低渗气井水锁伤害半径研究

水锁伤害是一个长期而持续的过程,评价水锁伤害对低渗气井产能影响时主要通过岩心水锁伤害实验实现。由于实验时间短、岩心长度小等限制,因此无法准确描述作业周期长的低渗气井水锁伤害半径。通过对水锁伤害机理分析,确定影响水锁伤害半径主要因素。结合渗流力学理论将水锁伤害过程近似为毛管束模型的活塞式运动,推导出水锁伤害半径的计算方法;并结合实际井的钻完井和测试资料,进一步验证了计算方法的准确性。运用该方法可以准确计算作业周期长的低渗气井水锁伤害的半径,准确评价其对产能的影响。

The study on water-blocking damage radius of gas wells with low permeability

water-blocking damage is one of the main factors affecting gas well deliverability of low permeability, the water locking damage is mainly through the core of water blocking experiment, as the experimental time is short, small core length limit, therefore cannot accurately describe the actual gas water-blocking damage radius of low permeability. Through the damage mechanism of the water lock analysis, determine the main factors influencing the water locking damage radius. Combined with percolation mechanics theory, the water locking damage process similar to piston movement of capillary bundle model, derives the formula for calculating the water locking damage radius, and combining with the drilling and completion and testing data of actual well, further verify the accuracy of the calculating method. Using this method can accurately calculate the low permeability gas water-blocking damage radius, guide the establishment of a reasonable way of testing.