of CO2 and reservoir crude oil were measured by the pendant-drop method under the simulated -formation conditions of temperature of 356. 5K and pressure ranging from 8.54MPa to 23.43MPa. The test result indicated that the interracial tension of CO2 and reservoir crude oil decreased almost linearly as increasing pressure. The minimum miscibility pressure was determined by linearly regression of these data and extrapolating the regressed line to the point with interracial tension of zero. The determined minimum miscibility pressure agrees well with the pressure observed by experiment. The minimum miscibility pressure of CO2 and reservoir crude oil could be determined either by the miscible phase picture or by the interracial tension data. The vanishing interracial tension method is easy in operation and needs less time than the other experimental methods.

关 键 词：悬滴法 界面张力 CO2混相驱 最小混相压力 测定方法 

分 类 号：TE311[石油与天然气工程—油气田开发工程]