一种适合海上砂岩油田的单段塞活性酸体系

中国海上油田在高效开发过程中,疏松砂岩油藏存在微粒运移堵塞、泥质堵塞以及清污混注带来的无机堵塞等伤害,而采用常规酸化又面临施工规模受平台空间限制、重复酸化井多且有效期短等难题,造成酸化作业效果较差。针对这些问题,根据不同药剂之间的协同效应,通过大量实验,将盐酸、3种多步电离酸、缓蚀剂、氟碳表面活性剂、阳离子聚合物进行有效组合,并采用单一体系注入段塞的设计思路,最终开发出HX-01活性酸体系。为了便于酸液运输和节省平台作业空间,将该体系做成浓缩液,使用现场注入水和酸液混合注入,施工简单。同时,研发的体系具有现场垢样溶蚀能力强、表面张力低、黏土溶蚀能力强、骨架破坏小、深部缓速、腐蚀低、动态驱替能力强等特点,解决了海上油田酸化系列难题,并改变了现有的常规酸化施工工艺。 

Acidizing Offshore Sandstone Reservoir with a Single Slug Active Acid System

In offshore oil and gas development in China, particle migration, clay particle blocking and inorganic salt blocking during mixed water injection for sewage cleaning have caused damage to unconsolidated sandstone reservoirs. Conventional acidizing jobs in an effort to stimulating the wells drilled were restricted by those adverse factors such as limited work space on well platform, repeated acidizing jobs and short effective production time of the acidized wells, etc. In a study to solve these problems, the synergy of different additives is exploited. In laboratory experiments, HCl, three polyprotic acids, a corrosion inhibitor, a fluorocarbon surfactantand a cationic polymer are mixed in a certain ratio and order to produce a compound, the HX-01 active acid system, which is further concentrated for the ease of job. HX-01 is injected with water in a single slug into the well, greatly simplify the acidizing job. In field acidizing work, HX-01 shows those advantages such as strong scale dissolution, low surface tension, strong clay dissolution, low damage to formation matrix, reduced advancing speed deep in reservoir formations, low corrosion and high dynamic displacing capacity etc. The use of HX-01 has solved the problems encountered in offshore well acidizing jobs, and changed the operation techniques of the conventional acidizing process presently in use.