Summary
Flow of paraffinic hydrocarbon liquids within extended pipeline networks or wells, where the environment/bulk temperature is below the cloud point or wax-appearance temperature (WAT), could result in precipitation of wax from the bulk fluid. Precipitated wax crystals from crudes deposits on the inner pipe wall could lead to reduced flow area or even complete blockage and could present a costly problem in the production and transportation of petroleum products. Timely removal of such deposits is extremely important to avoid associated problems.
This paper illustrates a numerical approach to estimate the deposition profile and its effect on flow-related parameters. Later, the procedure is validated with field data from a North Sea offshore production facility. This paper also seeks to propose a feasible solution to avoid such flow-assurance issues; in doing so, current commonly practiced reduction and preventive methods are reviewed. Previously, providing thermal insulation with aerogel foam had proved to be the most effective option in preventing wax from precipitating. A relatively new approach is discussed in this paper, which allows for minimizing the usage of insulation material in an attempt to reduce the implementation cost of the proposed precaution. Theoretical implementation of the procedure was also conducted to identify its effectiveness, which was later found to be elimination of the deposition completely.
Read or download the full SPE paper 165933-PA.
Sheikh Mohammad Samiur Rahman and Sibi Chacko, Heriot-Watt University