考虑多因素的多层合采产液量劈分模式研究

Liquid production splitting of multi-layer mining considering multiple factors

油藏多层合采技术的运用逐渐广泛,产量劈分及分层评价视为重要环节,其结果影响动态储量计算的准确性及开发政策调整的可靠性。然而,常规地层系数(Kh值)产量劈分方法仍存在未充分考虑储层的连通性、压差等动态因素的不足。为厘清油藏开发过程中各分层动用情况,从达西公式等渗流理论出发,提出了一种新的产量劈分方法。该方法引入了“渗透率贡献率”这一概念,定义为各层渗透率与高中低所有层渗透率之和的比值,并综合研究了渗透率贡献率、含水率、劈分系数之间的关系,提出了不同渗透层的多层合采产量劈分模式。经过8组不同渗透率级差研究,利用多项式回归计算,建立了不同渗透层综合考虑含水率、渗透率贡献率等参数的产液劈分数学模型。通过数值模拟计算与实验测试结果对比检验,该劈分模式误差小、准确性高,满足现场应用的需要。

The application of multi-layer mining technology in reservoir is gradually extensive.Production splitting and stratification evaluation are regarded as important links,which affect the accuracy of dynamic reserve calculation and the reliability of development policy adjustment.However,the conventional formation coefficient(Kh)production splitting method still fails to fully consider the dynamic factors such as reservoir connectivity and pressure difference.Based on darcy formula and other seepage theory,a new production splitting method is put forward to clarify the role of the production of each layer in the development of reservoir.This method introduces the concept of“permeability contribution rate”,which is defined as the ratio of permeability of each layer to the sum of all permeability of high,middle and low layers,and comprehensively considers the relationship between permeability contribution rate,water content,and splitting coefficient,and proposes the production splitting of multi-layer mining with different permeability layers.Based on the research of eight groups of different permeability levels and polynomial regression calculation,the mathematical model for splitting of liquid production is established for different permeability layers considering water content,permeability range and other parameters.Through the comparison between the numerical simulation and the experimental test results,the splitting mode has small error and high accuracy,which can meet the needs of field application.