Abstract: The flocculating setting of bitumen from crude oil in reservoir may plug formation and production facilities, seriously affecting normal operation in an oilfield. Hence, it is necessary to study the sedimentary mechanism of bitumen and formation damage caused from it to find scientific basis of prevention from bitumen sedimentation. According to previous understandings of bitumen sedimentary mechanism,all mechanisms about it and all factors influenced are presented in this paper,including the rea-sons in detail why bitumen sediments easily in vicinity of wellbore and causes formation damages. Also, this paper reviews about thermodynamic models for bitumen simulation such as micellar model and state equation simulation approach for bitumen sedi-mentation, and these advantages and disadvantages in real application are analyzed.

Key words: bitumen, flocculation, formation damage, plug, wettability