CO_2-原油细管试验混相判定新方法  

A New Criterion for Judging Minimum CO_2 Miscibility Pressure in Slim-tube Test

作　　者：黄海东[1] 陈百炼 章杨[1] 谢新春 任韶然[1] 

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《石油天然气学报》2012年第11期131-134,171,共4页Journal of Oil and Gas Technology

摘　　要：最小混相压力(MMP)是CO2混相驱设计中的一个重要参数,细管试验是其标准确定方法。通过常规细管试验及MMP值附近的加密试验,发现采收率在MMP附近呈曲线变化,使得采用线性拟合取交点判定MMP的方法具有较大主观性,且结果会偏小;此外,原油性质及装置设计会明显影响最终采收率,不可将采收率作为混相评价标准。以改进的三次样条插值方法为基础,提出了以插值曲线曲率最小处为MMP的新判定方法,并采用新方法重新处理了文献中的细管试验数据,将计算结果与文献给出值进行了对比。结果表明,传统的线性拟合取交点的判定方法使结果平均偏小1.4MPa,而新方法可消除主观因素的影响,更适合作为标准判定方法。Minimum miscibility pressure(MMP) was one of the key parameters in designing CO2 miscible displacement,slim-tube displacement test was the standard way to determine it.Based on conventional slim-tube displacement tests and intensified tests at pressures near MMP,the change of recovery was found to be curved one,therefore the MMP judged from the method of linear fitting was subjective and its result was small.The ultimate recovery was obviously influenced by the property of crude oil and design of testing devices,thus the recovery could not be used as the standard of miscible displacement evaluation.By using the method of improved cubic spline interpolation,a new method is proposed for determining MMP to be the pressure where the curvature of interpolation curve is minimum,and the method is used for processing the test data in the literatures.The results of literatures and the new method are compared,it shows that the traditional way of linear fitting holds a average negative deviation of 1.4MPa,the new method eliminates the impact of subjectivity.The new method is proven to be a better criterion.

关 键 词：CO2驱 细管试验 最小混相压力 判定准则 三次样条插值 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]