致密气藏压裂水平井递减分析方法对比研究

Comparative study on decline analysis method of fractured horizontal well in tight gas reservoir

近年来,随着致密气藏勘探开发的不断深入,不同的致密气藏递减分析方法应运而生,但由于致密气藏特殊的储层特征及现场施工特点,并不是每一种递减分析方法都适用于所有的致密气藏压裂水平井的产能预测,合理地选择递减分析方法至关重要。本文在调研国内外致密气藏递减分析研究进展的基础上,结合加拿大蒙特尼致密气井实例,对比分析了国内外致密气藏产能分析的三种主流方法,包括Arps法、时间相关的双指数递减法和Duong法。对比分析表明,Arps法分析致密气藏递减曲线递减率大于1,预测结果偏差较大;时间相关的双指数递减法虽然考虑了流体和岩石物性的变化,但后期拟合效果变差,而Duong方法明确了裂缝控制流动阶段,使得预测结果更加准确。该结论为致密气藏开发选择合理的递减分析方法提供了必要的理论依据。

In recent years,with the deepening of exploration and development of tight gas reservoirs,different decline analysis methods for tight gas reservoirs have emerged as the times require,but due to the special reservoir characteristics and field construction characteristics of tight gas reservoirs,not every decline analysis.The methods are applicable to the productivity prediction of all fractured horizontal wells.It is important to choose a reasonable decline analysis method.On the basis of investigating the research progress of declining analysis of tight gas reservoirs at home and abroad,and combining the examples of Montenei tight gas wells in Canada,this paper compares and analyzes three mainstream productivity analysis methods of tight gas reservoir at home and abroad,including the Arps method,time-dependent double exponential declining and Duong method.Comparative analysis shows that the decline rate of the decline curve of tight gas reservoirs analyzed by the Arps method is greater than 1,and the prediction results have a large deviation;although the time-dependent double-exponential decrease method takes into account changes in fluid and rock physical properties,the later fitting effect becomes worse,and Duong method clarifies the fracture control flow stage,making the prediction result more accurate.This conclusion provides the necessary theoretical basis for selecting a reasonable decline analysis method for tight gas reservoir development.