新场沙溪庙组沙二气藏储层致密、自然产能低,水平井作为气藏有效开发的手段之一,其采收率主控因素尚不明确。利用Eclipse数值模拟软件,研究水平井采收率主控因素并定量评价其影响程度,为利用水平井进一步开发提供理论依据。结果表明：①致密砂岩气藏不同储量区水平井采收率主控因素不同,Ⅰ类、Ⅲ类和Ⅳ类储量区水平井采收率主控因素为含水饱和度,Ⅱ类储量区水平井采收率主控因素为有效厚度。②主控因素对水平井采收率影响程度不同,Ⅰ~Ⅳ类储量区主控因素对采收率的影响幅度分别为91.14 %、54.33 %、61.82 %和45.18 %,由单一因素影响转变为多因素共同影响。③储层物性好的Ⅰ类和Ⅱ类储量区,水平井采收率受物性影响较小,采收率影响幅度不超过1 %;物性较差的Ⅲ类和Ⅳ类储量区,水平井采收率受物性影响高达17 %。所以,对于致密砂岩气藏利用水平井有效开发,需分储量区进行对策优化。物性较好区域,应加强水平井工程设计优化,例如提高水平段长度、精细造缝等;物性较差区域,应优选含水饱和度低、储层有效厚度大、渗透率高区域部署水平井。

The gas reservoir in 2^nd member of Shaximiao Formation of Xinchang Gas Field is tight, and its natural productivity is low. As one of the effective development methods, the horizontal wells has unclear main controlling factors of recovery factor. By the numerical simulation software, ECLIPSE, this problem has been analyzed and its influence has been quantitatively evaluated, so as to provide a favorable theoretical basis for the further development by horizontal wells. The results show that: 1）The main controlling factors of tight sandstone gas reservoir changes with the different reserves. For the class Ⅰ, Ⅲ and Ⅳ, it is mainly controlled by the water saturation, while for the class Ⅱ, effective thickness contributes most. 2）The influence of main controlling factors on the recovery factor of horizontal wells are different, with a degree of 91.14 %, 54.33 %, 61.82 % and 45.18 % respectively for class Ⅰ~Ⅳ and multiple factors instead of single factor. 3）The physical properties of reservoir have great influence on the recovery factor of horizontal wells. For the class Ⅰ and Ⅱ reservoir with good properties, the influence degree is less than 1 %, while that of the class Ⅲ and Ⅳ reservoir with poor properties is up to 17 %. Therefore, effective development of horizontal wells depend on the classification of reservoir by different reserves. For the areas with good properties, the optimization of engineering design should be strengthened, like increasing the length of horizontal section and fine fracturing; on the contrary, for that of poor properties, the deployment location of horizontal wells should be chosen in the areas with low water saturation, large effective reservoir thickness and high permeability.