低渗透致密气藏负压采气技术应用研究

THE APPLICATION OF NEGATIVE PRESSURE GAS PRODUCTION TECHNOLOGY IN CHUANXI TIGHT SANDSTONE GAS RESERVOIRS

增压开采工艺是川西致密气藏开采后期提高采收率重要手段，负压采气工艺可将废弃井口压力抽吸至负压，最大限度提高气藏采收率。总的来说，国内负压采气技术工艺配套不断发展，对负压采气潜力分析较多，但规模化应用及效果认识较少。本文在川西致密气藏负压采气潜力论证的基础上，优选燃气驱动螺杆压缩机，对48口气井实施负压采气工艺。实施负压采气后，可以提高单井日产量达46％，单井采出程度提高3．3％～10％，证实了致密气藏负压采气良好的应用前景。同时，燃气驱动螺杆压缩机性能稳定，工况范围宽，最低吸气压力可达0．01MPa；相比传统活塞压缩机，螺杆压缩机更能满足负压采气工况条件。

Recovering Technique with Booster for Late Exploitation of Chuanxi tight Sandstone Gas Field is an important means to improving the recovery of gas reservoir,Negative pressure gas recovery process can make abandoned wellhead pressure suction to be negative,so as to maximize the recovery of gas reservoir. In general,due to the domestic gas negative pressure production technology development,the negative pressure gas potential analysis is geting more and more,but the scale of the application and effect understanding is very little. Therefore,this paper demonstrates the gas potential in the negative pressure in the tight gas reservoir,and a screw compressor is chosen for a negative pressure gas production test in 48 wells. For a negative pressure gas production,daily production of single well production ratio of 46%,the single well production degree increases 3.3 ~ 10%,confirmed the negative pressure tight gas reservoir gas well application prospect. At the same time,with the performance of screw compressor stability,and wide work condition,the lowest air pressureis up to 0.01MPa; compared with the traditional piston compressor,screw compressor can meet the negative pressure gas conditions.