Enhanced treatment and removal of paraffi wax and asphaltene deposits from oilfi d pipelines (through the example of Kiengopskoye field)

Commercial oil production in the Udmurt Republic has been going on for more than 50 years. Continuous development of oilfi ds has gradually reduced reservoir temperature, increased water cut and made oil composition heavier. Nowadays there are many technologies aimed at prevention and removal of paraffi wax and asphaltene deposits, and each of them certainly has its benefi and drawbacks. Unfortunately, none of the existing inhibitor solutions can fully prevent wax buildup. In fact, such inhibitors only help to increase intervals between treatments. Key research objective implies the search for efficient removal of paraffin wax buildup from downhole pumping equipment, production tubing and gathering pipelines in a way that would ensure quicker treatment and smaller amount of chemicals used.
Materials and methods
Experimental and numerical methods based on ANSYS and ASPEN HYSYS CAD software.
Results
The technology for removal of paraffin wax and asphaltene deposits has been developed. It has helped to cut the time of treatment procedure and perform clean-up without shutting the pumps down. Based on math modelling, it has been found that removal of 6 mm thick deposits (mainly paraffin at an average well depth of 600 m would require thermochemical treatment in the amount of 10 m3 with further injection of 200-350 liters of solvent per operation. Field application ofthe procedure has proved the efficiency of the thermochemical and solvent treatment technique in removing paraffin wax deposits.
Сonclusions
As exemplified by the use in the given field, thermochemical and solvent treatment method for removal of paraffin wax and asphaltene deposits is by 11.5% cheaper and more efficient, as compared to the existing fresh water technique. The developed technique of replacing of 50% of solvent with heat transfer fluid will allow to cut costs, attributed to removal of paraffin wax and asphaltene buildup.