顺北油气田主干断裂带深穿透酸化技术

Acidizing Technology for Deep Penetration in Main Fault Zone of Shunbei Oil and Gas Field

顺北油气田主干断裂带碳酸盐岩储层裂缝发育,钻井过程中井壁易垮塌掉块,超深水平井中岩屑难以返出,且部分井钻井液漏失量大,造成储层堵塞严重,常规酸化技术无法解除污染,稳产难度大。为此,通过优选解堵酸及优化施工参数等攻关研究,形成了"近井解堵+远井疏通"的主干断裂带深穿透酸化技术,其基本原理为:近井地带采用低黏度、反应速度快的酸液,快速扩散形成各向蚓孔,穿透污染带;远井地带大排量、较大规模地注入高黏酸液,对远井通道进行疏通,建立高导流渗流通道。该酸化技术在顺北油气田应用6井次,酸化效果显著,同时解决了近井和远井供液通道堵塞的问题,累计增产油量16.06×10^4 t。现场应用结果表明,该酸化技术可以解决顺北油气田主干断裂带碳酸盐岩储层的堵塞问题,对国内外类似储层酸化解堵具有借鉴价值。

Due to fractures developed in the carbonate reservoirs of main fault zones in the Shunbei Oil and Gas Field,the well wall is prone to sloughing and falling frequently during drilling,and the cuttings in ultra-deep horizontal well have very difficult flow back,along with serious leakage in some wells.The cuttings accumulation and serious leakage cause the payzone to be blocked heavily,and this blockage cannot be removed by conventional acidizing technologies.In fact,they experience great difficulty in keeping stable production.In order to solve the problem,the team developed a working hypothesis and then tested it.The low-viscosity and quick reaction acid was used in near the wellbore to create wormholes by rapid diffusion penetrating damage zone,while large amount of high-viscosity acid was injected to far wellbore zone to create high-conductivity channels.On this basis,a deep penetration acidizing technology in the main fault zone was developed,featuring“plug removal near wellbore and channeling far from wellbore”.This technology has been applied to 6 wells,resulting in cumulative oil increment of 16.06×10^4 t,which shows great acidizing effects and resolves the problems of payzone blocking near and far from the wellbore.Field application results showed that the technology could effectively solve the blocking problems of main fault zone in Shunbei oil and gas field,and provide a reference for acidizing and plug removal of similar carbonate reservoirs at home and abroad.