Abstract: The residual oilfield chemicals and products from their interaction with oil reservoirs，will badly impact the follow-up processing.In this paper，the crude oil of five western Oilfields--Karamay，Tarim，Turpan-Hami，Changqing and Qinghai，which is processed by Lanzhou Petrochemical Company，is taken as an example to study the influence of oilfield chemicals on oil processing and countermeasures.The research and analysis show that the products are three kinds，i.e.，oil-soluble，water-soluble and insoluble in oil and atmospheric and vacuum residual oil，which mainly impact the unit operations of electric desalting and dehydration of crude oil，atmospheric and vacuum distillation，FCC and delayed coking etc.Systematically research about the residue impacts on the plants，operations and product qualities of each unit operation and performance of FCC catalyst is carried out，on the basis of which，the technology，standards，information，management and countermeasures of basic research are put forward.

Key words: oilfield chemicals, reservoir improvement, residues, oil processing, unit operation, countermeasure