Based on the filtration theory, the steady successive substitution method to divide the entire flow process into differentiation elements, assuming steady flow in each differentiation element is used, then substituted the stable production rate equation which is suit for the low-permeability reservoirs into each differentiation element, after integral calculation, combining with material balance equation could obtain the start-up pressure gradient. By using production data including production and pressure, this method break away from the traditional laboratory method to calculate the starting pressure gradient. At the same time this new method is applied to an oil field and compared with the measured starting pressure in laboratory, the results eonfirme the reasonableness of the new method.%以渗流理论为基础,运用稳态逐次替换法将整个渗流过程微分化,视每个微单元为稳定流动,并将适合于低渗透油藏的稳定产量公式代入每个微分单元,进行积分后,再结合物质平衡方程,最终求得启动压力梯度的理论计算公式.该方法摆脱了利用实验室求取启动压力梯度的传统方法,提出了一种运用产量和压力等生产数据的全新计算启动压力梯度的理论计算公式.同时运用该新方法对某低渗油田启动压力梯度进行了计算,并与实验室测得的数据进行对比.结果证实了新方法计算结果的合理性.
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