Characters of Troubled Paraffin Deposits of Fukubezawa Crude Oil in Akita District

Troubles due to paraffin deposition has often been encountered in well tubing and flow line at the Sarukawa and Fukubezawa oil fields in winter. Over the years, many methods for improvement had been applied, but heating of pipe line alone was successful.In this study, in an effort to solve the trouble, the paraffin deposits were collected from well heads and the chemical components were isolated by cold precipitation, extraction, urea dewaxing and liquid chromatography. Each component was analyzed by infrared absorption spectrography, gas chromatography, ultimate analyses and molecular weight measurement. From these results, it was found that the crude oil at zero Centigrade contained a few percentage of paraffin deposits. Composition of these deposits consisted of about 70 percent saturated hydrocarbons, 15 percent asphaltens and small quantities of aromatics and resins. The quantities of deposits considerably increased under 5°C, and viscosity also greatly changed for precipitation of paraffin at the same temperature.