## 3 Results and Discussion
### Corrosion Protection Effect of GE-EP@OIMs in Various pH NaCl Solutions  
#### 3.3.1 Weight Loss Measurements  
The weight loss experiment was conducted to determine the actual corrosion rate of L80 in NaCl solutions, both with and without GE-EP@OIMs. The corrosion medium was replaced every 24 h to simulate the environment of oilfield-produced water. The test results are presented in Figure 13. When GE-EP@OIMs was not added, the initial corrosion rates (on day 1) at 20 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 80 \({}^{\circ}\)C were 0.3759 mm/a, 0.6560 mm/a, and 0.9508 mm/a, respectively. After adding GE-EP@OIMs, the corrosion rates at 20 \({}^{\circ}\)C, 50 \({}^{\circ}\)C, and 80 \({}^{\circ}\)C were reduced to 0.1442 mm/a, 0.3028 mm/a, and 0.4835 mm/a, respectively. This indicates that  
1. The corrosion rate of L80 carbon steel is positively correlated with the solution temperature. The higher corrosion rate at 80 \({}^{\circ}\)C can be attributed to the fact that elevated temperatures promote the migration of corrosive ions at the electrochemical reaction interface, thereby accelerating the electrochemical reaction process;  
Figure 12: The internal SEM images of GE-EP@OIMs after releasing for 60 days in different temperature solutions. (**a**): 20 \({}^{\circ}\)C, (**b**): 50 \({}^{\circ}\)C, and (**c**): 80 \({}^{\circ}\)C.  
Figure 13: Corrosion rate and inhibition efficiency of L80 in different temperature solutions of 3.5 wt.% NaCl with and without GE-EP@OIMs: (**a**) without GE-EP@OIMs and (**b**) with GE-EP@OIMs.  
The corrosion rate of L80 steel decreases gradually over time, eventually stabilizing. According to the NACE-RP0775 standard [41], the long-term (60 days) corrosion rate of L80 steel at 20 \({}^{\circ}\)C is highly corroded, while at 50 \({}^{\circ}\)C and 80 \({}^{\circ}\)C, it is severely corroded. The fact that corrosion rate of L80 carbon steel in various temperature environments exceeds 0.076 mm/a indicates the need for corrosion protection measures in oil-and-gas fields.  
As shown in Figure 13, compared to the NaCl solution alone, the corrosion rate of L80 during the immersion period (1-60 days) is consistently lower than 0.1500 mm/a, with the corrosion rate under most conditions even falling below 0.076 mm/a, indicating significant corrosion inhibition. At the same temperature, the corrosion rate of carbon steel gradually increases over time, which is attributed to the daily replacement of the NaCl solution and the gradual reduction of OIMs released by GE-EP@OIMs. The corrosion inhibition rate of GE-EP@OIMs follows different patterns at different temperatures. Specifically, at 20 \({}^{\circ}\)C, the inhibition rate gradually decreases, while at 50 \({}^{\circ}\)C, the decay is slower, with the inhibition rate remaining above 80% after 60 days of immersion. At 80 \({}^{\circ}\)C, the corrosion inhibition rate remains above 80% for the first 40 days but then decreases significantly after that. The corrosion inhibition effect of GE-EP@OIMs is due to the adsorption of the released OIM on the surface of the carbon steel. The corrosion inhibition rate and corrosion rate of L80 in different temperature environments suggest that GE-EP@OIMs is particularly effective for carbon steel corrosion protection in medium-temperature environments, although its effective inhibition time is somewhat reduced in high-temperature environments.