摘要
各向异性、启动压力梯度和应力敏感现象是低渗油藏最显著的特征。建立了同时考虑以上三因素的低速非达西渗流数学模型,考虑方程强烈的非线性,用近似的解法求出稳定渗流以及不稳定渗流方程的解;根据物质平衡原理,得到了定产量、变产量和定流压生产时动边界的运动规律、地层压力分布特征以及产量变化规律。结果表明,各向异性地层激动区边界以椭圆形式向外拓展,改变了井网合理井排距;启动压力梯度和应力敏感使油井产能降低,边界移动速度变慢,单井控制面积减小,增大了油藏的开采难度。
Eolotropy, threshold pressure gradient and stress sensitivity are unique feature of low-permeability reservoir. The authors of this paper build mathematical model of low-velocity non-Darcy flow through porous media, which takes three factors above mentioned into consideration. Because of non-linear for equations, approximate solution is used to solve steady flow and unsteady flow. Meanwhile, under the condition of fixed production and variable production as well as fixed BHP, movement rule of dynamic boundary, reservoir pressure characteristic and production change rule are solved by means of material balance mechanism. The results show that stimulative region boundary of eolotropy reservoir extends outward in the pattern of ellipse, which changes reasonable well row spacing; the factors of threshold pressure gradient and stress sensitivity make productivity decline, and the speed of boundary movement becomes slower, and single well control size reduces. It becomes more and more difficult to develop this kind of reservoir.
出处
《西南石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2007年第5期48-52,共5页
Journal of Southwest Petroleum University(Science & Technology Edition)
基金
国家自然科学基金(90210019)
教育部高等学校博士学科点专项科研基金(20060425001)
教育部新世纪优秀人才支持计划(NCET-05-0108)
关键词
低渗透
各向异性
启动压力梯度
应力敏感
数学模型
low-permeability
eolotropy
threshold pressure gradient
stress sensitivity
mathematical model
