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文摘
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由于含启动压力梯度的渗流方程不是齐次方程,使用叠加原理对其进行求解时会引起误差。首先建立含启动压力梯度的渗流方程,然后基于PEBI网格进行数值求解,最后将数值计算的试井曲线与基于叠加原理的试井曲线进行对比。数值求解的计算结果表明:启动压力梯度使得关井后的井底压力很快稳定,并且井底压力不能恢复到原始压力,同时,关井段的压力导数曲线下掉。基于叠加原理的计算结果表明:启动压力梯度使关井后的井底压力持续上升、数百天乃至数千天都不能使恢复压力稳定,并且压力导数上翘。这不仅与数值解有很大的差别,而且也与封闭边界压力导数下掉的趋势相悖。这表明叠加原理不适用来求解含启动压力梯度的渗流方程。 |
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其他语种文摘
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Equation incorporated with threshold pressure gradient (TPG) is not homogeneous,and the error exists if it is solved based on superposition principle. A mathematical single-phase flow model incorporated with the threshold pressure gradient is proposed to describe the flow behavior in low permeability reservoirs by coupling the well storage effect. The fully implicit numerical simulation based on PEBI grid is developed to study the transient pressure response for a vertical well. Buildup pressure based on numerical simulation shows that TPG quickly makes buildup pressure stabilize,and makes buildup pressure lower than initial pressure,and thus leads to the drops of curves of pressure derivative during buildup period. However,buildup pressure based on superposition principle increases with time and cannot stabilize even after 4 800 days,which makes curves of pressure derivative go up during buildup period. Comparing well test curves based on numerical solution with well test curves based on superposition principle,we find that solution based on superposition principle is totally different from the solution based on numerical simulation,which exhibits that superposition principle cannot be used to solve flow equation incorporated with threshold pressure gradient. |
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来源
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西南石油大学学报. 自然科学版
,2015,37(4):81-89 【核心库】
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DOI
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10.11885/j.issn.1674-5086.2014.11.28.01
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关键词
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启动压力梯度
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低渗透
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PEBI网格
;
数值求解
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试井曲线
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地址
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1.
合肥工业大学应用数学系, 安徽, 合肥, 230009
2.
中国石油大庆油田测试技术服务分公司, 黑龙江, 大庆, 163453
3.
中国科学技术大学力学系, 安徽, 230027
4.
中国科学院核能安全技术研究所, 安徽, 合肥, 230031
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语种
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中文 |
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文献类型
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研究性论文 |
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ISSN
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1674-5086 |
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学科
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石油、天然气工业 |
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基金
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国家重大科技专项
;
国家973计划
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中国科学院战略性先导科技专项
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文献收藏号
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CSCD:5484928
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