Research and Application of Chelating Plugging Removal in Comprehensive Treatment of Low Production and Low Efficiency Wells in Bonan Oilfield

After water drive development and production in Bozhong 34-2/4 Oilfield, problems such as wellbore scaling, reservoir pollution and insufficient fluid supply have occurred, resulting in a significant decline in production. The effect of conventional acidizing plugging removal technology on barium strontium scale is poor, and the residual acid after acidizing has great influence on the oil, gas and water treatment process of offshore platform, which seriously restricts the popularization and application of conventional acidizing and plugging removal technology. In this regard, chelating plugging removal technology is developed, which can effectively remove the damage of calcium, magnesium, iron, barium, strontium and other inorganic scales. It has a series of advantages, such as strong inhibition of secondary precipitation of metal ions, long reaction time, large treatment radius, and not easy to cause secondary pollution. It has greatly enriched the technical system of oil well plugging removal, forming the unique fourth generation plugging removal technology, which provides a strong technical support for the grand goal of "stable production of 30 million in Bohai Oilfields for another 10 years". Shahejie formation of Bozhong 34-2/4 Oilfield not only effectively restored 11 lying wells, increased the utilization rate of oil wells by 61%, increased the daily oil production by 690 cubic meters, but also created a 100% efficiency in the treatment of low production and low efficiency wells .