低渗压裂气井水锁伤害数值模拟方法研究  

Numerical simulation of water lock damage in fractured well in low permibility reserviors

作　　者：刘子雄 李啸南 魏志鹏 LIU Zixiong;LI Xiaonan;WEI Zhipeng(China Offshore Oilfield Production Research Institute,Tianjin 300450,China)

机构地区：[1]中海油服油田生产研究院,天津300450

出　　处：《非常规油气》2024年第5期141-148,共8页Unconventional Oil & Gas

基　　金：中海油服科技项目“油藏问题诊断及增产措施方案优化研究与应用(Ⅰ期)”(YSB20YF010)。

摘　　要：为了找出压裂气井水锁伤害程度的定量评价方法,开展了压裂井水锁伤害机理研究,明确了水锁伤害的主控因素及其数值模拟表征方法,以S-1井为例,建立了精细的压裂井模型,模拟出水锁形成过程。研究结果表明:1)压裂井形成水锁伤害的主要原因是由于破胶后的压裂液流动能力差以及返排压差过大导致部分束缚水转化为可动水,形成了水锁伤害;2)水锁伤害半径主要集中在裂缝面附近3~5 m的区域;3)S-1井固体酸解水锁无效的原因是由于酸液并未突破水锁污染带,受注入液体的影响反而加剧了水锁伤害;4)采用递增压差式注入液氮解水锁,注入192 m^(3)液氮解除了S-1井水锁伤害,措施后该井无阻流量达到3.2×10^(4) m^(3),恢复正常生产。应用该方法能准确的评价水锁伤害程度,优化解水锁措施,对压后低产气井的治理有指导意义。In order to find out the quantitative evaluation method of water lock damage in fractured gas wells,the mechanism of water lock damage in fractured wells was studied,the main controlling factors of water lock damage and its numerical simulation characterization method were defined.Taking S-1 well as an example,a fine fractured well model was established to simulate the formation process of water lock.The results show that:1)The main formation reason of water lock damage in fracturing wells is that part of the irreducible water is converted into movable water due to the poor flow capacity of fracturing fluid after gelout and the high flowback differential pressure,resulting in water lock damage;2)The damage radius of water lock is mainly concentrated in the area of 3~5 m near the fracture face;3)The reason why the solid acid hydrolysis water lock in well S-1 is ineffective is that the acid liquid did not break through the water lock pollution zone,and the water lock damage was aggravated by the influence of the injected liquid;4)The liquid nitrogen was injected by incremental pressure differential method to relieve the water lock.The water lock damage of well S-1 was relieved after 192 m^(3) liquid nitrogen was injected.The open flow rate of the well reached 3.2×10^(4) m^(3),and normal production was resumed.The application of this method can accurately evaluate the water lock damage and optimize the removal treatment of water lock,which has a guiding significance for the treatment of low-production gas wells after fracturing.

关 键 词：解水锁 水锁伤害 数值模拟 返排压差 启动压力 

分 类 号：TE377[石油与天然气工程—油气田开发工程]