特低渗透天然砂岩大型物理模型渗流规律  

Percolation law of large-scale natural sandstone physical model with ultra-low permeability

作　　者：崔茂蕾[1,2,3] 丁云宏[4] 薛成国[5] 徐轩[1,2] 刘学伟[4] 杨正明[4] 

机构地区：[1]中国科学院渗流流体力学研究所,河北廊坊065007 [2]中国科学院研究生院,北京100190 [3]中国石化石油勘探开发研究院,北京100083 [4]中国石油勘探开发研究院廊坊分院,河北廊坊065007 [5]中国石化华北局,河南郑州450006

出　　处：《中南大学学报（自然科学版）》2013年第2期695-700,共6页Journal of Central South University:Science and Technology

基　　金：国家油气重大专项(2011ZX05013-005)

摘　　要：建立特低渗透天然砂岩大型物理模型,提出研究特低渗透油藏渗流规律的新方法。通过引入无因次产量系数的概念,分析大模型的渗流曲线,给出天然大模型的渗流特征;结合对比小岩样的非线性渗流规律和测量的平面压力梯度场,将大模型划分为死油区、非线性渗流区和拟线性渗流区。研究结果表明:特低渗透天然大模型同小岩心一样具有非线性渗流特征,相同注采压差下,渗透率越低,无因次产量系数越小,非线性渗流特征越显著;注采压差越大,无因次产量系数越大,最终趋于定值。大模型的渗流区域与注采压差、井距及模型物性有关,相同注采压差和井排距下,渗透率越低,死油区范围越大,非线性渗流区和拟线性渗流区越小;增加注采压差、缩小井排距均可缩小死油区,甚至使死油区消失,整个油藏流动能力增强。该新方法更能直观地描述实际油藏的渗流规律。A large-scale natural sandstone physical model of ultra-low permeability was established, and a new method for studying seepage law of ultra-low permeability was proposed. Seepage curves measured from the large-scale model were analyzed using the concept of dimensionless productive factor and the seepage characteristic was summarized. Combining the non-linear seepage curve of small sample core with the pressure gradient field of the large-scale model, seepage area of the model was divided into dead oil area, non-linear seepage area and quasi-linear seepage area. The results show that the non-linear seepage law still exists in large-scale model, which is the same as small cores. Under thesame pressure, the dimensionless productive factor decreases with the decrease of permeability, and the nonlinear seepage characteristic is remarkable. DPF increases up to a constant value with the increase of pressure. The scope of seepage area is related to drawdown pressure, well spacing and the physical characteristics. Large drawdown pressure and small well space reduced the dead oil area, even to disappear, which enhanced the flow ability of fluid in reservoir. This new method can describe seepage characteristic of actual reseivoir more intuitively.

关 键 词：特低渗透 大型物理模型 压力梯度场 天然砂岩 渗流规律 

分 类 号：TE311[石油与天然气工程—油气田开发工程]