致密气藏压裂水平井温度剖面影响因素分析

由于缺少水平井温度剖面预测模型,且影响温度剖面的主导因素不明确,导致根据分布式光纤温度测试数据反演解释致密气藏压裂水平井产出剖面十分困难。为此,建立了考虑多种微量热效应和裂缝系统传热的致密气藏压裂水平井温度剖面耦合预测模型,模拟分析致密气藏压裂水平井储层温度分布和井筒温度剖面特征,并采用正交实验分析和定量实验分析方法评价不同影响因素对温度剖面的影响程度。研究表明:各因素对致密气藏压裂水平井温度剖面的影响程度由大至小依次为裂缝半长、单井日产气量、储层渗透率、井筒直径、裂缝导流能力、水平段井筒倾角、储层总导热系数;主导因素为裂缝半长、单井日产气量和储层渗透率。温度模型的建立和温度剖面主导因素的确定为致密气藏压裂水平井产出剖面、裂缝参数等定量解释奠定了理论基础。

Analysis of Influencing Factors of Temperature Profile of Fractured Horizontal Wells in Tight Gas Reservoirs

The absence of horizontal well temperature profile prediction models and the unclear dominant factors affecting the temperature profile make it very difficult to invert and interpret the production profile of fractured horizontal well in tight gas reservoirs based on the temperature test data of distributed optical fiber. To this end, a coupled temperature profile prediction model was established for fractured horizontal wells in tight gas reservoirs, taking into account multiple micro thermal effects and heat transfer in the fracture system, the reservoir temperature distribution and wellbore temperature profile characteristics of fractured horizontal wells in tight gas reservoir were simulated and analyzed, and the influence of different influencing factors on temperature profile was evaluated by orthogonal experimental analysis and quantitative empirical analysis. It was found in the study that the following factors were listed in descending order according to their influence of the factors on the temperature profile of fractured horizontal wells in tight gas reservoirs: fracture half-length, daily gas production of single well, reservoir permeability, wellbore diameter, fracture conductivity, wellbore inclination in horizontal section and the total thermal conductivity of the reservoir; the dominant factors were fracture half-length, daily gas production of single well, and reservoir permeability. The establishment of the temperature model and the determination of the dominant factors of the temperature profile laid a theoretical foundation for the quantitative interpretation of the production profile and fracture parameters of the fractured horizontal wells in tight gas reservoirs.