FRACTAL ANALYSIS OF FRACTURE INCREASING SPONTANEOUS IMBIBITION IN POROUS MEDIA WITH GAS-SATURATED
FRACTAL ANALYSIS OF FRACTURE INCREASING SPONTANEOUS IMBIBITION IN POROUS MEDIA WITH GAS-SATURATED
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DOI：
10.1142/s0129183113500563
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发表时间：
2013-08-01
影响因子：
1.9
通讯作者：
Sun, Shuyu
中科院分区：
文献类型：
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作者：
Cai, Jianchao;Sun, Shuyu
在低渗透裂缝性油藏中，毛管压力引起的润湿液向基质区块的自发渗吸被认为是一种重要的开采机制。本文提出了一个从单一平面裂隙到含气基质块体的水平方向上描述SI的解析模型。该模型基于多孔基质中孔隙的分形特征，在渗吸过程中考虑了重力的作用。润湿液体渗入基质块的累积质量与接触面积、孔隙分维、曲折度、最大孔径、孔隙度、液体密度和粘度、表面张力、接触角以及裂缝的高度和倾角等因素有关。在此基础上，分析了断口强化SI的机理。由于裂缝的作用，重力对渗吸过程是正向的。此外，离裂隙顶端越远，静水压力对渗吸作用的影响越大。单裂缝水平自吸的分形分析也为裂缝性油藏基质与裂缝系统间传质函数的标度研究提供了有益的启示。
Spontaneous imbibition (SI) of wetting liquid into matrix blocks due to capillary pressure is regarded as an important recovery mechanism in low permeability fractured reservoir. In this paper, an analytical model is proposed for characterizing SI horizontally from a single plane fracture into gas-saturated matrix blocks. The presented model is based on the fractal character of pores in porous matrix, with gravity force included in the entire imbibition process. The accumulated mass of wetting liquid imbibed into matrix blocks is related to a number of factors such as contact area, pore fractal dimension, tortuosity, maximum pore size, porosity, liquid density and viscosity, surface tension, contact angle, as well as height and tilt angle of the fracture. The mechanism of fracture-enhanced SI is analyzed accordingly. Because of the effect of fracture, the gravity force is positive to imbibition process. Additionally, the farther away from the fracture top of the pore, the more influential the hydrostatic pressure is upon the imbibition action. The presented fractal analysis of horizontal spontaneous imbibition from a single fracture could also shed light on the scaling study of the mass transfer function between matrix and fracture system of fractured reservoirs.