Oilfields that have undergone years of exploration and development inevitably face issues like well corrosion and scaling, which hinder normal production. How can we effectively restore wells, prevent corrosion and scale, extend pump maintenance cycles, increase well availability, and achieve stable oil production growth?

　　Through over a decade of relentless research, North China Oilfield has achieved significant results in well corrosion and scale prevention technology. To date, corrosion and scale inhibition technology has been implemented in 420 wells at North China Oilfield. The average pump maintenance interval has increased from 181 days before implementation to 834 days, reducing pump maintenance operations by 1,521 well-times. The input-output ratio reached 1:5.6, demonstrating significant economic benefits.

Building on this foundation, North China Oilfield expanded the technology to surface systems, implementing it at five stations. Post-implementation, corrosion rates were controlled below 0.076 mm/year, perforation rates decreased by an average of 56%, and carbonate scale inhibition rates reached 95%, providing crucial technical support for oilfield production. Diagnosing Wells, Identifying Root Causes for Scientific Treatment Over 30% of North China Oilfield's wells suffer from corrosion and scaling. This challenge impacts production, and only by pinpointing the root causes can solutions be effectively implemented.

　　Researchers prioritized wells with severe corrosion and scaling issues for targeted remediation, focusing on complex problems rather than spreading resources thinly. Researchers discovered that five wells in the Jing 22 and Jing 58 blocks of the Biegu Zhuang Oilfield, operated by the Fourth Oil Production Plant, suffered from severe corrosion and scaling that disrupted normal production. Pump maintenance became frequent, with an average maintenance cycle of 100 days. Among these, Well Jing 22-5 had an average maintenance cycle of just 67 days, significantly increasing operational costs.

　　Consequently, in 2000, the Engineering Technology Research Institute established a dedicated project team to conduct systematic research after thorough investigation and analysis. Through on-site sampling and meticulous analysis, the team identified the corrosion and scaling causes as electrochemical corrosion triggered by low pH levels, free carbon dioxide, and high mineralization in sodium bicarbonate-type water. This prompted the institute to initiate targeted corrosion inhibitor research.

　　Over six months, the team conducted thousands of laboratory tests, identifying that oxygen introduced during experiments hindered inhibitor development. Subsequently, adhering to the “one well, one inhibitor” principle, researchers successfully formulated a proprietary corrosion inhibitor with independent intellectual property rights.

　　Field validation yielded preliminary success: five severely corroded and scaled wells in the Biegu Zhuang Oilfield remained free of corrosion-related pump maintenance for one year post-implementation. This effective treatment opened broader application prospects for the technology. Deployed across five additional oil and gas production units on 420 wells, it extended average pump maintenance intervals by 3.6 times. At Oil Production Plant No. 2 alone, the average pump inspection cycle was extended by 770 days, saving over 30 million yuan in operational costs and materials like replacement rods and tubing, thereby extending the operational lifespan of the wells.