Objective The aim is to solve the problem of scale formation of surface water injection pipelines in Qingxi Oilfield.

Methods The influencing factors of scaling were studied by software prediction and indoor laboratory experiments, and the scale inhibition and compounding of scale inhibitor experiment were carried out by selecting the appropriate scale inhibitors.

Results The scaling prediction results show that the scaling type of surface water injection pipeline in Qingxi Oilfield is mainly calcium carbonate scale, and contains a trace amount of barium sulfate scale. The scale inhibition experiment results show that these scale inhibitors (DTPMPA, DF-501, GY-405) have good scale inhibition effect on the mixed water of the water injection pipeline, and have good compatibility with the injected water. The orthogonal test results show that pH value has the most significant effect on the scale inhibition and pressure has the least effect on the scale inhibition effect of calcium carbonate. When the total concentration of the compound scale inhibitor is 100 mg/L and the scale inhibitors DTPMPA and GY-405 are compounded with the mass ratio of 1:1, the scale inhibition rate is 92.54%; When the scale inhibitors DTPMPA, GY-405 and DF-501 are compounded with the mass ratio of 0.5:1.0:1.5, the scale inhibition rate is 95.76%.

Conclusion After the scale inhibitors are compounded, the scale inhibition performance of the scale inhibitor will be improved through the synergy between the scale inhibitors.