Abstract: The formation of inorganic salt scale is one of the most serious problems facing the water injection and oil recovery stage in China's oilfields. The water quality of the oilfield is complex and the formation water contains high concentration of calcium, magnesium and other metal ions with strong scaling tendency. During the process from the wellbore to the ground transportation system, with the change of geological, physical and chemical factors, scaling is possible wherever there is oil, gas, water and mud flowing through. These scales may block the reservoir pore space and oil pipeline, reduce the efficiency of heat exchanger, affect the oil production seriously and increase the cost of extraction, transportation and treatment. Based on the latest domestic and international oilfield scale research data, this paper summarizes the properties, generating conditions, and influencing factors of typical oilfield scale types. It also summarizes the mainstream scale inhibition mechanisms and provides a summary of the scale prevention and removal methods that have been applied successfully at home and abroad.

Key words: oilfield scale, scale prevention, scale inhibitor, scale formation mechanism, inhibition mechanism