摘要
针对低渗透砂岩储层不符合达西渗流规律、其酸化增产规律与常规储层存在差异的情况,引入含启动压力梯度的低速渗流方程。在考虑储层酸化改造后,酸化半径内启动压力梯度减小甚至消失的前提下,推导出了径向稳态渗流下污染井酸化前后的产量公式,并进一步推导出了在酸化半径内完全和部分解除污染时分别对应的增产率表达式。用一算例对比分析了达西渗流与非达西渗流下低渗透储层污染井及未污染井酸化增产规律的差异。某低渗透油藏两口井酸化后的生产数据分析表明,达西定律不适用于低渗透储层酸化增产效果分析,其与广义达西定律导出公式存在较明显的差异,为低渗透储层未污染井也适宜进行酸化增产提供了理论和实践依据。
The Darcy＇s law cannot be used in the filtration flow in low permeable reservoir, and its acidizing stimulation results are different with traditional reservoir. The low velocity filtration flow equation with start-up pressure gradient was introduced. The productivity equations under radial steady flow before and after acidizing were obtained considering the reduce or diminish of the start-up pressure gradient after acidizing. The incremental ratio for partial or complete acidizing was derived. Using a example, the difference in incremental recovery resul-ting from acidizing was analyzed when using Darcy＇s law and Non-Darcy＇s law. Two production data from acidizing wells in a low permeability oilfield indicate that Darcy＇s law cannot be used in analyzing the incremental recovery in low permeability reservoir. There are obvious differences between the result using Darcy＇s and Non-Darcy＇s law. This result provides theoretical and practical support for acidizing low permeability reservoirs.
出处
《石油钻探技术》
CAS
北大核心
2008年第4期61-63,共3页
Petroleum Drilling Techniques
基金
教育部新世纪优秀人才资助项目"高含水油田热力采油技术提高采收率渗流理论与开发对策研究"(编号:NCET-06-0089)资助
关键词
低渗透储集层
酸化
启动压力梯度
达西定律
增产
low permeability reservoir
acidizing
starting pressure gradient
Darcys law
increase productivity
