# A Novel Application of New High-Strength Plugging Agent in Baikouquan Oilfield
## 5 Conclusions  
In this work, a new type of micro-expansion plugging agent is proposed as an effective way to plug leakage formation and casing damaged well. More details on plugging agents were summarized, such as the design concept, compositions and their ratios, mechanism and performance characteristics. Among them, the properties of the plugging agent were evaluated, including plugging strength, temperature resistance, salt resistance, expansion and flow performance. The detailed conclusions are summarized as follows:  
1. The plugging agent is made up of a variety of materials, and its density can be adjusted within the required range to meet the plugging requirements for different formations. In addition, it can quickly form a space network structure so as to effectively reside in the plugging position and also has favorable plugging strength, temperature resistance and salt resistance, with long validity after plugging. 2. Under the condition of high temperature, the plugging strength can remain stable. Under the laboratory experiment conditions, the maximum plugging strength can reach 53 MPa, meeting the requirements of subsequent boosting pressure water injection and conventional fracturing. 3. The plugging agent has the property of micro-expansion, and the expansion rate is about 4.3%. The compactness of the solidified body is enhanced by the micro-expansion property of the plugging agent, which improves the bond strength between the solidified body and formation, casing and cement sheath, reducing the risk of late annulus pressure and gas channeling. 4. The plugging agent has favorable thixotropy, particle suspension ability, and favorable fluidity, so that the particles do not settle down in the slurry, meeting the pumping requirements for the field, which ensures construction safety. 5. The pressure test value for the plugging agent is large after plugging, which fully meets the requirements for site construction. In addition, this plugging technology can be used in cases where some production wells fail to achieve the expected production after fracturing, or casing leakage and casing faults make the fracturing impossible, requiring a rebuild of the wellbore integrity. The plugging agent presented plays an important role in reducing the production cost of oil and water wells and increases the production by a single well. It explores a new direction for plugging technology, especially in rebuilding wellbore integrity, which has great value for popularization and application. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app12168150/s1](https://www.mdpi.com/article/10.3390/app12168150/s1)]([https://www.mdpi.com/article/10.3390/app12168150/s1](https://www.mdpi.com/article/10.3390/app12168150/s1)), Figure S1: Plugging strength variation at different temperatures and different densities; Figure S2: Plugging strength variation in terms of time at 80 \({}^{\circ}\)C and 100 \({}^{\circ}\)C; Figure S3: The expansion curve of plugging agent variation over time; Table S1: Comparison of rheological properties of different density plugging agents; Figure S4: Salt resistance characteristics diagram of plugging agent; Table S2: Comparison of data with pre-construction and after construction.