Abstract
Flow assurance is critical and difficult for deepwater pipeline since the seawater temperature, surrounding pipeline, is usually much colder than the surface air temperature. In the deepwater, the fluid heat can be quickly lost to the water if there is no thermal insulation layer surrounding the pipe wall. When the inner wall temperature falls below the crude oil cloud point temperature, wax deposition occurs. Such problem starts when paraffin components in crude oil precipitate and deposit on the cold pipeline wall. Whereas wax precipitation during oil flow results in wax deposition and flow restriction, wax precipitation during a production shutdown results in problems when attempting to restart the flow.
In this review, wax deposition problem in flow and during the shut-in conditions are discussed. Also, proposed wax deposition physics and mechanisms are outlined. Furthermore, different wax deposition mitigation techniques are explained. These techniques include: Cold Flow, Chemical Additives and Different Pipes and Coatings Techniques. In addition, different wax deposition removal techniques are reviewed. These techniques include: Fused Chemical Reaction, Mechanical Techniques, Heat Application, Chemical Additives, Magnetic Fluid Conditioning (MFC) technology and Use of Microbial Products.
