前置碱剂酸化解堵技术在注水井中的应用

污水回注的注水井经过长期生产，井底存在有机和无机堵塞，造成注水压力偏高，常规的酸化解堵无法清除堵塞，注水井储层伤害的主要原因是有机堵塞（包括沥青和石蜡等），粘土矿物的水化膨胀，内源和外源颗粒造成的速敏伤害。采用前置碱剂和盐酸氟硼酸复合酸解堵技术处理地层，前置碱剂酸化解堵技术将碱化和酸化两种不同工艺有机结合，能够有效解决常规酸化无效的注水井堵塞问题，同时继续和地层矿物反应，进一步改造储层，提高地层渗透率。现场应用表明，经过前置碱剂和氟硼酸复合酸的作用，能够有效清除注水井的有机和无机堵塞，改善井底渗流状况，大幅度降低注水井的注水压力。保证了油藏正常生产。

The technology of ahead alkaline agent acidizing applying in water-injection wells

By long time of producing, organic and inorganic plugging is existed in the bottom of water-injection wells and conventional acidizing can not remove the plugging. The main cause of formation damage in water-injection wells is organic plugging including bitumen, paraffin wax, mechanical impurity, clay mineral hydrating, endogenous and exogenous granula velocity sensitivity, etc.. Using alkaline agent and chlorhydric/borofluorhydric compound acid to treat formation, i. e. , alkaline agent react with plugging and remove that firstly, then borofluorhydric compound acid react with deep formation mineral, the plugging in water-injection wells which is removed difficultly by conventional a-cidizing can be prevented availably and the formation property can be improved, as well as the formation permeability can be increased because of the acid fluids react with formation mineral. Field application indicates that organic and inorganic plugging in water-injection wells has been removed effectively and fluid status in bottom hole has been improved by the act of ahead alkaline agent and borofluorhydric compound acid. Therefore, injection pressures of the wells havs been reduced evidently, successful productions havs been ensured.