川西致密气藏生产后期解除水锁工艺技术

随着致密气藏的长期开发,地层压力、产能的逐年降低,水锁伤害的影响逐渐显现,严重制约了气藏采收率的提高.分析了储层岩性、孔隙结构、储层流体性质等内在因素以及施工作业环节和作业条件等外在诱发因素对储层水锁伤害的影响,明确了水锁解除剂应具有低表面张力、改变储层润湿性、除垢和低伤害的特点.通过采用表面张力测定、接触角变化测试和解除水锁性能评价等方法进行对比分析,开发出了一种新型水锁解除剂.通过现场试验发现,气井的产气量和排液量得到有效提升,证明了该药剂的有效性,为致密气藏生产后期老井的稳产提供了新的思路和方法.

Study on Technology of Breaking Water Block in Later Stage of Gas Reservoirs Production in West Sichuan

With the decreases of the formation pressure and the production, water block damage appears gradually andbecomes the main damage of tight gas reservoirs in west Sichuan.In this paper, based on the research of influencing factors,the performances of treating agent to reduce the water lock damage are low surface tension, effective wettability control andchemical scale removal.A kind of new treating agent is developed in laboratory, and the experimental results show that thisnew agent can effectively promote the water and gas production, which provides new method for the development of old gaswells in later production stage.