# A Novel Application of New High-Strength Plugging Agent in Baikouquan Oilfield
## 4 Field Application and Effect Analysis  
Taking well 1404 as an example, located in the Bai 21 well area of the Baikouquan Oilfield, Bai 59 Station, which was put into production on 1 November 2008. The drilling depth is 2256 m, twoopen well structure, as shown in Figure 9. The depth of the surface casing is 206.64 m, with the top depth of cement to the ground and the depth of the production casing being 2247.334 m, with the top depth of cement being 815 m. The range of production formation is 2104.5-2181.5 m, with a thickness of 77 m. In order to satisfy production requirements, the supplementary formation 2104.5-2123.0 m was subsequently perforated and produced. Then the phenomena of high liquid production and high water cut appeared in well 1404. The daily liquid production was 26.5 t, the daily oil production was 1.8 t, and the water content was 93.2%. According to the above data, it can be determined that the supplementary formation is the main water outlet layer. It is worth pointing out that the gel plugging agent used previously to solve the high water cut problems had failed to plug the well many times. The problems at the construction site were mainly the retention of the gel plugging agent near the wellbore and the bearing capacity after plugging. Therefore, the plugging agent we presented was used to plug 2104.5-2123.0 m to prepare for the next operation. Figure 8: Salt resistance characteristics diagram of plugging agent. Figure 9: Well structure of Baikouquan well. The construction technological process is shown in Figure 10. Pulled out the tubing, and made a wiper trip to the artificial well bottom to ensure the borehole operation channel opened during the construction procedure. The seal packer checking casing was installed at 2100 m, controlling the pressure at 18 MPa to check the qualification of the casing, and the casing was normal. Then, the electric cable bridge plug was installed to make sure the sealing between 2123 m and 2133 m was qualified. In order to prepare the plugging slurry used, subsequently, the formation absorption was tested. The absorption was 300 L/min when the pump pressure was 3 MPa. Therefore, the parameters for the plugging agent slurry used were 1.70-1.75 g/cm\({}^{3}\), 9 m\({}^{3}\), and a thickening time of 180 min at 50 \({}^{\circ}\)C. The depth of the working string sent to the wellbore was 1800 m, pumping in ahead fluid 4 m\({}^{3}\), plugging agent slurry 9 m\({}^{3}\), overflush fluid 6.5 m\({}^{3}\) in turn with positive extrusion, and the plugging slurry level at this time was about 1883 m. Then, 2.2 m\({}^{3}\) overflush fluid was pumped in with reverse extrusion, and the plugging slurry level at this time was about 2070 m. Shut in the well, and solidified 72 h under the shutoff pressure. The leakage formation was successfully plugged under the condition that the oilfield pressure test value was 30 MPa, which meets the production requirements. The sweeping plug section 2070-2123 m was drilled under a drilling pressure of 1-3 t. The pressure test value for the sweeping plug section was 30 MPa, and the pressure did not drop for 30 min, suggesting that the high water layer 2104.5-2181.5 m was effectively plugged. After treatment, the daily fluid production of the well reduced by 46%, daily oil production increased from 1.8 t/d to 2.5 t/d, and water content decreased by 11.4%. These field data proved that the plugging agent has a favorable plugging effect. A total of four wells were plugged with the new micro-expansion plugging agent, in the Baikouquan block, including three wells with a strong water-flooded layer and one well with an upper casing leakage point. The field test showed that the leakage formation was successfully plugged under the condition that the oilfield pressure test value was 30 MPa rather than 15 MPa, with a 100% success rate. The average fluid volume decreased by 51.4%, the average oil volume increased by 270.8%, and the average daily oil production of a single well increased by 3.2 t/d.