Abstract: To address the issue that oilfield heavy oil wastewater cannot meet water quality requirements when reused as boiler feedwater, research on hardness removal technology for such wastewater reuse for boilers was carried out. By analyzing the water quality characteristics of oilfield heavy oil wastewater and the limitations of conventional hardness removal processes, a hardness removal process consisting of "enhanced pretreatment + chemical pre-softening + ion exchange" is proposed. Experimental verification shows that this process exhibits remarkable advantages in improving hardness removal efficiency and reducing water hardness. It provides reliable technical support for the reuse of heavy oil wastewater as boiler feedwater and helps promote the sustainable development of oilfields.

Key words: oilfield heavy oil wastewater, reuse as boiler feedwater, hardness removal technology