Subsea Control of Paraffin Deposition

Baker Hughes Reduced Subsea Well Operating Expenses

A deepwater producer in the Gulf of Mexico was operating a set of subsea wells in 1,700 feet of water tied back to a floating platform four miles away. The dual flowline was an uninsulated 4” O.D. with pigging capability. The black 28 gravity oil was found by cross-polarized microscopy to have a cloud point of 93°F (34°C) and to contain 3.3% n-paraffin. The customer needed a chemical program to control the wax and reduce the frequency of pigging.

A series of coldfinger tests was conducted to identify the most suitable product available to control wax deposition in the flowline. The crude was conditioned at 180°F to ensure complete remelting of the wax. Injection of the chemical was downhole so the oil could be treated at the estimated flowing downhole temperature of 150°F (66°C). Coldfinger testing was conducted with the oil at 90°F (32°C) and the finger at 60°F (16°C). The test ran for 16 hours with the oil stirred magnetically at 300 rpm. The amount of wax deposited on the coldfingers was determined gravimetrically.

Download the PDF to read more.